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tnt.py
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tnt.py
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# -*- coding: utf-8 -*-
"""
pygments.lexers.tnt
~~~~~~~~~~~~~~~~~~~
Lexer for Typographic Number Theory.
:copyright: Copyright 2006-2020 by the Pygments team, see AUTHORS.
:license: BSD, see LICENSE for details.
"""
import re
from pygments.lexer import Lexer
from pygments.token import Text, Comment, Operator, Keyword, Name, Number, \
Punctuation, Error
__all__ = ['TNTLexer']
class TNTLexer(Lexer):
"""
Lexer for Typographic Number Theory, as described in the book
Gödel, Escher, Bach, by Douglas R. Hofstadter,
or as summarized here:
https://github.com/Kenny2github/language-tnt/blob/master/README.md#summary-of-tnt
.. versionadded:: 2.7
"""
name = 'Typographic Number Theory'
aliases = ['tnt']
filenames = ['*.tnt']
cur = []
LOGIC = set('⊃→]&∧^|∨Vv')
OPERATORS = set('+.⋅*')
VARIABLES = set('abcde')
PRIMES = set("'′")
NEGATORS = set('~!')
QUANTIFIERS = set('AE∀∃')
NUMBERS = set('0123456789')
WHITESPACE = set('\t \v\n')
RULES = re.compile('''(?xi)
joining | separation | double-tilde | fantasy\\ rule
| carry[- ]over(?:\\ of)?(?:\\ line)?\\ ([0-9]+) | detachment
| contrapositive | De\\ Morgan | switcheroo
| specification | generalization | interchange
| existence | symmetry | transitivity
| add\\ S | drop\\ S | induction
| axiom\\ ([1-5]) | premise | push | pop
''')
LINENOS = re.compile(r'(?:[0-9]+)(?:(?:, ?|,? and )(?:[0-9]+))*')
COMMENT = re.compile(r'\[[^\n\]]+\]')
def __init__(self, *args, **kwargs):
Lexer.__init__(self, *args, **kwargs)
self.cur = []
def whitespace(self, start, text, required=False):
"""Tokenize whitespace."""
end = start
try:
while text[end] in self.WHITESPACE:
end += 1
except IndexError:
end = len(text)
if required:
assert end != start
if end != start:
self.cur.append((start, Text, text[start:end]))
return end
def variable(self, start, text):
"""Tokenize a variable."""
assert text[start] in self.VARIABLES
end = start+1
while text[end] in self.PRIMES:
end += 1
self.cur.append((start, Name.Variable, text[start:end]))
return end
def term(self, start, text):
"""Tokenize a term."""
if text[start] == 'S': # S...S(...) or S...0
end = start+1
while text[end] == 'S':
end += 1
self.cur.append((start, Number.Integer, text[start:end]))
return self.term(end, text)
if text[start] == '0': # the singleton 0
self.cur.append((start, Number.Integer, text[start]))
return start+1
if text[start] in self.VARIABLES: # a''...
return self.variable(start, text)
if text[start] == '(': # (...+...)
self.cur.append((start, Punctuation, text[start]))
start = self.term(start+1, text)
assert text[start] in self.OPERATORS
self.cur.append((start, Operator, text[start]))
start = self.term(start+1, text)
assert text[start] == ')'
self.cur.append((start, Punctuation, text[start]))
return start+1
raise AssertionError # no matches
def formula(self, start, text):
"""Tokenize a formula."""
if text[start] in self.NEGATORS: # ~<...>
end = start+1
while text[end] in self.NEGATORS:
end += 1
self.cur.append((start, Operator, text[start:end]))
return self.formula(end, text)
if text[start] in self.QUANTIFIERS: # Aa:<...>
self.cur.append((start, Keyword.Declaration, text[start]))
start = self.variable(start+1, text)
assert text[start] == ':'
self.cur.append((start, Punctuation, text[start]))
return self.formula(start+1, text)
if text[start] == '<': # <...&...>
self.cur.append((start, Punctuation, text[start]))
start = self.formula(start+1, text)
assert text[start] in self.LOGIC
self.cur.append((start, Operator, text[start]))
start = self.formula(start+1, text)
assert text[start] == '>'
self.cur.append((start, Punctuation, text[start]))
return start+1
# ...=...
start = self.term(start, text)
assert text[start] == '='
self.cur.append((start, Operator, text[start]))
start = self.term(start+1, text)
return start
def rule(self, start, text):
"""Tokenize a rule."""
