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srparser_app.html
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<h1>Source code for nltk.app.srparser_app</h1><div class="highlight"><pre>
<span></span><span class="c1"># Natural Language Toolkit: Shift-Reduce Parser Application</span>
<span class="c1">#</span>
<span class="c1"># Copyright (C) 2001-2021 NLTK Project</span>
<span class="c1"># Author: Edward Loper <edloper@gmail.com></span>
<span class="c1"># URL: <https://www.nltk.org/></span>
<span class="c1"># For license information, see LICENSE.TXT</span>
<span class="sd">"""</span>
<span class="sd">A graphical tool for exploring the shift-reduce parser.</span>
<span class="sd">The shift-reduce parser maintains a stack, which records the structure</span>
<span class="sd">of the portion of the text that has been parsed. The stack is</span>
<span class="sd">initially empty. Its contents are shown on the left side of the main</span>
<span class="sd">canvas.</span>
<span class="sd">On the right side of the main canvas is the remaining text. This is</span>
<span class="sd">the portion of the text which has not yet been considered by the</span>
<span class="sd">parser.</span>
<span class="sd">The parser builds up a tree structure for the text using two</span>
<span class="sd">operations:</span>
<span class="sd"> - "shift" moves the first token from the remaining text to the top</span>
<span class="sd"> of the stack. In the demo, the top of the stack is its right-hand</span>
<span class="sd"> side.</span>
<span class="sd"> - "reduce" uses a grammar production to combine the rightmost stack</span>
<span class="sd"> elements into a single tree token.</span>
<span class="sd">You can control the parser's operation by using the "shift" and</span>
<span class="sd">"reduce" buttons; or you can use the "step" button to let the parser</span>
<span class="sd">automatically decide which operation to apply. The parser uses the</span>
<span class="sd">following rules to decide which operation to apply:</span>
<span class="sd"> - Only shift if no reductions are available.</span>
<span class="sd"> - If multiple reductions are available, then apply the reduction</span>
<span class="sd"> whose CFG production is listed earliest in the grammar.</span>
<span class="sd">The "reduce" button applies the reduction whose CFG production is</span>
<span class="sd">listed earliest in the grammar. There are two ways to manually choose</span>
<span class="sd">which reduction to apply:</span>
<span class="sd"> - Click on a CFG production from the list of available reductions,</span>
<span class="sd"> on the left side of the main window. The reduction based on that</span>
<span class="sd"> production will be applied to the top of the stack.</span>
<span class="sd"> - Click on one of the stack elements. A popup window will appear,</span>
<span class="sd"> containing all available reductions. Select one, and it will be</span>
<span class="sd"> applied to the top of the stack.</span>
<span class="sd">Note that reductions can only be applied to the top of the stack.</span>
<span class="sd">Keyboard Shortcuts::</span>
<span class="sd"> [Space]\t Perform the next shift or reduce operation</span>
<span class="sd"> [s]\t Perform a shift operation</span>
<span class="sd"> [r]\t Perform a reduction operation</span>
<span class="sd"> [Ctrl-z]\t Undo most recent operation</span>
<span class="sd"> [Delete]\t Reset the parser</span>
<span class="sd"> [g]\t Show/hide available production list</span>
<span class="sd"> [Ctrl-a]\t Toggle animations</span>
<span class="sd"> [h]\t Help</span>
<span class="sd"> [Ctrl-p]\t Print</span>
<span class="sd"> [q]\t Quit</span>
<span class="sd">"""</span>
<span class="kn">from</span> <span class="nn">tkinter</span> <span class="kn">import</span> <span class="n">Button</span><span class="p">,</span> <span class="n">Frame</span><span class="p">,</span> <span class="n">IntVar</span><span class="p">,</span> <span class="n">Label</span><span class="p">,</span> <span class="n">Listbox</span><span class="p">,</span> <span class="n">Menu</span><span class="p">,</span> <span class="n">Scrollbar</span><span class="p">,</span> <span class="n">Tk</span>
<span class="kn">from</span> <span class="nn">tkinter.font</span> <span class="kn">import</span> <span class="n">Font</span>
<span class="kn">from</span> <span class="nn">nltk.draw</span> <span class="kn">import</span> <span class="n">CFGEditor</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">,</span> <span class="n">tree_to_treesegment</span>
<span class="kn">from</span> <span class="nn">nltk.draw.util</span> <span class="kn">import</span> <span class="n">CanvasFrame</span><span class="p">,</span> <span class="n">EntryDialog</span><span class="p">,</span> <span class="n">ShowText</span><span class="p">,</span> <span class="n">TextWidget</span>
<span class="kn">from</span> <span class="nn">nltk.parse</span> <span class="kn">import</span> <span class="n">SteppingShiftReduceParser</span>
<span class="kn">from</span> <span class="nn">nltk.tree</span> <span class="kn">import</span> <span class="n">Tree</span>
<span class="kn">from</span> <span class="nn">nltk.util</span> <span class="kn">import</span> <span class="n">in_idle</span>
<span class="sd">"""</span>
<span class="sd">Possible future improvements:</span>
<span class="sd"> - button/window to change and/or select text. Just pop up a window</span>
<span class="sd"> with an entry, and let them modify the text; and then retokenize</span>
<span class="sd"> it? Maybe give a warning if it contains tokens whose types are</span>
<span class="sd"> not in the grammar.</span>
<span class="sd"> - button/window to change and/or select grammar. Select from</span>
<span class="sd"> several alternative grammars? Or actually change the grammar? If</span>
<span class="sd"> the later, then I'd want to define nltk.draw.cfg, which would be</span>
<span class="sd"> responsible for that.</span>
<span class="sd">"""</span>
<span class="k">class</span> <span class="nc">ShiftReduceApp</span><span class="p">:</span>
<span class="sd">"""</span>
<span class="sd"> A graphical tool for exploring the shift-reduce parser. The tool</span>
<span class="sd"> displays the parser's stack and the remaining text, and allows the</span>
<span class="sd"> user to control the parser's operation. In particular, the user</span>
<span class="sd"> can shift tokens onto the stack, and can perform reductions on the</span>
<span class="sd"> top elements of the stack. A "step" button simply steps through</span>
<span class="sd"> the parsing process, performing the operations that</span>
<span class="sd"> ``nltk.parse.ShiftReduceParser`` would use.</span>
<span class="sd"> """</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">grammar</span><span class="p">,</span> <span class="n">sent</span><span class="p">,</span> <span class="n">trace</span><span class="o">=</span><span class="mi">0</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sent</span> <span class="o">=</span> <span class="n">sent</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_parser</span> <span class="o">=</span> <span class="n">SteppingShiftReduceParser</span><span class="p">(</span><span class="n">grammar</span><span class="p">,</span> <span class="n">trace</span><span class="p">)</span>
<span class="c1"># Set up the main window.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span> <span class="o">=</span> <span class="n">Tk</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s2">"Shift Reduce Parser Application"</span><span class="p">)</span>
<span class="c1"># Animations. animating_lock is a lock to prevent the demo</span>
<span class="c1"># from performing new operations while it's animating.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate</span> <span class="o">=</span> <span class="n">IntVar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="c1"># = medium</span>
<span class="c1"># The user can hide the grammar.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span> <span class="o">=</span> <span class="n">IntVar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<span class="c1"># Initialize fonts.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_fonts</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="c1"># Set up key bindings.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_bindings</span><span class="p">()</span>
