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# | |
# Copyright (c) 2012-2017 The ANTLR Project. All rights reserved. | |
# Use of this file is governed by the BSD 3-clause license that | |
# can be found in the LICENSE.txt file in the project root. | |
# | |
from io import StringIO | |
from antlr4.Token import Token | |
from antlr4.CommonTokenStream import CommonTokenStream | |
class TokenStreamRewriter(object): | |
__slots__ = ('tokens', 'programs', 'lastRewriteTokenIndexes') | |
DEFAULT_PROGRAM_NAME = "default" | |
PROGRAM_INIT_SIZE = 100 | |
MIN_TOKEN_INDEX = 0 | |
def __init__(self, tokens): | |
""" | |
:type tokens: antlr4.BufferedTokenStream.BufferedTokenStream | |
:param tokens: | |
:return: | |
""" | |
super(TokenStreamRewriter, self).__init__() | |
self.tokens = tokens | |
self.programs = {self.DEFAULT_PROGRAM_NAME: []} | |
self.lastRewriteTokenIndexes = {} | |
def getTokenStream(self): | |
return self.tokens | |
def rollback(self, instruction_index, program_name): | |
ins = self.programs.get(program_name, None) | |
if ins: | |
self.programs[program_name] = ins[self.MIN_TOKEN_INDEX: instruction_index] | |
def deleteProgram(self, program_name=DEFAULT_PROGRAM_NAME): | |
self.rollback(self.MIN_TOKEN_INDEX, program_name) | |
def insertAfterToken(self, token, text, program_name=DEFAULT_PROGRAM_NAME): | |
self.insertAfter(token.tokenIndex, text, program_name) | |
def insertAfter(self, index, text, program_name=DEFAULT_PROGRAM_NAME): | |
op = self.InsertAfterOp(self.tokens, index + 1, text) | |
rewrites = self.getProgram(program_name) | |
op.instructionIndex = len(rewrites) | |
rewrites.append(op) | |
def insertBeforeIndex(self, index, text): | |
self.insertBefore(self.DEFAULT_PROGRAM_NAME, index, text) | |
def insertBeforeToken(self, token, text, program_name=DEFAULT_PROGRAM_NAME): | |
self.insertBefore(program_name, token.tokenIndex, text) | |
def insertBefore(self, program_name, index, text): | |
op = self.InsertBeforeOp(self.tokens, index, text) | |
rewrites = self.getProgram(program_name) | |
op.instructionIndex = len(rewrites) | |
rewrites.append(op) | |
def replaceIndex(self, index, text): | |
self.replace(self.DEFAULT_PROGRAM_NAME, index, index, text) | |
def replaceRange(self, from_idx, to_idx, text): | |
self.replace(self.DEFAULT_PROGRAM_NAME, from_idx, to_idx, text) | |
def replaceSingleToken(self, token, text): | |
self.replace(self.DEFAULT_PROGRAM_NAME, token.tokenIndex, token.tokenIndex, text) | |
def replaceRangeTokens(self, from_token, to_token, text, program_name=DEFAULT_PROGRAM_NAME): | |
self.replace(program_name, from_token.tokenIndex, to_token.tokenIndex, text) | |
def replace(self, program_name, from_idx, to_idx, text): | |
if any((from_idx > to_idx, from_idx < 0, to_idx < 0, to_idx >= len(self.tokens.tokens))): | |
raise ValueError( | |
'replace: range invalid: {}..{}(size={})'.format(from_idx, to_idx, len(self.tokens.tokens))) | |
op = self.ReplaceOp(from_idx, to_idx, self.tokens, text) | |
rewrites = self.getProgram(program_name) | |
op.instructionIndex = len(rewrites) | |
rewrites.append(op) | |
def deleteToken(self, token): | |
self.delete(self.DEFAULT_PROGRAM_NAME, token, token) | |
def deleteIndex(self, index): | |
self.delete(self.DEFAULT_PROGRAM_NAME, index, index) | |
def delete(self, program_name, from_idx, to_idx): | |
if isinstance(from_idx, Token): | |
self.replace(program_name, from_idx.tokenIndex, to_idx.tokenIndex, "") | |
else: | |
self.replace(program_name, from_idx, to_idx, "") | |
def lastRewriteTokenIndex(self, program_name=DEFAULT_PROGRAM_NAME): | |
return self.lastRewriteTokenIndexes.get(program_name, -1) | |
def setLastRewriteTokenIndex(self, program_name, i): | |
self.lastRewriteTokenIndexes[program_name] = i | |
def getProgram(self, program_name): | |
return self.programs.setdefault(program_name, []) | |
def getDefaultText(self): | |
return self.getText(self.DEFAULT_PROGRAM_NAME, 0, len(self.tokens.tokens) - 1) | |
def getText(self, program_name, start:int, stop:int): | |
""" | |
:return: the text in tokens[start, stop](closed interval) | |
""" | |
rewrites = self.programs.get(program_name) | |
# ensure start/end are in range | |
if stop > len(self.tokens.tokens) - 1: | |
stop = len(self.tokens.tokens) - 1 | |
if start < 0: | |
start = 0 | |
# if no instructions to execute | |
if not rewrites: return self.tokens.getText(start, stop) | |
buf = StringIO() | |
indexToOp = self._reduceToSingleOperationPerIndex(rewrites) | |
i = start | |
while all((i <= stop, i < len(self.tokens.tokens))): | |
