|
| 1 | +"""Support for documenting Python's grammar.""" |
| 2 | + |
| 3 | +from __future__importannotations |
| 4 | + |
| 5 | +importre |
| 6 | +fromtypingimportTYPE_CHECKING |
| 7 | + |
| 8 | +fromdocutilsimportnodes |
| 9 | +fromdocutils.parsers.rstimportdirectives |
| 10 | +fromsphinximportaddnodes |
| 11 | +fromsphinx.domains.stdimporttoken_xrefs |
| 12 | +fromsphinx.util.docutilsimportSphinxDirective |
| 13 | +fromsphinx.util.nodesimportmake_id |
| 14 | + |
| 15 | +ifTYPE_CHECKING: |
| 16 | +fromcollections.abcimportSequence |
| 17 | +fromtypingimportAny |
| 18 | + |
| 19 | +fromdocutils.nodesimportNode |
| 20 | +fromsphinx.applicationimportSphinx |
| 21 | +fromsphinx.util.typingimportExtensionMetadata |
| 22 | + |
| 23 | + |
| 24 | +classsnippet_string_node(nodes.inline):# noqa: N801 (snake_case is fine) |
| 25 | +"""Node for a string literal in a grammar snippet.""" |
| 26 | + |
| 27 | +def__init__( |
| 28 | +self, |
| 29 | +rawsource:str='', |
| 30 | +text:str='', |
| 31 | +*children:Node, |
| 32 | +**attributes:Any, |
| 33 | + )->None: |
| 34 | +super().__init__(rawsource,text,*children,**attributes) |
| 35 | +# Use the Pygments highlight class for `Literal.String.Other` |
| 36 | +self['classes'].append('sx') |
| 37 | + |
| 38 | + |
| 39 | +classGrammarSnippetBase(SphinxDirective): |
| 40 | +"""Common functionality for GrammarSnippetDirective & CompatProductionList.""" |
| 41 | + |
| 42 | +# The option/argument handling is left to the individual classes. |
| 43 | + |
| 44 | +defmake_grammar_snippet( |
| 45 | +self,options:dict[str,Any],content:Sequence[str] |
| 46 | + )->list[nodes.paragraph]: |
| 47 | +"""Create a literal block from options & content.""" |
| 48 | + |
| 49 | +group_name=options['group'] |
| 50 | + |
| 51 | +# Docutils elements have a `rawsource` attribute that is supposed to be |
| 52 | +# set to the original ReST source. |
| 53 | +# Sphinx does the following with it: |
| 54 | +# - if it's empty, set it to `self.astext()` |
| 55 | +# - if it matches `self.astext()` when generating the output, |
| 56 | +# apply syntax highlighting (which is based on the plain-text content |
| 57 | +# and thus discards internal formatting, like references). |
| 58 | +# To get around this, we set it to this non-empty string: |
| 59 | +rawsource='You should not see this.' |
| 60 | + |
| 61 | +literal=nodes.literal_block( |
| 62 | +rawsource, |
| 63 | +'', |
| 64 | +classes=['highlight'], |
| 65 | + ) |
| 66 | + |
| 67 | +grammar_re=re.compile( |
| 68 | +r""" |
| 69 | + (?P<rule_name>^[a-zA-Z0-9_]+) # identifier at start of line |
| 70 | + (?=:) # ... followed by a colon |
| 71 | + | |
| 72 | + (?P<rule_ref>`[^\s`]+`) # identifier in backquotes |
| 73 | + | |
| 74 | + (?P<single_quoted>'[^']*') # string in 'quotes' |
| 75 | + | |
| 76 | + (?P<double_quoted>"[^"]*") # string in "quotes" |
| 77 | + """, |
| 78 | +re.VERBOSE, |
| 79 | + ) |
| 80 | + |
| 81 | +forlineincontent: |
| 82 | +last_pos=0 |
| 83 | +formatchingrammar_re.finditer(line): |
| 84 | +# Handle text between matches |
| 85 | +ifmatch.start()>last_pos: |
| 86 | +literal+=nodes.Text(line[last_pos :match.start()]) |
| 87 | +last_pos=match.end() |
| 88 | + |
| 89 | +# Handle matches |
| 90 | +group_dict= { |
| 91 | +name:content |
| 92 | +forname,contentinmatch.groupdict().items() |
| 93 | +ifcontentisnotNone |
| 94 | + } |
| 95 | +matchgroup_dict: |
| 96 | +case {'rule_name':name}: |
| 97 | +literal+=self.make_link_target_for_token( |
| 98 | +group_name,name |
| 99 | + ) |
| 100 | +case {'rule_ref':ref_text}: |
| 101 | +literal+=token_xrefs(ref_text,group_name) |
| 102 | +case {'single_quoted':name}| {'double_quoted':name}: |
| 103 | +literal+=snippet_string_node('',name) |
| 104 | +case _: |
| 105 | +raiseValueError('unhandled match') |
| 106 | +literal+=nodes.Text(line[last_pos:]+'\n') |
| 107 | + |
| 108 | +node=nodes.paragraph( |
| 109 | +'', |
| 110 | +'', |
| 111 | +literal, |
| 112 | + ) |
| 113 | + |
| 114 | +return [node] |
| 115 | + |
| 116 | +defmake_link_target_for_token( |
| 117 | +self,group_name:str,name:str |
| 118 | + )->addnodes.literal_strong: |