<span class="c1"># Create the basic frames.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_menubar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_buttons</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_feedback</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_grammar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_canvas</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="c1"># A popup menu for reducing.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_reduce_menu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="c1"># Reset the demo, and set the feedback frame to empty.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="c1">#########################################</span>
<span class="c1">## Initialization Helpers</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_init_fonts</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">root</span><span class="p">):</span>
<span class="c1"># See: <http://www.astro.washington.edu/owen/ROTKFolklore.html></span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">font</span><span class="o">=</span><span class="n">Button</span><span class="p">()[</span><span class="s2">"font"</span><span class="p">])</span>
<span class="n">root</span><span class="o">.</span><span class="n">option_add</span><span class="p">(</span><span class="s2">"*Font"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span><span class="p">)</span>
<span class="c1"># TWhat's our font size (default=same as sysfont)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">=</span> <span class="n">IntVar</span><span class="p">(</span><span class="n">root</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span><span class="o">.</span><span class="n">cget</span><span class="p">(</span><span class="s2">"size"</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">family</span><span class="o">=</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="n">weight</span><span class="o">=</span><span class="s2">"bold"</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">())</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_font</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">family</span><span class="o">=</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">())</span>
<span class="k">def</span> <span class="nf">_init_grammar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="c1"># Grammar view.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span> <span class="o">=</span> <span class="n">listframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist_label</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span><span class="p">,</span> <span class="n">text</span><span class="o">=</span><span class="s2">"Available Reductions"</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist_label</span><span class="o">.</span><span class="n">pack</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span> <span class="o">=</span> <span class="n">Listbox</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="p">,</span>
<span class="n">selectmode</span><span class="o">=</span><span class="s2">"single"</span><span class="p">,</span>
<span class="n">relief</span><span class="o">=</span><span class="s2">"groove"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"#909090"</span><span class="p">,</span>
<span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">,</span>
<span class="n">selectforeground</span><span class="o">=</span><span class="s2">"#004040"</span><span class="p">,</span>
<span class="n">selectbackground</span><span class="o">=</span><span class="s2">"#c0f0c0"</span><span class="p">,</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"right"</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_productions</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">grammar</span><span class="p">()</span><span class="o">.</span><span class="n">productions</span><span class="p">())</span>
<span class="k">for</span> <span class="n">production</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="s2">"end"</span><span class="p">,</span> <span class="p">(</span><span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">production</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">height</span><span class="o">=</span><span class="nb">min</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">),</span> <span class="mi">25</span><span class="p">))</span>
<span class="c1"># Add a scrollbar if there are more than 25 productions.</span>
<span class="k">if</span> <span class="mi">1</span><span class="p">:</span> <span class="c1"># len(self._productions) > 25:</span>
<span class="n">listscroll</span> <span class="o">=</span> <span class="n">Scrollbar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="p">,</span> <span class="n">orient</span><span class="o">=</span><span class="s2">"vertical"</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">yscrollcommand</span><span class="o">=</span><span class="n">listscroll</span><span class="o">.</span><span class="n">set</span><span class="p">)</span>
<span class="n">listscroll</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">yview</span><span class="p">)</span>
<span class="n">listscroll</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"y"</span><span class="p">)</span>
<span class="c1"># If they select a production, apply it.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<<ListboxSelect>>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_prodlist_select</span><span class="p">)</span>
<span class="c1"># When they hover over a production, highlight it.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_hover</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Motion>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_highlight_hover</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Leave>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_clear_hover</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_bindings</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># Quit</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-q>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-x>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-q>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-x>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="c1"># Ops (step, shift, reduce, undo)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<space>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">step</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<s>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-s>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-s>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<r>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-r>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-r>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Delete>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<u>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-u>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-u>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-z>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<BackSpace>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">)</span>
<span class="c1"># Misc</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-p>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">postscript</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-h>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">help</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<F1>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">help</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-g>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">edit_grammar</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-t>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">edit_sentence</span><span class="p">)</span>
<span class="c1"># Animation speed control</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"-"</span><span class="p">,</span> <span class="k">lambda</span> <span class="n">e</span><span class="p">,</span> <span class="n">a</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">:</span> <span class="n">a</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">20</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"="</span><span class="p">,</span> <span class="k">lambda</span> <span class="n">e</span><span class="p">,</span> <span class="n">a</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">:</span> <span class="n">a</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">10</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"+"</span><span class="p">,</span> <span class="k">lambda</span> <span class="n">e</span><span class="p">,</span> <span class="n">a</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">:</span> <span class="n">a</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">4</span><span class="p">))</span>