op = indexToOp.pop(i, None) | |
token = self.tokens.get(i) | |
if op is None: | |
if token.type != Token.EOF: buf.write(token.text) | |
i += 1 | |
else: | |
i = op.execute(buf) | |
if stop == len(self.tokens.tokens)-1: | |
for op in indexToOp.values(): | |
if op.index >= len(self.tokens.tokens)-1: buf.write(op.text) | |
return buf.getvalue() | |
def _reduceToSingleOperationPerIndex(self, rewrites): | |
# Walk replaces | |
for i, rop in enumerate(rewrites): | |
if any((rop is None, not isinstance(rop, TokenStreamRewriter.ReplaceOp))): | |
continue | |
# Wipe prior inserts within range | |
inserts = [op for op in rewrites[:i] if isinstance(op, TokenStreamRewriter.InsertBeforeOp)] | |
for iop in inserts: | |
if iop.index == rop.index: | |
rewrites[iop.instructionIndex] = None | |
rop.text = '{}{}'.format(iop.text, rop.text) | |
elif all((iop.index > rop.index, iop.index <= rop.last_index)): | |
rewrites[iop.instructionIndex] = None | |
# Drop any prior replaces contained within | |
prevReplaces = [op for op in rewrites[:i] if isinstance(op, TokenStreamRewriter.ReplaceOp)] | |
for prevRop in prevReplaces: | |
if all((prevRop.index >= rop.index, prevRop.last_index <= rop.last_index)): | |
rewrites[prevRop.instructionIndex] = None | |
continue | |
isDisjoint = any((prevRop.last_index<rop.index, prevRop.index>rop.last_index)) | |
if all((prevRop.text is None, rop.text is None, not isDisjoint)): | |
rewrites[prevRop.instructionIndex] = None | |
rop.index = min(prevRop.index, rop.index) | |
rop.last_index = min(prevRop.last_index, rop.last_index) | |
print('New rop {}'.format(rop)) | |
elif (not(isDisjoint)): | |
raise ValueError("replace op boundaries of {} overlap with previous {}".format(rop, prevRop)) | |
# Walk inserts | |
for i, iop in enumerate(rewrites): | |
if any((iop is None, not isinstance(iop, TokenStreamRewriter.InsertBeforeOp))): | |
continue | |
prevInserts = [op for op in rewrites[:i] if isinstance(op, TokenStreamRewriter.InsertBeforeOp)] | |
for prev_index, prevIop in enumerate(prevInserts): | |
if prevIop.index == iop.index and type(prevIop) is TokenStreamRewriter.InsertBeforeOp: | |
iop.text += prevIop.text | |
rewrites[prev_index] = None | |
elif prevIop.index == iop.index and type(prevIop) is TokenStreamRewriter.InsertAfterOp: | |
iop.text = prevIop.text + iop.text | |
rewrites[prev_index] = None | |
# look for replaces where iop.index is in range; error | |
prevReplaces = [op for op in rewrites[:i] if isinstance(op, TokenStreamRewriter.ReplaceOp)] | |
for rop in prevReplaces: | |
if iop.index == rop.index: | |
rop.text = iop.text + rop.text | |
rewrites[i] = None | |
continue | |
if all((iop.index >= rop.index, iop.index <= rop.last_index)): | |
raise ValueError("insert op {} within boundaries of previous {}".format(iop, rop)) | |
reduced = {} | |
for i, op in enumerate(rewrites): | |
if op is None: continue | |
if reduced.get(op.index): raise ValueError('should be only one op per index') | |
reduced[op.index] = op | |
return reduced | |
class RewriteOperation(object): | |
__slots__ = ('tokens', 'index', 'text', 'instructionIndex') | |
def __init__(self, tokens, index, text=""): | |
""" | |
:type tokens: CommonTokenStream | |
:param tokens: | |
:param index: | |
:param text: | |
:return: | |
""" | |
self.tokens = tokens | |
self.index = index | |
self.text = text | |
self.instructionIndex = 0 | |
def execute(self, buf): | |
""" | |
:type buf: StringIO.StringIO | |
:param buf: | |
:return: | |
""" | |
return self.index | |
def __str__(self): | |
return '<{}@{}:"{}">'.format(self.__class__.__name__, self.tokens.get(self.index), self.text) | |
class InsertBeforeOp(RewriteOperation): | |
def __init__(self, tokens, index, text=""): | |
super(TokenStreamRewriter.InsertBeforeOp, self).__init__(tokens, index, text) | |
def execute(self, buf): | |
buf.write(self.text) | |
if self.tokens.get(self.index).type != Token.EOF: | |
buf.write(self.tokens.get(self.index).text) | |
return self.index + 1 | |
class InsertAfterOp(InsertBeforeOp): | |
pass | |
class ReplaceOp(RewriteOperation): | |
__slots__ = 'last_index' | |
def __init__(self, from_idx, to_idx, tokens, text): | |
super(TokenStreamRewriter.ReplaceOp, self).__init__(tokens, from_idx, text) | |
self.last_index = to_idx | |
def execute(self, buf): | |
if self.text: | |
buf.write(self.text) | |
return self.last_index + 1 | |
def __str__(self): | |
if self.text: | |
return '<ReplaceOp@{}..{}:"{}">'.format(self.tokens.get(self.index), self.tokens.get(self.last_index), | |
self.text) | |