Docstring clarifications

sphinx/addnodes.py

@@ -2,7 +2,7 @@
     sphinx.addnodes
     ~~~~~~~~~~~~~~~
 
-    Additional docutils nodes.
+    Document tree nodes that Sphinx defines on top of those in Docutils.
 
     :copyright: Copyright 2007-2021 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
@@ -120,7 +120,7 @@ def extract_original_messages(self) -> List[str]:
 #############################################################
 
 class _desc_classes_injector(nodes.Element, not_smartquotable):
-    """Helper base class for injecting a fixes list of classes.
+    """Helper base class for injecting a fixed list of classes.
 
     Use as the first base class.
     """
@@ -391,7 +391,7 @@ class index(nodes.Invisible, nodes.Inline, nodes.TextElement):
 
 
 class centered(nodes.Part, nodes.TextElement):
-    """Deprecated."""
+    """This node is deprecated."""
 
 
 class acks(nodes.Element):
@@ -456,13 +456,18 @@ class pending_xref(nodes.Inline, nodes.Element):
 
 
 class pending_xref_condition(nodes.Inline, nodes.TextElement):
-    """Node for cross-references that are used to choose appropriate
-    content of the reference by conditions on the resolving phase.
+    """Node representing a potential way to create a cross-reference and the
+    condition in which this way should be used.
 
-    When the :py:class:`pending_xref` node contains one or more
-    **pending_xref_condition** nodes, the cross-reference resolver
-    should choose the content of the reference using defined conditions
-    in ``condition`` attribute of each pending_xref_condition nodes::
+    This node is only allowed to be placed under a :py:class:`pending_xref`
+    node.  A **pending_xref** node must contain either no **pending_xref_condition**
+    nodes or it must only contains **pending_xref_condition** nodes.
+
+    The cross-reference resolver will replace a :py:class:`pending_xref` which
+    contains **pending_xref_condition** nodes by the content of exactly one of
+    those **pending_xref_condition** nodes' content. It uses the **condition**
+    attribute to decide which **pending_xref_condition** node's content to
+    use. For example, let us consider how the cross-reference resolver acts on::
 
         <pending_xref refdomain="py" reftarget="io.StringIO ...>
             <pending_xref_condition condition="resolved">
@@ -472,32 +477,26 @@ class pending_xref_condition(nodes.Inline, nodes.TextElement):
                 <literal>
                     io.StringIO
 
-    After the processing of cross-reference resolver, one of the content node
-    under pending_xref_condition node is chosen by its condition and to be
-    removed all of pending_xref_condition nodes::
+    If the cross-reference resolver successfully resolves the cross-reference,
+    then it rewrites the **pending_xref** as::
 
-        # When resolved the cross-reference successfully
         <reference>
             <literal>
                 StringIO
 
-        # When resolution is failed
+    Otherwise, if the cross-reference resolution failed, it rewrites the
+    **pending_xref** as::
+
         <reference>
             <literal>
                 io.StringIO
 
-    .. note:: This node is only allowed to be placed under pending_xref node.
-              It is not allows to place it under other nodes.  In addition,
-              pending_xref node must contain only pending_xref_condition
-              nodes if it contains one or more pending_xref_condition nodes.
-
-    The pending_xref_condition node should have **condition** attribute.
+    The **pending_xref_condition** node should have **condition** attribute.
     Domains can be store their individual conditions into the attribute to
     filter contents on resolving phase.  As a reserved condition name,
     ``condition="*"`` is used for the fallback of resolution failure.
     Additionally, as a recommended condition name, ``condition="resolved"``
-    is used for the representation of resolstion success in the intersphinx
-    module.
+    represents a resolution success in the intersphinx module.
 
     .. versionadded:: 4.0
     """

sphinx/application.py

@@ -632,8 +632,9 @@ def add_directive(self, name: str, cls: Type[Directive], override: bool = False)
 
         :param name: The name of the directive
         :param cls: A directive class
-        :param override: If true, install the directive forcedly even if another directive
+        :param override: If false, do not install it if another directive
                          is already installed as the same name
+                         If true, unconditionally install the directive.
 