<span class="k">def</span> <span class="nf">_init_buttons</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="c1"># Set up the frames.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_buttonframe</span> <span class="o">=</span> <span class="n">buttonframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="n">buttonframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"none"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"bottom"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Step"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90c0d0"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">step</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Shift"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90f090"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Reduce"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90f090"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Undo"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#f0a0a0"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_menubar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="n">menubar</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="n">filemenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">filemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Reset Parser"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Del"</span>
<span class="p">)</span>
<span class="n">filemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Print to Postscript"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">postscript</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-p"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">filemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Exit"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-x"</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"File"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">filemenu</span><span class="p">)</span>
<span class="n">editmenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">editmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Edit Grammar"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">5</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">edit_grammar</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-g"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">editmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Edit Text"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">5</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">edit_sentence</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-t"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Edit"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">editmenu</span><span class="p">)</span>
<span class="n">rulemenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Step"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">step</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Space"</span>
<span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_separator</span><span class="p">()</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Shift"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-s"</span>
<span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Reduce"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-r"</span>
<span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_separator</span><span class="p">()</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Undo"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">undo</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-u"</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Apply"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">rulemenu</span><span class="p">)</span>
<span class="n">viewmenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_checkbutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Show Grammar"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_toggle_grammar</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_separator</span><span class="p">()</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Tiny"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Small"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">12</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Medium"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">14</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Large"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">18</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Huge"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">24</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"View"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">viewmenu</span><span class="p">)</span>
<span class="n">animatemenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"No Animation"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">,</span> <span class="n">value</span><span class="o">=</span><span class="mi">0</span>
<span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Slow Animation"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">20</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"-"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Normal Animation"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"="</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Fast Animation"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">4</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"+"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Animate"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">animatemenu</span><span class="p">)</span>
<span class="n">helpmenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">helpmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"About"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">about</span><span class="p">)</span>
<span class="n">helpmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Instructions"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">help</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"F1"</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Help"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">helpmenu</span><span class="p">)</span>
<span class="n">parent</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">menu</span><span class="o">=</span><span class="n">menubar</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_feedback</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_feedbackframe</span> <span class="o">=</span> <span class="n">feedbackframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="n">feedbackframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"x"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"bottom"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">3</span><span class="p">,</span> <span class="n">pady</span><span class="o">=</span><span class="mi">3</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper_label</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="n">feedbackframe</span><span class="p">,</span> <span class="n">text</span><span class="o">=</span><span class="s2">"Last Operation:"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper_label</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">lastoperframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">feedbackframe</span><span class="p">,</span> <span class="n">relief</span><span class="o">=</span><span class="s2">"sunken"</span><span class="p">,</span> <span class="n">border</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="n">lastoperframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"x"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"right"</span><span class="p">,</span> <span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">5</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="n">lastoperframe</span><span class="p">,</span> <span class="n">foreground</span><span class="o">=</span><span class="s2">"#007070"</span><span class="p">,</span> <span class="n">background</span><span class="o">=</span><span class="s2">"#f0f0f0"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="n">lastoperframe</span><span class="p">,</span>
<span class="n">anchor</span><span class="o">=</span><span class="s2">"w"</span><span class="p">,</span>
