djavu-asus/emacs/elpy/rpc-venv/lib/python3.11/site-packages/yapf/pyparser/pyparser.py

   1 # Copyright 2022 Bill Wendling, All Rights Reserved.
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14 """Simple Python Parser
  15
  16 Parse Python code into a list of logical lines, represented by LogicalLine
  17 objects. This uses Python's tokenizer to generate the tokens. As such, YAPF must
  18 be run with the appropriate Python version---Python >=3.7 for Python 3.7 code,
  19 Python >=3.8 for Python 3.8 code, etc.
  20
  21 This parser uses Python's native "tokenizer" module to generate a list of tokens
  22 for the source code. It then uses Python's native "ast" module to assign
  23 subtypes, calculate split penalties, etc.
  24
  25 A "logical line" produced by Python's "tokenizer" module ends with a
  26 tokenize.NEWLINE, rather than a tokenize.NL, making it easy to separate them
  27 out. Comments all end with a tokentizer.NL, so we need to make sure we don't
  28 errantly pick up non-comment tokens when parsing comment blocks.
  29
  30   ParseCode(): parse the code producing a list of logical lines.
  31 """
  32
  33 # TODO: Call from yapf_api.FormatCode.
  34
  35 import ast
  36 import codecs
  37 import os
  38 import token
  39 import tokenize
  40 from io import StringIO
  41 from tokenize import TokenInfo
  42
  43 from yapf.pyparser import split_penalty_visitor
  44 from yapf.yapflib import format_token
  45 from yapf.yapflib import logical_line
  46
  47 CONTINUATION = token.N_TOKENS
  48
  49
  50 def ParseCode(unformatted_source, filename='<unknown>'):
  51   """Parse a string of Python code into logical lines.
  52
  53   This provides an alternative entry point to YAPF.
  54
  55   Arguments:
  56     unformatted_source: (unicode) The code to format.
  57     filename: (unicode) The name of the file being reformatted.
  58
  59   Returns:
  60     A list of LogicalLines.
  61
  62   Raises:
  63     An exception is raised if there's an error during AST parsing.
  64   """
  65   if not unformatted_source.endswith(os.linesep):
  66     unformatted_source += os.linesep
  67
  68   try:
  69     ast_tree = ast.parse(unformatted_source, filename)
  70     ast.fix_missing_locations(ast_tree)
  71     readline = StringIO(unformatted_source).readline
  72     tokens = tokenize.generate_tokens(readline)
  73   except Exception:
  74     raise
  75
  76   logical_lines = _CreateLogicalLines(tokens)
  77
  78   # Process the logical lines.
  79   split_penalty_visitor.SplitPenalty(logical_lines).visit(ast_tree)
  80
  81   return logical_lines
  82
  83
  84 def _CreateLogicalLines(tokens):
  85   """Separate tokens into logical lines.
  86
  87   Arguments:
  88     tokens: (list of tokenizer.TokenInfo) Tokens generated by tokenizer.
  89
  90   Returns:
  91     A list of LogicalLines.
  92   """
  93   formatted_tokens = []
  94
  95   # Convert tokens into "TokenInfo" and add tokens for continuation markers.
  96   prev_tok = None
  97   for tok in tokens:
  98     tok = TokenInfo(*tok)
  99
 100     if (prev_tok and prev_tok.line.rstrip().endswith('\\') and
 101         prev_tok.start[0] < tok.start[0]):
 102       ctok = TokenInfo(
 103           type=CONTINUATION,
 104           string='\\',
 105           start=(prev_tok.start[0], prev_tok.start[1] + 1),
 106           end=(prev_tok.end[0], prev_tok.end[0] + 2),
 107           line=prev_tok.line)
 108       ctok.lineno = ctok.start[0]
 109       ctok.column = ctok.start[1]
 110       ctok.value = '\\'
 111       formatted_tokens.append(format_token.FormatToken(ctok, 'CONTINUATION'))
 112
 113     tok.lineno = tok.start[0]
 114     tok.column = tok.start[1]
 115     tok.value = tok.string
 116     formatted_tokens.append(
 117         format_token.FormatToken(tok, token.tok_name[tok.type]))
 118     prev_tok = tok
 119
 120   # Generate logical lines.
 121   logical_lines, cur_logical_line = [], []
 122   depth = 0
 123   for tok in formatted_tokens:
 124     if tok.type == tokenize.ENDMARKER:
 125       break
 126
 127     if tok.type == tokenize.NEWLINE:
 128       # End of a logical line.
 129       logical_lines.append(logical_line.LogicalLine(depth, cur_logical_line))
 130       cur_logical_line = []
 131     elif tok.type == tokenize.INDENT:
 132       depth += 1
 133     elif tok.type == tokenize.DEDENT:
 134       depth -= 1
 135     elif tok.type == tokenize.NL:
 136       pass
 137     else:
 138       if (cur_logical_line and not tok.type == tokenize.COMMENT and
 139           cur_logical_line[0].type == tokenize.COMMENT):
 140         # We were parsing a comment block, but now we have real code to worry
 141         # about. Store the comment and carry on.
 142         logical_lines.append(logical_line.LogicalLine(depth, cur_logical_line))
 143         cur_logical_line = []
 144
 145       cur_logical_line.append(tok)
 146
 147   # Link the FormatTokens in each line together to form a doubly linked list.
 148   for line in logical_lines:
 149     previous = line.first
 150     bracket_stack = [previous] if previous.OpensScope() else []
 151     for tok in line.tokens[1:]:
 152       tok.previous_token = previous
 153       previous.next_token = tok
 154       previous = tok
 155
 156       # Set up the "matching_bracket" attribute.
 157       if tok.OpensScope():
 158         bracket_stack.append(tok)
 159       elif tok.ClosesScope():
 160         bracket_stack[-1].matching_bracket = tok
 161         tok.matching_bracket = bracket_stack.pop()
 162
 163   return logical_lines