         For example, a custom directive named ``my-directive`` would be added
         like this:
@@ -680,8 +681,9 @@ def add_role(self, name: str, role: Any, override: bool = False) -> None:
 
         :param name: The name of role
         :param role: A role function
-        :param override: If true, install the role forcedly even if another role is already
-                         installed as the same name
+        :param override: If false, do not install it if another role
+                         is already installed as the same name
+                         If true, unconditionally install the role.
 
         For more details about role functions, see `the Docutils docs
         <https://docutils.sourceforge.io/docs/howto/rst-roles.html>`__ .
@@ -701,8 +703,9 @@ def add_generic_role(self, name: str, nodeclass: Any, override: bool = False) ->
         Register a Docutils role that does nothing but wrap its contents in the
         node given by *nodeclass*.
 
-        If *override* is True, the given *nodeclass* is forcedly installed even if
-        a role named as *name* is already installed.
+        :param override: If false, do not install it if another role
+                         is already installed as the same name
+                         If true, unconditionally install the role.
 
         .. versionadded:: 0.6
         .. versionchanged:: 1.8
@@ -721,8 +724,9 @@ def add_domain(self, domain: Type[Domain], override: bool = False) -> None:
         """Register a domain.
 
         :param domain: A domain class
-        :param override: If true, install the domain forcedly even if another domain
+        :param override: If false, do not install it if another domain
                          is already installed as the same name
+                         If true, unconditionally install the domain.
 
         .. versionadded:: 1.0
         .. versionchanged:: 1.8
@@ -740,8 +744,9 @@ def add_directive_to_domain(self, domain: str, name: str,
         :param domain: The name of target domain
         :param name: A name of directive
         :param cls: A directive class
-        :param override: If true, install the directive forcedly even if another directive
+        :param override: If false, do not install it if another directive
                          is already installed as the same name
+                         If true, unconditionally install the directive.
 
         .. versionadded:: 1.0
         .. versionchanged:: 1.8
@@ -759,8 +764,9 @@ def add_role_to_domain(self, domain: str, name: str, role: Union[RoleFunction, X
         :param domain: The name of the target domain
         :param name: The name of the role
         :param role: The role function
-        :param override: If true, install the role forcedly even if another role is already
-                         installed as the same name
+        :param override: If false, do not install it if another role
+                         is already installed as the same name
+                         If true, unconditionally install the role.
 
         .. versionadded:: 1.0
         .. versionchanged:: 1.8
@@ -776,8 +782,9 @@ def add_index_to_domain(self, domain: str, index: Type[Index], override: bool =
 
         :param domain: The name of the target domain
         :param index: The index class
-        :param override: If true, install the index forcedly even if another index is
-                         already installed as the same name
+        :param override: If false, do not install it if another index
+                         is already installed as the same name
+                         If true, unconditionally install the index.
 
         .. versionadded:: 1.0
         .. versionchanged:: 1.8
@@ -881,8 +888,10 @@ def add_crossref_type(self, directivename: str, rolename: str, indextemplate: st
         (Of course, the element following the ``topic`` directive needn't be a
         section.)
 
-        If *override* is True, the given crossref_type is forcedly installed even if
-        a crossref_type having the same name is already installed.
+
+        :param override: If false, do not install it if another cross-reference type
+                         is already installed as the same name
+                         If true, unconditionally install the cross-reference type.
 
         .. versionchanged:: 1.8
            Add *override* keyword.
@@ -937,17 +946,19 @@ def add_post_transform(self, transform: Type[Transform]) -> None:
         """
         self.registry.add_post_transform(transform)
 
-    def add_js_file(self, filename: str, priority: int = 500, **kwargs: Any) -> None:
+    def add_js_file(self, filename: Optional[str], priority: int = 500, **kwargs: Any) -> None:
         """Register a JavaScript file to include in the HTML output.
 
