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The ANTLR 4 grammar compiler.
/*
* Copyright (c) 2012 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.
*/
package org.antlr.v4.codegen.model;
import org.antlr.v4.codegen.CodeGenerator;
import org.antlr.v4.codegen.OutputModelFactory;
import org.antlr.v4.codegen.model.decl.RuleContextDecl;
import org.antlr.v4.codegen.model.decl.RuleContextListDecl;
import org.antlr.v4.codegen.model.decl.StructDecl;
import org.antlr.v4.parse.ANTLRParser;
import org.antlr.v4.runtime.misc.Tuple2;
import org.antlr.v4.tool.LeftRecursiveRule;
import org.antlr.v4.tool.Rule;
import org.antlr.v4.tool.ast.GrammarAST;
public class LeftRecursiveRuleFunction extends RuleFunction {
public LeftRecursiveRuleFunction(OutputModelFactory factory, LeftRecursiveRule r) {
super(factory, r);
// Since we delete x=lr, we have to manually add decls for all labels
// on left-recur refs to proper structs
for (Tuple2 pair : r.leftRecursiveRuleRefLabels) {
GrammarAST idAST = pair.getItem1();
String altLabel = pair.getItem2();
String label = idAST.getText();
GrammarAST rrefAST = (GrammarAST)idAST.getParent().getChild(1);
if ( rrefAST.getType() == ANTLRParser.RULE_REF ) {
Rule targetRule = factory.getGrammar().getRule(rrefAST.getText());
String ctxName = factory.getTarget().getRuleFunctionContextStructName(targetRule);
RuleContextDecl d;
if (idAST.getParent().getType() == ANTLRParser.ASSIGN) {
d = new RuleContextDecl(factory, label, ctxName);
}
else {
d = new RuleContextListDecl(factory, label, ctxName);
}
StructDecl struct = ruleCtx;
if ( altLabelCtxs!=null ) {
StructDecl s = altLabelCtxs.get(altLabel);
if ( s!=null ) struct = s; // if alt label, use subctx
}
struct.addDecl(d); // stick in overall rule's ctx
}
}
}
}