vscode-python/pythonFiles/parso/python/parser.py at master · litleleprikon/vscode-python · GitHub

History

265 lines (228 loc) · 10.4 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

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.

for index, (symbol, nodes) in reversed(list(enumerate(get_symbol_and_nodes(stack)))):

# `suite` can sometimes be only simple_stmt, not stmt.

if symbol == 'file_input':

break

elif symbol == 'suite' and len(nodes) > 1:

# suites without an indent in them get discarded.

break

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

vscode-python/pythonFiles/parso/python/parser.py at master · litleleprikon/vscode-python · GitHub

Expand file tree

Breadcrumbs

parser.py

Latest commit

History

Breadcrumbs

parser.py

File metadata and controls