-        Add *filename* to the list of JavaScript files that the default HTML
-        template will include in order of *priority* (ascending).  The filename
-        must be relative to the HTML static path , or a full URI with scheme.
-        If the priority of the JavaScript file is the same as others, the JavaScript
-        files will be included in order of registration.  If the keyword
-        argument ``body`` is given, its value will be added between the
-        ``<script>`` tags. Extra keyword arguments are included as attributes of
-        the ``<script>`` tag.
+        :param filename: The name of a file that the default HTML
+                         template will include. It must be relative to the HTML
+                         static path, or a full URI with scheme.
+        :param priority: Files are included in ascending order of priority. If
+                         multiple JavaScript files have the same priority,
+                         those files will be included in order of registration.
+        :param kwargs:   If the keyword argument ``body`` is given, its value will
+                         be added between the ``<script>`` tags.
+                         Extra keyword arguments are included as attributes of
+                         the ``<script>`` tag.
 
         Example::
 
@@ -991,12 +1002,14 @@ def add_js_file(self, filename: str, priority: int = 500, **kwargs: Any) -> None
     def add_css_file(self, filename: str, priority: int = 500, **kwargs: Any) -> None:
         """Register a stylesheet to include in the HTML output.
 
-        Add *filename* to the list of CSS files that the default HTML template
-        will include in order of *priority* (ascending).  The filename must be
-        relative to the HTML static path, or a full URI with scheme.  If the
-        priority of the CSS file is the same as others, the CSS files will be
-        included in order of registration.  The keyword arguments are also
-        accepted for attributes of ``<link>`` tag.
+        :param filename: The name of a CSS file that the default HTML
+                         template will include. It must be relative to the HTML
+                         static path, or a full URI with scheme.
+        :param priority: Files are included in ascending order of priority. If
+                         multiple CSS files have the same priority,
+                         those files will be included in order of registration.
+        :param kwargs:   The keyword arguments are also accepted for attributes of
+                         ``<link>`` tag.
 
         Example::
 
@@ -1163,8 +1176,9 @@ def add_source_suffix(self, suffix: str, filetype: str, override: bool = False)
         Same as :confval:`source_suffix`.  The users can override this
         using the config setting.
 
-        If *override* is True, the given *suffix* is forcedly installed even if
-        the same suffix is already installed.
+        :param override: If false, do not install it the same suffix
+                         is already installed.
+                         If true, unconditionally install the suffix.
 
         .. versionadded:: 1.8
         """
@@ -1173,8 +1187,9 @@ def add_source_suffix(self, suffix: str, filetype: str, override: bool = False)
     def add_source_parser(self, parser: Type[Parser], override: bool = False) -> None:
         """Register a parser class.
 
-        If *override* is True, the given *parser* is forcedly installed even if
-        a parser for the same suffix is already installed.
+        :param override: If false, do not install it if another parser
+                         is already installed for the same suffix.
+                         If true, unconditionally install the parser.
 
         .. versionadded:: 1.4
         .. versionchanged:: 1.8

sphinx/builders/latex/transforms.py

@@ -38,7 +38,7 @@ def apply(self, **kwargs: Any) -> None:
 
 
 class SubstitutionDefinitionsRemover(SphinxPostTransform):
-    """Remove ``substitution_definition node from doctrees."""
+    """Remove ``substitution_definition`` node from doctrees."""
 
     # should be invoked after Substitutions process
     default_priority = Substitutions.default_priority + 1

sphinx/domains/std.py

@@ -493,12 +493,12 @@ def run(self) -> List[Node]:
         lines = nl_escape_re.sub('', self.arguments[0]).split('\n')
 
         productionGroup = ""
-        i = 0
+        first_rule_seen = False
         for rule in lines:
-            if i == 0 and ':' not in rule:
+            if not first_rule_seen and ':' not in rule:
                 productionGroup = rule.strip()
                 continue
-            i += 1
+            first_rule_seen = True
             try:
                 name, tokens = rule.split(':', 1)
             except ValueError:

sphinx/extension.py

@@ -42,7 +42,14 @@ def __init__(self, name: str, module: Any, **kwargs: Any) -> None:
 
 
 def verify_needs_extensions(app: "Sphinx", config: Config) -> None:
-    """Verify the required Sphinx extensions are loaded."""
+    """Check that extensions mentioned in :confval:`needs_extensions` satisfy the version
+    requirement, and warn if an extension is not loaded.
+
+    Warns if an extension in :confval:`needs_extension` is not loaded.
+
+    :raises VersionRequirementError: if the version of an extension in
+    :confval:`needs_extension` is unknown or older than the required version.
+    """
     if config.needs_extensions is None:
         return