Python3.src.antlr4.RuleContext.py Maven / Gradle / Ivy
Show all versions of antlr4-runtime-testsuite Show documentation
# [The "BSD license"]
# Copyright (c) 2013 Terence Parr
# Copyright (c) 2013 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.
#/
# A rule context is a record of a single rule invocation. It knows
# which context invoked it, if any. If there is no parent context, then
# naturally the invoking state is not valid. The parent link
# provides a chain upwards from the current rule invocation to the root
# of the invocation tree, forming a stack. We actually carry no
# information about the rule associated with this context (except
# when parsing). We keep only the state number of the invoking state from
# the ATN submachine that invoked this. Contrast this with the s
# pointer inside ParserRuleContext that tracks the current state
# being "executed" for the current rule.
#
# The parent contexts are useful for computing lookahead sets and
# getting error information.
#
# These objects are used during parsing and prediction.
# For the special case of parsers, we use the subclass
# ParserRuleContext.
#
# @see ParserRuleContext
#/
from io import StringIO
from antlr4.tree.Tree import RuleNode, INVALID_INTERVAL, ParseTreeVisitor
from antlr4.tree.Trees import Trees
# need forward declarations
RuleContext = None
Parser = None
class RuleContext(RuleNode):
EMPTY = None
def __init__(self, parent:RuleContext=None, invokingState:int=-1):
super().__init__()
# What context invoked this rule?
self.parentCtx = parent
# What state invoked the rule associated with this context?
# The "return address" is the followState of invokingState
# If parent is null, this should be -1.
self.invokingState = invokingState
def depth(self):
n = 0
p = self
while p is not None:
p = p.parentCtx
n += 1
return n
# A context is empty if there is no invoking state; meaning nobody call
# current context.
def isEmpty(self):
return self.invokingState == -1
# satisfy the ParseTree / SyntaxTree interface
def getSourceInterval(self):
return INVALID_INTERVAL
def getRuleContext(self):
return self
def getPayload(self):
return self
# Return the combined text of all child nodes. This method only considers
# tokens which have been added to the parse tree.
#
# Since tokens on hidden channels (e.g. whitespace or comments) are not
# added to the parse trees, they will not appear in the output of this
# method.
#/
def getText(self):
if self.getChildCount() == 0:
return ""
with StringIO() as builder:
for child in self.getChildren():
builder.write(child.getText())
return builder.getvalue()
def getRuleIndex(self):
return -1
# For rule associated with this parse tree internal node, return
# the outer alternative number used to match the input. Default
# implementation does not compute nor store this alt num. Create
# a subclass of ParserRuleContext with backing field and set
# option contextSuperClass.
# to set it.
def getAltNumber(self):
return 0 # should use ATN.INVALID_ALT_NUMBER but won't compile
# Set the outer alternative number for this context node. Default
# implementation does nothing to avoid backing field overhead for
# trees that don't need it. Create
# a subclass of ParserRuleContext with backing field and set
# option contextSuperClass.
def setAltNumber(self, altNumber:int):
pass
def getChild(self, i:int):
return None
def getChildCount(self):
return 0
def getChildren(self):
for c in []:
yield c
def accept(self, visitor:ParseTreeVisitor):
return visitor.visitChildren(self)
# # Call this method to view a parse tree in a dialog box visually.#/
# public Future inspect(@Nullable Parser parser) {
# List ruleNames = parser != null ? Arrays.asList(parser.getRuleNames()) : null;
# return inspect(ruleNames);
# }
#
# public Future inspect(@Nullable List ruleNames) {
# TreeViewer viewer = new TreeViewer(ruleNames, this);
# return viewer.open();
# }
#
# # Save this tree in a postscript file#/
# public void save(@Nullable Parser parser, String fileName)
# throws IOException, PrintException
# {
# List ruleNames = parser != null ? Arrays.asList(parser.getRuleNames()) : null;
# save(ruleNames, fileName);
# }
#
# # Save this tree in a postscript file using a particular font name and size#/
# public void save(@Nullable Parser parser, String fileName,
# String fontName, int fontSize)
# throws IOException
# {
# List ruleNames = parser != null ? Arrays.asList(parser.getRuleNames()) : null;
# save(ruleNames, fileName, fontName, fontSize);
# }
#
# # Save this tree in a postscript file#/
# public void save(@Nullable List ruleNames, String fileName)
# throws IOException, PrintException
# {
# Trees.writePS(this, ruleNames, fileName);
# }
#
# # Save this tree in a postscript file using a particular font name and size#/
# public void save(@Nullable List ruleNames, String fileName,
# String fontName, int fontSize)
# throws IOException
# {
# Trees.writePS(this, ruleNames, fileName, fontName, fontSize);
# }
#
# # Print out a whole tree, not just a node, in LISP format
# # (root child1 .. childN). Print just a node if this is a leaf.
# # We have to know the recognizer so we can get rule names.
# #/
# @Override
# public String toStringTree(@Nullable Parser recog) {
# return Trees.toStringTree(this, recog);
# }
#
# Print out a whole tree, not just a node, in LISP format
# (root child1 .. childN). Print just a node if this is a leaf.
#
def toStringTree(self, ruleNames:list=None, recog:Parser=None):
return Trees.toStringTree(self, ruleNames=ruleNames, recog=recog)
# }
#
# @Override
# public String toStringTree() {
# return toStringTree((List)null);
# }
#
def __str__(self):
return self.toString(None, None)
# @Override
# public String toString() {
# return toString((List)null, (RuleContext)null);
# }
#
# public final String toString(@Nullable Recognizer recog) {
# return toString(recog, ParserRuleContext.EMPTY);
# }
#
# public final String toString(@Nullable List ruleNames) {
# return toString(ruleNames, null);
# }
#
# // recog null unless ParserRuleContext, in which case we use subclass toString(...)
# public String toString(@Nullable Recognizer recog, @Nullable RuleContext stop) {
# String[] ruleNames = recog != null ? recog.getRuleNames() : null;
# List ruleNamesList = ruleNames != null ? Arrays.asList(ruleNames) : null;
# return toString(ruleNamesList, stop);
# }
def toString(self, ruleNames:list, stop:RuleContext)->str:
with StringIO() as buf:
p = self
buf.write("[")
while p is not None and p is not stop:
if ruleNames is None:
if not p.isEmpty():
buf.write(str(p.invokingState))
else:
ri = p.getRuleIndex()
ruleName = ruleNames[ri] if ri >= 0 and ri < len(ruleNames) else str(ri)
buf.write(ruleName)
if p.parentCtx is not None and (ruleNames is not None or not p.parentCtx.isEmpty()):
buf.write(" ")
p = p.parentCtx
buf.write("]")
return buf.getvalue()