<span class="n">width</span><span class="o">=</span><span class="mi">30</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"#004040"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#f0f0f0"</span><span class="p">,</span>
<span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">,</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"x"</span><span class="p">,</span> <span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_canvas</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span> <span class="o">=</span> <span class="n">CanvasFrame</span><span class="p">(</span>
<span class="n">parent</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="n">width</span><span class="o">=</span><span class="mi">525</span><span class="p">,</span>
<span class="n">closeenough</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span>
<span class="n">border</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span>
<span class="n">relief</span><span class="o">=</span><span class="s2">"sunken"</span><span class="p">,</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"top"</span><span class="p">,</span> <span class="n">pady</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="n">canvas</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">canvas</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span> <span class="o">=</span> <span class="p">[]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span> <span class="o">=</span> <span class="p">[]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_titlebar</span> <span class="o">=</span> <span class="n">canvas</span><span class="o">.</span><span class="n">create_rectangle</span><span class="p">(</span>
<span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"#c0f0f0"</span><span class="p">,</span> <span class="n">outline</span><span class="o">=</span><span class="s2">"black"</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_exprline</span> <span class="o">=</span> <span class="n">canvas</span><span class="o">.</span><span class="n">create_line</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">dash</span><span class="o">=</span><span class="s2">"."</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stacktop</span> <span class="o">=</span> <span class="n">canvas</span><span class="o">.</span><span class="n">create_line</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"#408080"</span><span class="p">)</span>
<span class="n">size</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="o">+</span> <span class="mi">4</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span> <span class="o">=</span> <span class="n">TextWidget</span><span class="p">(</span>
<span class="n">canvas</span><span class="p">,</span> <span class="s2">"Stack"</span><span class="p">,</span> <span class="n">color</span><span class="o">=</span><span class="s2">"#004040"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span> <span class="o">=</span> <span class="n">TextWidget</span><span class="p">(</span>
<span class="n">canvas</span><span class="p">,</span> <span class="s2">"Remaining Text"</span><span class="p">,</span> <span class="n">color</span><span class="o">=</span><span class="s2">"#004040"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span><span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Main draw procedure</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_redraw</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">scrollregion</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">[</span><span class="s2">"scrollregion"</span><span class="p">]</span><span class="o">.</span><span class="n">split</span><span class="p">()</span>
<span class="p">(</span><span class="n">cx1</span><span class="p">,</span> <span class="n">cy1</span><span class="p">,</span> <span class="n">cx2</span><span class="p">,</span> <span class="n">cy2</span><span class="p">)</span> <span class="o">=</span> <span class="p">(</span><span class="nb">int</span><span class="p">(</span><span class="n">c</span><span class="p">)</span> <span class="k">for</span> <span class="n">c</span> <span class="ow">in</span> <span class="n">scrollregion</span><span class="p">)</span>
<span class="c1"># Delete the old stack & rtext widgets.</span>
<span class="k">for</span> <span class="n">stackwidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">destroy_widget</span><span class="p">(</span><span class="n">stackwidget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">rtextwidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">destroy_widget</span><span class="p">(</span><span class="n">rtextwidget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span> <span class="o">=</span> <span class="p">[]</span>
<span class="c1"># Position the titlebar & exprline</span>
<span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="o">.</span><span class="n">bbox</span><span class="p">()</span>
<span class="n">y</span> <span class="o">=</span> <span class="n">y2</span> <span class="o">-</span> <span class="n">y1</span> <span class="o">+</span> <span class="mi">10</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">coords</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_titlebar</span><span class="p">,</span> <span class="o">-</span><span class="mi">5000</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">5000</span><span class="p">,</span> <span class="n">y</span> <span class="o">-</span> <span class="mi">4</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">coords</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_exprline</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">y</span> <span class="o">*</span> <span class="mi">2</span> <span class="o">-</span> <span class="mi">10</span><span class="p">,</span> <span class="mi">5000</span><span class="p">,</span> <span class="n">y</span> <span class="o">*</span> <span class="mi">2</span> <span class="o">-</span> <span class="mi">10</span><span class="p">)</span>
<span class="c1"># Position the titlebar labels..</span>
<span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="o">.</span><span class="n">bbox</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">5</span> <span class="o">-</span> <span class="n">x1</span><span class="p">,</span> <span class="mi">3</span> <span class="o">-</span> <span class="n">y1</span><span class="p">)</span>
<span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span><span class="o">.</span><span class="n">bbox</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">cx2</span> <span class="o">-</span> <span class="n">x2</span> <span class="o">-</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">3</span> <span class="o">-</span> <span class="n">y1</span><span class="p">)</span>
<span class="c1"># Draw the stack.</span>
<span class="n">stackx</span> <span class="o">=</span> <span class="mi">5</span>
<span class="k">for</span> <span class="n">tok</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">stack</span><span class="p">():</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">tok</span><span class="p">,</span> <span class="n">Tree</span><span class="p">):</span>
<span class="n">attribs</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">"tree_color"</span><span class="p">:</span> <span class="s2">"#4080a0"</span><span class="p">,</span>
<span class="s2">"tree_width"</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span>
<span class="s2">"node_font"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span><span class="p">,</span>
<span class="s2">"node_color"</span><span class="p">:</span> <span class="s2">"#006060"</span><span class="p">,</span>
<span class="s2">"leaf_color"</span><span class="p">:</span> <span class="s2">"#006060"</span><span class="p">,</span>
<span class="s2">"leaf_font"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">,</span>
<span class="p">}</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">tree_to_treesegment</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span> <span class="n">tok</span><span class="p">,</span> <span class="o">**</span><span class="n">attribs</span><span class="p">)</span>
<span class="n">widget</span><span class="o">.</span><span class="n">label</span><span class="p">()[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#000000"</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">TextWidget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span> <span class="n">tok</span><span class="p">,</span> <span class="n">color</span><span class="o">=</span><span class="s2">"#000000"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">)</span>
