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A collection of tests for ANTLR 4 Runtime libraries.
#
# [The "BSD license"]
# Copyright (c) 2012 Terence Parr
# Copyright (c) 2012 Sam Harwell
# Copyright (c) 2014 Eric Vergnaud
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Specialized {@link Set}{@code <}{@link ATNConfig}{@code >} that can track
# info about the set, with support for combining similar configurations using a
# graph-structured stack.
#/
from io import StringIO
from antlr4.PredictionContext import merge
from antlr4.Utils import str_list
from antlr4.atn.ATN import ATN
from antlr4.atn.SemanticContext import SemanticContext
from antlr4.error.Errors import UnsupportedOperationException, IllegalStateException
class ATNConfigSet(object):
#
# The reason that we need this is because we don't want the hash map to use
# the standard hash code and equals. We need all configurations with the same
# {@code (s,i,_,semctx)} to be equal. Unfortunately, this key effectively doubles
# the number of objects associated with ATNConfigs. The other solution is to
# use a hash table that lets us specify the equals/hashcode operation.
def __init__(self, fullCtx=True):
# All configs but hashed by (s, i, _, pi) not including context. Wiped out
# when we go readonly as this set becomes a DFA state.
self.configLookup = dict()
# Indicates that this configuration set is part of a full context
# LL prediction. It will be used to determine how to merge $. With SLL
# it's a wildcard whereas it is not for LL context merge.
self.fullCtx = fullCtx
# Indicates that the set of configurations is read-only. Do not
# allow any code to manipulate the set; DFA states will point at
# the sets and they must not change. This does not protect the other
# fields; in particular, conflictingAlts is set after
# we've made this readonly.
self.readonly = False
# Track the elements as they are added to the set; supports get(i)#/
self.configs = []
# TODO: these fields make me pretty uncomfortable but nice to pack up info together, saves recomputation
# TODO: can we track conflicts as they are added to save scanning configs later?
self.uniqueAlt = 0
self.conflictingAlts = None
# Used in parser and lexer. In lexer, it indicates we hit a pred
# while computing a closure operation. Don't make a DFA state from this.
self.hasSemanticContext = False
self.dipsIntoOuterContext = False
self.cachedHashCode = -1
def __iter__(self):
return self.configs.__iter__()
# Adding a new config means merging contexts with existing configs for
# {@code (s, i, pi, _)}, where {@code s} is the
# {@link ATNConfig#state}, {@code i} is the {@link ATNConfig#alt}, and
# {@code pi} is the {@link ATNConfig#semanticContext}. We use
# {@code (s,i,pi)} as key.
#
# This method updates {@link #dipsIntoOuterContext} and
# {@link #hasSemanticContext} when necessary.
#/
def add(self, config, mergeCache=None):
if self.readonly:
raise Exception("This set is readonly")
if config.semanticContext is not SemanticContext.NONE:
self.hasSemanticContext = True
if config.reachesIntoOuterContext > 0:
self.dipsIntoOuterContext = True
existing = self.getOrAdd(config)
if existing is config:
self.cachedHashCode = -1
self.configs.append(config) # track order here
return True
# a previous (s,i,pi,_), merge with it and save result
rootIsWildcard = not self.fullCtx
merged = merge(existing.context, config.context, rootIsWildcard, mergeCache)
# no need to check for existing.context, config.context in cache
# since only way to create new graphs is "call rule" and here. We
# cache at both places.
existing.reachesIntoOuterContext = max(existing.reachesIntoOuterContext, config.reachesIntoOuterContext)
# make sure to preserve the precedence filter suppression during the merge
if config.precedenceFilterSuppressed:
existing.precedenceFilterSuppressed = True
existing.context = merged # replace context; no need to alt mapping
return True
def getOrAdd(self, config):
h = hash(config)
l = self.configLookup.get(h, None)
if l is not None:
for c in l:
if c==config:
return c
if l is None:
l = [config]
self.configLookup[h] = l
else:
l.append(config)
return config
def getStates(self):
states = set()
for c in self.configs:
states.add(c.state)
return states
def getPredicates(self):
preds = list()
for c in self.configs:
if c.semanticContext!=SemanticContext.NONE:
preds.append(c.semanticContext)
return preds
def get(self, i):
return self.configs[i]
def optimizeConfigs(self, interpreter):
if self.readonly:
raise IllegalStateException("This set is readonly")
if len(self.configs)==0:
return
for config in self.configs:
config.context = interpreter.getCachedContext(config.context)
def addAll(self, coll):
for c in coll:
self.add(c)
return False
def __eq__(self, other):
if self is other:
return True
elif not isinstance(other, ATNConfigSet):
return False
same = self.configs is not None and \
self.configs == other.configs and \
self.fullCtx == other.fullCtx and \
self.uniqueAlt == other.uniqueAlt and \
self.conflictingAlts == other.conflictingAlts and \
self.hasSemanticContext == other.hasSemanticContext and \
self.dipsIntoOuterContext == other.dipsIntoOuterContext
return same
def __hash__(self):
if self.readonly:
if self.cachedHashCode == -1:
self.cachedHashCode = self.hashConfigs()
return self.cachedHashCode
return self.hashConfigs()
def hashConfigs(self):
h = 0
for cfg in self.configs:
h = hash((h, cfg))
return h
def __len__(self):
return len(self.configs)
def isEmpty(self):
return len(self.configs)==0
def __contains__(self, config):
if self.configLookup is None:
raise UnsupportedOperationException("This method is not implemented for readonly sets.")
h = hash(config)
l = self.configLookup.get(h, None)
return l is not None and config in l
def clear(self):
if self.readonly:
raise IllegalStateException("This set is readonly")
self.configs.clear()
self.cachedHashCode = -1
self.configLookup.clear()
def setReadonly(self, readonly):
self.readonly = readonly
self.configLookup = None # can't mod, no need for lookup cache
def __str__(self):
return unicode(self)
def __unicode__(self):
with StringIO() as buf:
buf.write(str_list(self.configs))
if self.hasSemanticContext:
buf.write(u",hasSemanticContext=")
buf.write(unicode(self.hasSemanticContext))
if self.uniqueAlt!=ATN.INVALID_ALT_NUMBER:
buf.write(u",uniqueAlt=")
buf.write(unicode(self.uniqueAlt))
if self.conflictingAlts is not None:
buf.write(u",conflictingAlts=")
buf.write(unicode(self.conflictingAlts))
if self.dipsIntoOuterContext:
buf.write(u",dipsIntoOuterContext")
return buf.getvalue()
class OrderedATNConfigSet(ATNConfigSet):
def __init__(self):
super(OrderedATNConfigSet, self).__init__()
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