| 119 | +"""Return a literal node which is a link target for the given token.""" |
| 120 | +name_node=addnodes.literal_strong() |
| 121 | + |
| 122 | +# Cargo-culted magic to make `name_node` a link target |
| 123 | +# similar to Sphinx `production`. |
| 124 | +# This needs to be the same as what Sphinx does |
| 125 | +# to avoid breaking existing links. |
| 126 | +domain=self.env.domains['std'] |
| 127 | +obj_name=f"{group_name}:{name}" |
| 128 | +prefix=f'grammar-token-{group_name}' |
| 129 | +node_id=make_id(self.env,self.state.document,prefix,name) |
| 130 | +name_node['ids'].append(node_id) |
| 131 | +self.state.document.note_implicit_target(name_node,name_node) |
| 132 | +domain.note_object('token',obj_name,node_id,location=name_node) |
| 133 | + |
| 134 | +text_node=nodes.Text(name) |
| 135 | +name_node+=text_node |
| 136 | +returnname_node |
| 137 | + |
| 138 | + |
| 139 | +classGrammarSnippetDirective(GrammarSnippetBase): |
| 140 | +"""Transform a grammar-snippet directive to a Sphinx literal_block |
| 141 | +
|
| 142 | + That is, turn something like: |
| 143 | +
|
| 144 | + .. grammar-snippet:: file |
| 145 | + :group: python-grammar |
| 146 | +
|
| 147 | + file: (NEWLINE | statement)* |
| 148 | +
|
| 149 | + into something similar to Sphinx productionlist, but better suited |
| 150 | + for our needs: |
| 151 | + - Instead of `::=`, use a colon, as in `Grammar/python.gram` |
| 152 | + - Show the listing almost as is, with no auto-aligment. |
| 153 | + The only special character is the backtick, which marks tokens. |
| 154 | +
|
| 155 | + Unlike Sphinx's productionlist, this directive supports options. |
| 156 | + The "group" must be given as a named option. |
| 157 | + The content must be preceded by a blank line (like with most ReST |
| 158 | + directives). |
| 159 | + """ |
| 160 | + |
| 161 | +has_content=True |
| 162 | +option_spec= { |
| 163 | +'group':directives.unchanged_required, |
| 164 | + } |
| 165 | + |
| 166 | +# We currently ignore arguments. |
| 167 | +required_arguments=0 |
| 168 | +optional_arguments=1 |
| 169 | +final_argument_whitespace=True |
| 170 | + |
| 171 | +defrun(self)->list[nodes.paragraph]: |
| 172 | +returnself.make_grammar_snippet(self.options,self.content) |
| 173 | + |
| 174 | + |
| 175 | +classCompatProductionList(GrammarSnippetBase): |
| 176 | +"""Create grammar snippets from reST productionlist syntax |
| 177 | +
|
| 178 | + This is intended to be a transitional directive, used while we switch |
| 179 | + from productionlist to grammar-snippet. |
| 180 | + It makes existing docs that use the ReST syntax look like grammar-snippet, |
| 181 | + as much as possible. |
| 182 | + """ |
| 183 | + |
| 184 | +has_content=False |
| 185 | +required_arguments=1 |
| 186 | +optional_arguments=0 |
| 187 | +final_argument_whitespace=True |
| 188 | +option_spec= {} |
| 189 | + |
| 190 | +defrun(self)->list[nodes.paragraph]: |
| 191 | +# The "content" of a productionlist is actually the first and only |
| 192 | +# argument. The first line is the group; the rest is the content lines. |
| 193 | +lines=self.arguments[0].splitlines() |
| 194 | +group=lines[0].strip() |
| 195 | +options= {'group':group} |
| 196 | +# We assume there's a colon in each line; align on it. |
| 197 | +align_column=max(line.index(':')forlineinlines[1:])+1 |
| 198 | +content= [] |
| 199 | +forlineinlines[1:]: |
| 200 | +rule_name,_colon,text=line.partition(':') |
| 201 | +rule_name=rule_name.strip() |
| 202 | +ifrule_name: |
| 203 | +name_part=rule_name+':' |
| 204 | +else: |
| 205 | +name_part='' |
| 206 | +content.append(f'{name_part:<{align_column}}{text}') |
| 207 | +returnself.make_grammar_snippet(options,content) |
| 208 | + |
| 209 | + |
| 210 | +defsetup(app:Sphinx)->ExtensionMetadata: |
| 211 | +app.add_directive('grammar-snippet',GrammarSnippetDirective) |
| 212 | +app.add_directive_to_domain( |
| 213 | +'std','productionlist',CompatProductionList,override=True |
| 214 | + ) |
| 215 | +return { |
| 216 | +'version':'1.0', |
| 217 | +'parallel_read_safe':True, |
| 218 | +'parallel_write_safe':True, |
| 219 | + } |