<span class="n">widget</span><span class="o">.</span><span class="n">bind_click</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_popup_reduce</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="n">stackx</span><span class="p">,</span> <span class="n">y</span><span class="p">)</span>
<span class="n">stackx</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span>
<span class="c1"># Draw the remaining text.</span>
<span class="n">rtextwidth</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">for</span> <span class="n">tok</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">remaining_text</span><span class="p">():</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">TextWidget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span> <span class="n">tok</span><span class="p">,</span> <span class="n">color</span><span class="o">=</span><span class="s2">"#000000"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="n">rtextwidth</span><span class="p">,</span> <span class="n">y</span><span class="p">)</span>
<span class="n">rtextwidth</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">4</span>
<span class="c1"># Allow enough room to shift the next token (for animations)</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">)</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="n">stackx</span> <span class="o">+=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">width</span><span class="p">()</span>
<span class="c1"># Move the remaining text to the correct location (keep it</span>
<span class="c1"># right-justified, when possible); and move the remaining text</span>
<span class="c1"># label, if necessary.</span>
<span class="n">stackx</span> <span class="o">=</span> <span class="nb">max</span><span class="p">(</span><span class="n">stackx</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="o">.</span><span class="n">width</span><span class="p">()</span> <span class="o">+</span> <span class="mi">25</span><span class="p">)</span>
<span class="n">rlabelwidth</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span><span class="o">.</span><span class="n">width</span><span class="p">()</span> <span class="o">+</span> <span class="mi">10</span>
<span class="k">if</span> <span class="n">stackx</span> <span class="o">>=</span> <span class="n">cx2</span> <span class="o">-</span> <span class="nb">max</span><span class="p">(</span><span class="n">rtextwidth</span><span class="p">,</span> <span class="n">rlabelwidth</span><span class="p">):</span>
<span class="n">cx2</span> <span class="o">=</span> <span class="n">stackx</span> <span class="o">+</span> <span class="nb">max</span><span class="p">(</span><span class="n">rtextwidth</span><span class="p">,</span> <span class="n">rlabelwidth</span><span class="p">)</span>
<span class="k">for</span> <span class="n">rtextwidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">:</span>
<span class="n">rtextwidget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">4</span> <span class="o">+</span> <span class="n">cx2</span> <span class="o">-</span> <span class="n">rtextwidth</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">cx2</span> <span class="o">-</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextlabel</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">-</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="n">midx</span> <span class="o">=</span> <span class="p">(</span><span class="n">stackx</span> <span class="o">+</span> <span class="n">cx2</span> <span class="o">-</span> <span class="nb">max</span><span class="p">(</span><span class="n">rtextwidth</span><span class="p">,</span> <span class="n">rlabelwidth</span><span class="p">))</span> <span class="o">/</span> <span class="mi">2</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">coords</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_stacktop</span><span class="p">,</span> <span class="n">midx</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">midx</span><span class="p">,</span> <span class="mi">5000</span><span class="p">)</span>
<span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="o">.</span><span class="n">bbox</span><span class="p">()</span>
<span class="c1"># Set up binding to allow them to shift a token by dragging it.</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">)</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="k">def</span> <span class="nf">drag_shift</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="n">midx</span><span class="o">=</span><span class="n">midx</span><span class="p">,</span> <span class="bp">self</span><span class="o">=</span><span class="bp">self</span><span class="p">):</span>
<span class="k">if</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span> <span class="o"><</span> <span class="n">midx</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">bind_drag</span><span class="p">(</span><span class="n">drag_shift</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">bind_click</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">)</span>
<span class="c1"># Draw the stack top.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_productions</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_draw_stack_top</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">widget</span><span class="p">):</span>
<span class="c1"># hack..</span>
<span class="n">midx</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">50</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">coords</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_stacktop</span><span class="p">,</span> <span class="n">midx</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">midx</span><span class="p">,</span> <span class="mi">5000</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_highlight_productions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># Highlight the productions that can be reduced.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_clear</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="k">for</span> <span class="n">prod</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">reducible_productions</span><span class="p">():</span>
<span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="n">prod</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_set</span><span class="p">(</span><span class="n">index</span><span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Button Callbacks</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">destroy</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_top</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">return</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">destroy</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">def</span> <span class="nf">reset</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">initialize</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sent</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Reset App"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">step</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">():</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">elif</span> <span class="bp">self</span><span class="o">.</span><span class="n">shift</span><span class="p">():</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">if</span> <span class="nb">list</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">parses</span><span class="p">()):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Finished:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Success"</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Finished:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Failure"</span>
<span class="k">def</span> <span class="nf">shift</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">shift</span><span class="p">():</span>
<span class="n">tok</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">stack</span><span class="p">()[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Shift:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"</span><span class="si">%r</span><span class="s2">"</span> <span class="o">%</span> <span class="n">tok</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="o">.</span><span class="n">get</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_shift</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">return</span> <span class="kc">False</span>
<span class="k">def</span> <span class="nf">reduce</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="n">production</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">reduce</span><span class="p">()</span>