match = self.RULES.match(text, start)
assert match is not None
groups = sorted(match.regs[1:]) # exclude whole match
for group in groups:
if group[0] >= 0: # this group matched
self.cur.append((start, Keyword, text[start:group[0]]))
self.cur.append((group[0], Number.Integer,
text[group[0]:group[1]]))
if group[1] != match.end():
self.cur.append((group[1], Keyword,
text[group[1]:match.end()]))
break
else:
self.cur.append((start, Keyword, text[start:match.end()]))
return match.end()
def lineno(self, start, text):
"""Tokenize a line referral."""
end = start
while text[end] not in self.NUMBERS:
end += 1
self.cur.append((start, Punctuation, text[start]))
self.cur.append((start+1, Text, text[start+1:end]))
start = end
match = self.LINENOS.match(text, start)
assert match is not None
assert text[match.end()] == ')'
self.cur.append((match.start(), Number.Integer, match.group(0)))
self.cur.append((match.end(), Punctuation, text[match.end()]))
return match.end() + 1
def error_till_line_end(self, start, text):
"""Mark everything from ``start`` to the end of the line as Error."""
end = start
try:
while text[end] != '\n': # there's whitespace in rules
end += 1
except IndexError:
end = len(text)
if end != start:
self.cur.append((start, Error, text[start:end]))
end = self.whitespace(end, text)
return end
def get_tokens_unprocessed(self, text):
"""Returns a list of TNT tokens."""
self.cur = []
start = end = self.whitespace(0, text)
while start <= end < len(text):
try:
# try line number
while text[end] in self.NUMBERS:
end += 1
if end != start: # actual number present
self.cur.append((start, Number.Integer, text[start:end]))
# whitespace is required after a line number
orig = len(self.cur)
try:
start = end = self.whitespace(end, text, True)
except AssertionError:
del self.cur[orig:]
start = end = self.error_till_line_end(end, text)
continue
# at this point it could be a comment
match = self.COMMENT.match(text, start)
if match is not None:
self.cur.append((start, Comment, text[start:match.end()]))
start = end = match.end()
# anything after the closing bracket is invalid
start = end = self.error_till_line_end(start, text)
# do not attempt to process the rest
continue
del match
if text[start] in '[]': # fantasy push or pop
self.cur.append((start, Keyword, text[start]))
start += 1
end += 1
else:
# one formula, possibly containing subformulae
orig = len(self.cur)
try:
start = end = self.formula(start, text)
except AssertionError: # not well-formed
del self.cur[orig:]
while text[end] not in self.WHITESPACE:
end += 1
self.cur.append((start, Error, text[start:end]))
start = end
# skip whitespace after formula
orig = len(self.cur)
try:
start = end = self.whitespace(end, text, True)
except AssertionError:
del self.cur[orig:]
start = end = self.error_till_line_end(start, text)
continue
# rule proving this formula a theorem
orig = len(self.cur)
try:
start = end = self.rule(start, text)
except AssertionError:
del self.cur[orig:]
start = end = self.error_till_line_end(start, text)
continue
# skip whitespace after rule
start = end = self.whitespace(end, text)
# line marker
if text[start] == '(':
orig = len(self.cur)
try:
start = end = self.lineno(start, text)
except AssertionError:
del self.cur[orig:]
start = end = self.error_till_line_end(start, text)
continue
start = end = self.whitespace(start, text)
except IndexError:
try:
del self.cur[orig:]
except NameError:
pass # if orig was never defined, fine
self.error_till_line_end(start, text)
return self.cur