mirror of
https://github.com/davidhalter/parso.git
synced 2025-12-08 21:54:54 +08:00
271 lines
11 KiB
Python
271 lines
11 KiB
Python
from parso.python import tree
|
|
from parso.python.token import (DEDENT, INDENT, ENDMARKER, NEWLINE, NUMBER,
|
|
STRING, tok_name, NAME, FSTRING_STRING,
|
|
FSTRING_START, FSTRING_END)
|
|
from parso.parser import BaseParser
|
|
from parso.pgen2.parse import token_to_ilabel
|
|
|
|
|
|
class Parser(BaseParser):
|
|
"""
|
|
This class is used to parse a Python file, it then divides them into a
|
|
class structure of different scopes.
|
|
|
|
:param pgen_grammar: The grammar object of pgen2. Loaded by load_grammar.
|
|
"""
|
|
|
|
node_map = {
|
|
'expr_stmt': tree.ExprStmt,
|
|
'classdef': tree.Class,
|
|
'funcdef': tree.Function,
|
|
'file_input': tree.Module,
|
|
'import_name': tree.ImportName,
|
|
'import_from': tree.ImportFrom,
|
|
'break_stmt': tree.KeywordStatement,
|
|
'continue_stmt': tree.KeywordStatement,
|
|
'return_stmt': tree.ReturnStmt,
|
|
'raise_stmt': tree.KeywordStatement,
|
|
'yield_expr': tree.YieldExpr,
|
|
'del_stmt': tree.KeywordStatement,
|
|
'pass_stmt': tree.KeywordStatement,
|
|
'global_stmt': tree.GlobalStmt,
|
|
'nonlocal_stmt': tree.KeywordStatement,
|
|
'print_stmt': tree.KeywordStatement,
|
|
'assert_stmt': tree.AssertStmt,
|
|
'if_stmt': tree.IfStmt,
|
|
'with_stmt': tree.WithStmt,
|
|
'for_stmt': tree.ForStmt,
|
|
'while_stmt': tree.WhileStmt,
|
|
'try_stmt': tree.TryStmt,
|
|
'comp_for': tree.CompFor,
|
|
# Not sure if this is the best idea, but IMO it's the easiest way to
|
|
# avoid extreme amounts of work around the subtle difference of 2/3
|
|
# grammar in list comoprehensions.
|
|
'list_for': tree.CompFor,
|
|
# Same here. This just exists in Python 2.6.
|
|
'gen_for': tree.CompFor,
|
|
'decorator': tree.Decorator,
|
|
'lambdef': tree.Lambda,
|
|
'old_lambdef': tree.Lambda,
|
|
'lambdef_nocond': tree.Lambda,
|
|
}
|
|
default_node = tree.PythonNode
|
|
|
|
# Names/Keywords are handled separately
|
|
_leaf_map = {
|
|
STRING: tree.String,
|
|
NUMBER: tree.Number,
|
|
NEWLINE: tree.Newline,
|
|
ENDMARKER: tree.EndMarker,
|
|
FSTRING_STRING: tree.FStringString,
|
|
FSTRING_START: tree.FStringStart,
|
|
FSTRING_END: tree.FStringEnd,
|
|
}
|
|
|
|
def __init__(self, pgen_grammar, error_recovery=True, start_symbol='file_input'):
|
|
super(Parser, self).__init__(pgen_grammar, start_symbol, error_recovery=error_recovery)
|
|
|
|
self.syntax_errors = []
|
|
self._omit_dedent_list = []