<span class="k">if</span> <span class="n">production</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Reduce:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"</span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">production</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="o">.</span><span class="n">get</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_reduce</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">return</span> <span class="n">production</span>
<span class="k">def</span> <span class="nf">undo</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">undo</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">postscript</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">print_to_file</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">mainloop</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Enter the Tkinter mainloop. This function must be called if</span>
<span class="sd"> this demo is created from a non-interactive program (e.g.</span>
<span class="sd"> from a secript); otherwise, the demo will close as soon as</span>
<span class="sd"> the script completes.</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="n">in_idle</span><span class="p">():</span>
<span class="k">return</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">mainloop</span><span class="p">(</span><span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Menubar callbacks</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">resize</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="k">if</span> <span class="n">size</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="n">size</span><span class="p">)</span>
<span class="n">size</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="c1"># self._stacklabel['font'] = ('helvetica', -size-4, 'bold')</span>
<span class="c1"># self._rtextlabel['font'] = ('helvetica', -size-4, 'bold')</span>
<span class="c1"># self._lastoper_label['font'] = ('helvetica', -size)</span>
<span class="c1"># self._lastoper1['font'] = ('helvetica', -size)</span>
<span class="c1"># self._lastoper2['font'] = ('helvetica', -size)</span>
<span class="c1"># self._prodlist['font'] = ('helvetica', -size)</span>
<span class="c1"># self._prodlist_label['font'] = ('helvetica', -size-2, 'bold')</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">help</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="c1"># The default font's not very legible; try using 'fixed' instead.</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">ShowText</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span>
<span class="s2">"Help: Shift-Reduce Parser Application"</span><span class="p">,</span>
<span class="p">(</span><span class="vm">__doc__</span> <span class="ow">or</span> <span class="s2">""</span><span class="p">)</span><span class="o">.</span><span class="n">strip</span><span class="p">(),</span>
<span class="n">width</span><span class="o">=</span><span class="mi">75</span><span class="p">,</span>
<span class="n">font</span><span class="o">=</span><span class="s2">"fixed"</span><span class="p">,</span>
<span class="p">)</span>
<span class="k">except</span><span class="p">:</span>
<span class="n">ShowText</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span>
<span class="s2">"Help: Shift-Reduce Parser Application"</span><span class="p">,</span>
<span class="p">(</span><span class="vm">__doc__</span> <span class="ow">or</span> <span class="s2">""</span><span class="p">)</span><span class="o">.</span><span class="n">strip</span><span class="p">(),</span>
<span class="n">width</span><span class="o">=</span><span class="mi">75</span><span class="p">,</span>
<span class="p">)</span>
<span class="k">def</span> <span class="nf">about</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="n">ABOUT</span> <span class="o">=</span> <span class="s2">"NLTK Shift-Reduce Parser Application</span><span class="se">\n</span><span class="s2">"</span> <span class="o">+</span> <span class="s2">"Written by Edward Loper"</span>
<span class="n">TITLE</span> <span class="o">=</span> <span class="s2">"About: Shift-Reduce Parser Application"</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">from</span> <span class="nn">tkinter.messagebox</span> <span class="kn">import</span> <span class="n">Message</span>
<span class="n">Message</span><span class="p">(</span><span class="n">message</span><span class="o">=</span><span class="n">ABOUT</span><span class="p">,</span> <span class="n">title</span><span class="o">=</span><span class="n">TITLE</span><span class="p">)</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
<span class="k">except</span><span class="p">:</span>
<span class="n">ShowText</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span> <span class="n">TITLE</span><span class="p">,</span> <span class="n">ABOUT</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">edit_grammar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="n">CFGEditor</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">grammar</span><span class="p">(),</span> <span class="bp">self</span><span class="o">.</span><span class="n">set_grammar</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">set_grammar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">grammar</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">set_grammar</span><span class="p">(</span><span class="n">grammar</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_productions</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">grammar</span><span class="o">.</span><span class="n">productions</span><span class="p">())</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">delete</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="k">for</span> <span class="n">production</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="s2">"end"</span><span class="p">,</span> <span class="p">(</span><span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">production</span><span class="p">))</span>
<span class="k">def</span> <span class="nf">edit_sentence</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="n">sentence</span> <span class="o">=</span> <span class="s2">" "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sent</span><span class="p">)</span>
<span class="n">title</span> <span class="o">=</span> <span class="s2">"Edit Text"</span>
<span class="n">instr</span> <span class="o">=</span> <span class="s2">"Enter a new sentence to parse."</span>
<span class="n">EntryDialog</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span> <span class="n">sentence</span><span class="p">,</span> <span class="n">instr</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">set_sentence</span><span class="p">,</span> <span class="n">title</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">set_sentence</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">sent</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sent</span> <span class="o">=</span> <span class="n">sent</span><span class="o">.</span><span class="n">split</span><span class="p">()</span> <span class="c1"># [XX] use tagged?</span>
<span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">()</span>
<span class="c1">#########################################</span>
<span class="c1">## Reduce Production Selection</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_toggle_grammar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span><span class="o">.</span><span class="n">get</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span>
<span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span> <span class="n">after</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_feedbackframe</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Show Grammar"</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="o">.</span><span class="n">pack_forget</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Hide Grammar"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="k">def</span> <span class="nf">_prodlist_select</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">event</span><span class="p">):</span>
<span class="n">selection</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">curselection</span><span class="p">()</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">selection</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span>
<span class="k">return</span>
