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Diffstat (limited to 'sphinx/pycode/pgen2/parse.pyx')
| -rw-r--r-- | sphinx/pycode/pgen2/parse.pyx | 165 |
1 files changed, 0 insertions, 165 deletions
diff --git a/sphinx/pycode/pgen2/parse.pyx b/sphinx/pycode/pgen2/parse.pyx deleted file mode 100644 index 9c97a4539..000000000 --- a/sphinx/pycode/pgen2/parse.pyx +++ /dev/null @@ -1,165 +0,0 @@ -# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved. -# Licensed to PSF under a Contributor Agreement. - -# Adapted from parse.py to be compiled with Cython by Georg Brandl. - -"""Parser engine for the grammar tables generated by pgen. - -The grammar table must be loaded first. - -See Parser/parser.c in the Python distribution for additional info on -how this parsing engine works. - -""" - -from sphinx.pycode.nodes import Node, Leaf - -DEF NAME = 1 - -class ParseError(Exception): - """Exception to signal the parser is stuck.""" - - def __init__(self, msg, type, value, context): - Exception.__init__(self, "%s: type=%r, value=%r, context=%r" % - (msg, type, value, context)) - self.msg = msg - self.type = type - self.value = value - self.context = context - - -cdef class Parser: - cdef public object grammar - cdef public object rootnode - cdef public list stack - cdef public set used_names - cdef int _grammar_start - cdef list _grammar_labels - cdef dict _grammar_dfas - cdef dict _grammar_keywords - cdef dict _grammar_tokens - cdef dict _grammar_number2symbol - - def __init__(self, grammar, convert=None): - self.grammar = grammar - #self.convert = convert or noconvert - - self._grammar_dfas = grammar.dfas - self._grammar_labels = grammar.labels - self._grammar_keywords = grammar.keywords - self._grammar_tokens = grammar.tokens - self._grammar_number2symbol = grammar.number2symbol - self._grammar_start = grammar.start - - def setup(self, start=None): - if start is None: - start = self._grammar_start - # Each stack entry is a tuple: (dfa, state, node). - # A node is a tuple: (type, value, context, children), - # where children is a list of nodes or None, and context may be None. - newnode = (start, None, None, []) - stackentry = (self._grammar_dfas[start], 0, newnode) - self.stack = [stackentry] - self.rootnode = None - self.used_names = set() # Aliased to self.rootnode.used_names in pop() - - def addtoken(self, int type, value, context): - """Add a token; return True iff this is the end of the program.""" - cdef int ilabel, i, t, state, newstate - # Map from token to label - ilabel = self.classify(type, value, context) - # Loop until the token is shifted; may raise exceptions - while True: - dfa, state, node = self.stack[-1] - states, first = dfa - arcs = states[state] - # Look for a state with this label - for i, newstate in arcs: - t, v = self._grammar_labels[i] - if ilabel == i: - # Look it up in the list of labels - ## assert t < 256 - # Shift a token; we're done with it - self.shift(type, value, newstate, context) - # Pop while we are in an accept-only state - state = newstate - while states[state] == [(0, state)]: - self.pop() - if not self.stack: - # Done parsing! - return True - dfa, state, node = self.stack[-1] - states, first = dfa - # Done with this token - return False - elif t >= 256: - # See if it's a symbol and if we're in its first set - itsdfa = self._grammar_dfas[t] - itsstates, itsfirst = itsdfa - if ilabel in itsfirst: - # Push a symbol - self.push(t, itsdfa, newstate, context) - break # To continue the outer while loop - else: - if (0, state) in arcs: - # An accepting state, pop it and try something else - self.pop() - if not self.stack: - # Done parsing, but another token is input - raise ParseError("too much input", - type, value, context) - else: - # No success finding a transition - raise ParseError("bad input", type, value, context) - - cdef int classify(self, int type, value, context): - """Turn a token into a label. (Internal)""" - if type == NAME: - # Keep a listing of all used names - self.used_names.add(value) - # Check for reserved words - if value in self._grammar_keywords: - return self._grammar_keywords[value] - if type not in self._grammar_tokens: - raise ParseError("bad token", type, value, context) - return self._grammar_tokens[type] - - cdef void shift(self, type, value, newstate, context): - """Shift a token. (Internal)""" - cdef tuple node - dfa, state, node = self.stack[-1] - newnode = (type, value, context, None) - newnode = self.convert(newnode) - if newnode is not None: - node[-1].append(newnode) - self.stack[-1] = (dfa, newstate, node) - - cdef void push(self, type, newdfa, newstate, context): - """Push a nonterminal. (Internal)""" - dfa, state, node = self.stack[-1] - newnode = (type, None, context, []) - self.stack[-1] = (dfa, newstate, node) - self.stack.append((newdfa, 0, newnode)) - - cdef void pop(self): - """Pop a nonterminal. (Internal)""" - popdfa, popstate, popnode = self.stack.pop() - newnode = self.convert(popnode) - if newnode is not None: - if self.stack: - dfa, state, node = self.stack[-1] - node[-1].append(newnode) - else: - self.rootnode = newnode - self.rootnode.used_names = self.used_names - - cdef convert(self, tuple raw_node): - type, value, context, children = raw_node - if children or type in self._grammar_number2symbol: - # If there's exactly one child, return that child instead of - # creating a new node. - if len(children) == 1: - return children[0] - return Node(type, children, context=context) - else: - return Leaf(type, value, context=context) |