|
|
self._indent_counter = 0
|
|
|
|
# TODO do print absolute import detection here.
|
|
# try:
|
|
# del python_grammar_no_print_statement.keywords["print"]
|
|
# except KeyError:
|
|
# pass # Doesn't exist in the Python 3 grammar.
|
|
|
|
# if self.options["print_function"]:
|
|
# python_grammar = pygram.python_grammar_no_print_statement
|
|
# else:
|
|
|
|
def parse(self, tokens):
|
|
if self._error_recovery:
|
|
if self._start_symbol != 'file_input':
|
|
raise NotImplementedError
|
|
|
|
tokens = self._recovery_tokenize(tokens)
|
|
|
|
node = super(Parser, self).parse(tokens)
|
|
|
|
if self._start_symbol == 'file_input' != node.type:
|
|
# If there's only one statement, we get back a non-module. That's
|
|
# not what we want, we want a module, so we add it here:
|
|
node = self.convert_node(
|
|
self._pgen_grammar,
|
|
self._pgen_grammar.symbol2number['file_input'],
|
|
[node]
|
|
)
|
|
|
|
return node
|
|
|
|
def convert_node(self, pgen_grammar, type, children):
|
|
"""
|
|
Convert raw node information to a PythonBaseNode instance.
|
|
|
|
This is passed to the parser driver which calls it whenever a reduction of a
|
|
grammar rule produces a new complete node, so that the tree is build
|
|
strictly bottom-up.
|
|
"""
|
|
# TODO REMOVE symbol, we don't want type here.
|
|
symbol = pgen_grammar.number2symbol[type]
|
|
try:
|
|
return self.node_map[symbol](children)
|
|
except KeyError:
|
|
if symbol == 'suite':
|
|
# We don't want the INDENT/DEDENT in our parser tree. Those
|
|
# leaves are just cancer. They are virtual leaves and not real
|
|
# ones and therefore have pseudo start/end positions and no
|
|
# prefixes. Just ignore them.
|
|
children = [children[0]] + children[2:-1]
|
|
elif symbol == 'list_if':
|
|
# Make transitioning from 2 to 3 easier.
|
|
symbol = 'comp_if'
|
|
elif symbol == 'listmaker':
|
|
# Same as list_if above.
|
|
symbol = 'testlist_comp'
|
|
return self.default_node(symbol, children)
|
|
|
|
def convert_leaf(self, pgen_grammar, type, value, prefix, start_pos):
|
|
# print('leaf', repr(value), token.tok_name[type])
|
|
if type == NAME:
|
|
if value in pgen_grammar.keywords:
|
|
return tree.Keyword(value, start_pos, prefix)
|
|
else:
|
|
return tree.Name(value, start_pos, prefix)
|
|
|
|
return self._leaf_map.get(type, tree.Operator)(value, start_pos, prefix)
|
|
|
|
def error_recovery(self, pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
|
|
add_token_callback):
|
|
def get_symbol_and_nodes(stack):
|
|
for dfa, state, (type_, nodes) in stack:
|
|
symbol = pgen_grammar.number2symbol[type_]
|
|
yield symbol, nodes
|
|
|
|
tos_nodes = stack.get_tos_nodes()
|
|
if tos_nodes:
|
|
last_leaf = tos_nodes[-1].get_last_leaf()
|
|
else:
|
|
last_leaf = None
|
|
|
|
if self._start_symbol == 'file_input' and \
|
|
(typ == ENDMARKER or typ == DEDENT and '\n' not in last_leaf.value):
|
|
def reduce_stack(states, newstate):
|
|
# reduce
|
|
state = newstate
|
|
while states[state] == [(0, state)]:
|
|
self.pgen_parser._pop()
|
|
|
|
dfa, state, (type_, nodes) = stack[-1]