<span class="n">index</span> <span class="o">=</span> <span class="nb">int</span><span class="p">(</span><span class="n">selection</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="n">production</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">reduce</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">[</span><span class="n">index</span><span class="p">])</span>
<span class="k">if</span> <span class="n">production</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Reduce:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"</span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">production</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="o">.</span><span class="n">get</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_reduce</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># Reset the production selections.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_clear</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="k">for</span> <span class="n">prod</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">reducible_productions</span><span class="p">():</span>
<span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="n">prod</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_set</span><span class="p">(</span><span class="n">index</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_popup_reduce</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">widget</span><span class="p">):</span>
<span class="c1"># Remove old commands.</span>
<span class="n">productions</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">reducible_productions</span><span class="p">()</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">productions</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
<span class="k">return</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_reduce_menu</span><span class="o">.</span><span class="n">delete</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="k">for</span> <span class="n">production</span> <span class="ow">in</span> <span class="n">productions</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_reduce_menu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="nb">str</span><span class="p">(</span><span class="n">production</span><span class="p">),</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reduce</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_reduce_menu</span><span class="o">.</span><span class="n">post</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">winfo_pointerx</span><span class="p">(),</span> <span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">winfo_pointery</span><span class="p">()</span>
<span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Animations</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_animate_shift</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># What widget are we shifting?</span>
<span class="n">widget</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="c1"># Where are we shifting from & to?</span>
<span class="n">right</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
<span class="n">left</span> <span class="o">=</span> <span class="mi">5</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">left</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span>
<span class="c1"># Start animating.</span>
<span class="n">dt</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="o">.</span><span class="n">get</span><span class="p">()</span>
<span class="n">dx</span> <span class="o">=</span> <span class="p">(</span><span class="n">left</span> <span class="o">-</span> <span class="n">right</span><span class="p">)</span> <span class="o">*</span> <span class="mf">1.0</span> <span class="o">/</span> <span class="n">dt</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_shift_frame</span><span class="p">(</span><span class="n">dt</span><span class="p">,</span> <span class="n">widget</span><span class="p">,</span> <span class="n">dx</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_animate_shift_frame</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">frame</span><span class="p">,</span> <span class="n">widget</span><span class="p">,</span> <span class="n">dx</span><span class="p">):</span>
<span class="k">if</span> <span class="n">frame</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">1</span>
<span class="n">widget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">dx</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">after</span><span class="p">(</span><span class="mi">10</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate_shift_frame</span><span class="p">,</span> <span class="n">frame</span> <span class="o">-</span> <span class="mi">1</span><span class="p">,</span> <span class="n">widget</span><span class="p">,</span> <span class="n">dx</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># but: stacktop??</span>
<span class="c1"># Shift the widget to the stack.</span>
<span class="k">del</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rtextwidgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">0</span>
<span class="c1"># Display the available productions.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_draw_stack_top</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_productions</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_animate_reduce</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># What widgets are we shifting?</span>
<span class="n">numwidgets</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">stack</span><span class="p">()[</span><span class="o">-</span><span class="mi">1</span><span class="p">])</span> <span class="c1"># number of children</span>
<span class="n">widgets</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">[</span><span class="o">-</span><span class="n">numwidgets</span><span class="p">:]</span>
<span class="c1"># How far are we moving?</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">widgets</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="n">TreeSegmentWidget</span><span class="p">):</span>
<span class="n">ydist</span> <span class="o">=</span> <span class="mi">15</span> <span class="o">+</span> <span class="n">widgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">label</span><span class="p">()</span><span class="o">.</span><span class="n">height</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">ydist</span> <span class="o">=</span> <span class="mi">15</span> <span class="o">+</span> <span class="n">widgets</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">height</span><span class="p">()</span>
<span class="c1"># Start animating.</span>
<span class="n">dt</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate</span><span class="o">.</span><span class="n">get</span><span class="p">()</span>
<span class="n">dy</span> <span class="o">=</span> <span class="n">ydist</span> <span class="o">*</span> <span class="mf">2.0</span> <span class="o">/</span> <span class="n">dt</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_reduce_frame</span><span class="p">(</span><span class="n">dt</span> <span class="o">/</span> <span class="mi">2</span><span class="p">,</span> <span class="n">widgets</span><span class="p">,</span> <span class="n">dy</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_animate_reduce_frame</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">frame</span><span class="p">,</span> <span class="n">widgets</span><span class="p">,</span> <span class="n">dy</span><span class="p">):</span>
<span class="k">if</span> <span class="n">frame</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">1</span>
<span class="k">for</span> <span class="n">widget</span> <span class="ow">in</span> <span class="n">widgets</span><span class="p">:</span>
<span class="n">widget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">dy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">after</span><span class="p">(</span><span class="mi">10</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animate_reduce_frame</span><span class="p">,</span> <span class="n">frame</span> <span class="o">-</span> <span class="mi">1</span><span class="p">,</span> <span class="n">widgets</span><span class="p">,</span> <span class="n">dy</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">del</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">[</span><span class="o">-</span><span class="nb">len</span><span class="p">(</span><span class="n">widgets</span><span class="p">)</span> <span class="p">:]</span>