|
|
states, first = dfa
|
|
|
|
# In Python statements need to end with a newline. But since it's
|
|
# possible (and valid in Python ) that there's no newline at the
|
|
# end of a file, we have to recover even if the user doesn't want
|
|
# error recovery.
|
|
#print('x', pprint.pprint(stack))
|
|
ilabel = token_to_ilabel(pgen_grammar, NEWLINE, value)
|
|
|
|
dfa, state, (type_, nodes) = stack[-1]
|
|
symbol = pgen_grammar.number2symbol[type_]
|
|
states, first = dfa
|
|
arcs = states[state]
|
|
# Look for a state with this label
|
|
for i, newstate in arcs:
|
|
if ilabel == i:
|
|
if symbol == 'simple_stmt':
|
|
# This is basically shifting
|
|
stack[-1] = (dfa, newstate, (type_, nodes))
|
|
|
|
reduce_stack(states, newstate)
|
|
add_token_callback(typ, value, start_pos, prefix)
|
|
return
|
|
# Check if we're at the right point
|
|
#for symbol, nodes in get_symbol_and_nodes(stack):
|
|
# self.pgen_parser._pop()
|
|
|
|
#break
|
|
break
|
|
#symbol = pgen_grammar.number2symbol[type_]
|
|
|
|
if not self._error_recovery:
|
|
return super(Parser, self).error_recovery(
|
|
pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
|
|
add_token_callback)
|
|
|
|
def current_suite(stack):
|
|
# For now just discard everything that is not a suite or
|
|
# file_input, if we detect an error.
|
|
one_line_suite = False
|
|
for index, (symbol, nodes) in reversed(list(enumerate(get_symbol_and_nodes(stack)))):
|
|
# `suite` can sometimes be only simple_stmt, not stmt.
|
|
if one_line_suite:
|
|
break
|
|
elif symbol == 'file_input':
|
|
break
|
|
elif symbol == 'suite':
|
|
if len(nodes) > 1:
|
|
break
|
|
elif not nodes:
|
|
one_line_suite = True
|
|
# `suite` without an indent are error nodes.
|
|
return index, symbol, nodes
|
|
|
|
index, symbol, nodes = current_suite(stack)
|
|
|
|
# print('err', token.tok_name[typ], repr(value), start_pos, len(stack), index)
|
|
if self._stack_removal(pgen_grammar, stack, arcs, index + 1, value, start_pos):
|
|
add_token_callback(typ, value, start_pos, prefix)
|
|
else:
|
|
if typ == INDENT:
|
|
# For every deleted INDENT we have to delete a DEDENT as well.
|
|
# Otherwise the parser will get into trouble and DEDENT too early.
|
|
self._omit_dedent_list.append(self._indent_counter)
|
|
|
|
error_leaf = tree.PythonErrorLeaf(tok_name[typ].lower(), value, start_pos, prefix)
|
|
stack[-1][2][1].append(error_leaf)
|
|
|
|
if symbol == 'suite':
|
|
dfa, state, node = stack[-1]
|
|
states, first = dfa
|
|
arcs = states[state]
|
|
intended_label = pgen_grammar.symbol2label['stmt']
|
|
# Introduce a proper state transition. We're basically allowing
|
|
# there to be no valid statements inside a suite.
|
|
if [x[0] for x in arcs] == [intended_label]:
|
|
new_state = arcs[0][1]
|
|
stack[-1] = dfa, new_state, node
|
|
|
|
def _stack_removal(self, pgen_grammar, stack, arcs, start_index, value, start_pos):
|
|
failed_stack = False
|
|
found = False
|
|
all_nodes = []
|
|
for dfa, state, (type_, nodes) in stack[start_index:]:
|
|
if nodes:
|
|
found = True
|
|
if found:
|
|
failed_stack = True
|
|
all_nodes += nodes
|
|
if failed_stack:
|
|
stack[start_index - 1][2][1].append(tree.PythonErrorNode(all_nodes))
|
|
|
|
stack[start_index:] = []
|
|
return failed_stack
|
|
|
|
def _recovery_tokenize(self, tokens):
|
|
for typ, value, start_pos, prefix in tokens:
|
|
# print(tok_name[typ], repr(value), start_pos, repr(prefix))
|
|
if typ == DEDENT:
|
|
# We need to count indents, because if we just omit any DEDENT,
|
|
# we might omit them in the wrong place.
|
|
o = self._omit_dedent_list
|
|
if o and o[-1] == self._indent_counter:
|
|
o.pop()
|
|
continue
|
|
|
|
self._indent_counter -= 1
|
|
elif typ == INDENT:
|
|
self._indent_counter += 1
|
|
yield typ, value, start_pos, prefix
|