<span class="k">for</span> <span class="n">widget</span> <span class="ow">in</span> <span class="n">widgets</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">remove_widget</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="n">tok</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">stack</span><span class="p">()[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">tok</span><span class="p">,</span> <span class="n">Tree</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">()</span>
<span class="n">label</span> <span class="o">=</span> <span class="n">TextWidget</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span> <span class="nb">str</span><span class="p">(</span><span class="n">tok</span><span class="o">.</span><span class="n">label</span><span class="p">()),</span> <span class="n">color</span><span class="o">=</span><span class="s2">"#006060"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span>
<span class="p">)</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">TreeSegmentWidget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span> <span class="n">label</span><span class="p">,</span> <span class="n">widgets</span><span class="p">,</span> <span class="n">width</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stacklabel</span><span class="o">.</span><span class="n">bbox</span><span class="p">()</span>
<span class="n">y</span> <span class="o">=</span> <span class="n">y2</span> <span class="o">-</span> <span class="n">y1</span> <span class="o">+</span> <span class="mi">10</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">:</span>
<span class="n">x</span> <span class="o">=</span> <span class="mi">5</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">x</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="n">x</span><span class="p">,</span> <span class="n">y</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="c1"># Display the available productions.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_draw_stack_top</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_productions</span><span class="p">()</span>
<span class="c1"># # Delete the old widgets..</span>
<span class="c1"># del self._stackwidgets[-len(widgets):]</span>
<span class="c1"># for widget in widgets:</span>
<span class="c1"># self._cframe.destroy_widget(widget)</span>
<span class="c1">#</span>
<span class="c1"># # Make a new one.</span>
<span class="c1"># tok = self._parser.stack()[-1]</span>
<span class="c1"># if isinstance(tok, Tree):</span>
<span class="c1"># attribs = {'tree_color': '#4080a0', 'tree_width': 2,</span>
<span class="c1"># 'node_font': bold, 'node_color': '#006060',</span>
<span class="c1"># 'leaf_color': '#006060', 'leaf_font':self._font}</span>
<span class="c1"># widget = tree_to_treesegment(self._canvas, tok.type(),</span>
<span class="c1"># **attribs)</span>
<span class="c1"># widget.node()['color'] = '#000000'</span>
<span class="c1"># else:</span>
<span class="c1"># widget = TextWidget(self._canvas, tok.type(),</span>
<span class="c1"># color='#000000', font=self._font)</span>
<span class="c1"># widget.bind_click(self._popup_reduce)</span>
<span class="c1"># (x1, y1, x2, y2) = self._stacklabel.bbox()</span>
<span class="c1"># y = y2-y1+10</span>
<span class="c1"># if not self._stackwidgets: x = 5</span>
<span class="c1"># else: x = self._stackwidgets[-1].bbox()[2] + 10</span>
<span class="c1"># self._cframe.add_widget(widget, x, y)</span>
<span class="c1"># self._stackwidgets.append(widget)</span>
<span class="c1"># self._redraw()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">0</span>
<span class="c1">#########################################</span>
<span class="c1">## Hovering.</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_highlight_hover</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">event</span><span class="p">):</span>
<span class="c1"># What production are we hovering over?</span>
<span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">nearest</span><span class="p">(</span><span class="n">event</span><span class="o">.</span><span class="n">y</span><span class="p">)</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_hover</span> <span class="o">==</span> <span class="n">index</span><span class="p">:</span>
<span class="k">return</span>
<span class="c1"># Clear any previous hover highlighting.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_clear_hover</span><span class="p">()</span>
<span class="c1"># If the production corresponds to an available reduction,</span>
<span class="c1"># highlight the stack.</span>
<span class="n">selection</span> <span class="o">=</span> <span class="p">[</span><span class="nb">int</span><span class="p">(</span><span class="n">s</span><span class="p">)</span> <span class="k">for</span> <span class="n">s</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">curselection</span><span class="p">()]</span>
<span class="k">if</span> <span class="n">index</span> <span class="ow">in</span> <span class="n">selection</span><span class="p">:</span>
<span class="n">rhslen</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">.</span><span class="n">rhs</span><span class="p">())</span>
<span class="k">for</span> <span class="n">stackwidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">[</span><span class="o">-</span><span class="n">rhslen</span><span class="p">:]:</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">stackwidget</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">):</span>
<span class="n">stackwidget</span><span class="o">.</span><span class="n">label</span><span class="p">()[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#00a000"</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">stackwidget</span><span class="p">[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#00a000"</span>
<span class="c1"># Remember what production we're hovering over.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_hover</span> <span class="o">=</span> <span class="n">index</span>
<span class="k">def</span> <span class="nf">_clear_hover</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">event</span><span class="p">):</span>
<span class="c1"># Clear any previous hover highlighting.</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_hover</span> <span class="o">==</span> <span class="o">-</span><span class="mi">1</span><span class="p">:</span>
<span class="k">return</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_hover</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="k">for</span> <span class="n">stackwidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_stackwidgets</span><span class="p">:</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">stackwidget</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">):</span>
<span class="n">stackwidget</span><span class="o">.</span><span class="n">label</span><span class="p">()[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"black"</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">stackwidget</span><span class="p">[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"black"</span>
<div class="viewcode-block" id="app"><a class="viewcode-back" href="../../../api/nltk.app.srparser_app.html#nltk.app.srparser_app.app">[docs]</a><span class="k">def</span> <span class="nf">app</span><span class="p">():</span>
<span class="sd">"""</span>
<span class="sd"> Create a shift reduce parser app, using a simple grammar and</span>
<span class="sd"> text.</span>
<span class="sd"> """</span>
<span class="kn">from</span> <span class="nn">nltk.grammar</span> <span class="kn">import</span> <span class="n">CFG</span><span class="p">,</span> <span class="n">Nonterminal</span><span class="p">,</span> <span class="n">Production</span>
<span class="n">nonterminals</span> <span class="o">=</span> <span class="s2">"S VP NP PP P N Name V Det"</span>
<span class="p">(</span><span class="n">S</span><span class="p">,</span> <span class="n">VP</span><span class="p">,</span> <span class="n">NP</span><span class="p">,</span> <span class="n">PP</span><span class="p">,</span> <span class="n">P</span><span class="p">,</span> <span class="n">N</span><span class="p">,</span> <span class="n">Name</span><span class="p">,</span> <span class="n">V</span><span class="p">,</span> <span class="n">Det</span><span class="p">)</span> <span class="o">=</span> <span class="p">(</span><span class="n">Nonterminal</span><span class="p">(</span><span class="n">s</span><span class="p">)</span> <span class="k">for</span> <span class="n">s</span> <span class="ow">in</span> <span class="n">nonterminals</span><span class="o">.</span><span class="n">split</span><span class="p">())</span>