public Class LeftRecursiveRuleTransformer

Class Inheritance

extends Object

java.lang.Object
org.antlr.v4.analysis.LeftRecursiveRuleTransformer

Imports

org.antlr.runtime.ANTLRStringStream, .CommonTokenStream, .ParserRuleReturnScope, .RecognitionException, .Token, org.antlr.v4.Tool, org.antlr.v4.misc.OrderedHashMap, org.antlr.v4.parse.ANTLRLexer, .ANTLRParser, .GrammarASTAdaptor, .ScopeParser, .ToolANTLRParser, org.antlr.v4.runtime.misc.Pair, org.antlr.v4.semantics.BasicSemanticChecks, .RuleCollector, org.antlr.v4.tool.AttributeDict, .ErrorType, .Grammar, .GrammarTransformPipeline, .LabelElementPair, .LeftRecursiveRule, .Rule, org.antlr.v4.tool.ast.ActionAST, .AltAST, .BlockAST, .GrammarAST, .GrammarASTWithOptions, .GrammarRootAST, .RuleAST, java.util.ArrayList, .Collection, .List

Remove left-recursive rule refs, add precedence args to recursive rule refs. Rewrite rule so we can create ATN. MODIFIES grammar AST in place.

Field Summary

Modifier and Type	Field and Description
public GrammarRootAST	ast
public Grammar	g
public static final String	PRECEDENCE_OPTION_NAME
public Collection<Rule>	rules
public static final String	TOKENINDEX_OPTION_NAME
public Tool	tool

Constructor Summary

Access	Constructor and Description
public	LeftRecursiveRuleTransformer(GrammarRootAST ast, Collection<Rule> rules, Grammar g)

Method Summary

Modifier and Type	Method and Description
public RuleAST	parseArtificialRule(final Grammar g, String ruleText)
public void	setAltASTPointers(LeftRecursiveRule r, RuleAST t) (RULE e int _p (returns int v) (BLOCK (ALT (BLOCK (ALT INT {$v = $INT.int;}) (ALT '(' (= x e) ')' {$v = $x.v;}) (ALT ID)) (* (BLOCK (OPTIONS ...) (ALT {7 >= $_p}?
public boolean	translateLeftRecursiveRule(GrammarRootAST ast, LeftRecursiveRule r, String language) Return true if successful
public void	translateLeftRecursiveRules()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

ast	back to summary
public GrammarRootAST ast

g	back to summary
public Grammar g

PRECEDENCE_OPTION_NAME	back to summary
public static final String PRECEDENCE_OPTION_NAME

rules	back to summary
public Collection<Rule> rules

TOKENINDEX_OPTION_NAME	back to summary
public static final String TOKENINDEX_OPTION_NAME

tool	back to summary
public Tool tool

Constructor Detail

LeftRecursiveRuleTransformer	back to summary
public LeftRecursiveRuleTransformer(GrammarRootAST ast, Collection<Rule> rules, Grammar g)

Method Detail

parseArtificialRule	back to summary
public RuleAST parseArtificialRule(final Grammar g, String ruleText)

setAltASTPointers	back to summary
public void setAltASTPointers(LeftRecursiveRule r, RuleAST t) (RULE e int _p (returns int v) (BLOCK (ALT (BLOCK (ALT INT {$v = $INT.int;}) (ALT '(' (= x e) ')' {$v = $x.v;}) (ALT ID)) (* (BLOCK (OPTIONS ...) (ALT {7 >= $_p}? '' (= b e) {$v = $a.v $b.v;}) (ALT {6 >= $_p}? '+' (= b e) {$v = $a.v + $b.v;}) (ALT {3 >= $_p}? '++') (ALT {2 >= $_p}? '--'))))))

setAltASTPointers

back to summary

public void setAltASTPointers(LeftRecursiveRule r, RuleAST t)

 (RULE e int _p (returns int v)
 	(BLOCK
 	  (ALT
 		(BLOCK
 			(ALT INT {$v = $INT.int;})
 			(ALT '(' (= x e) ')' {$v = $x.v;})
 			(ALT ID))
 		(* (BLOCK
			(OPTIONS ...)
 			(ALT {7 >= $_p}? '*' (= b e) {$v = $a.v * $b.v;})
 			(ALT {6 >= $_p}? '+' (= b e) {$v = $a.v + $b.v;})
 			(ALT {3 >= $_p}? '++') (ALT {2 >= $_p}? '--'))))))

translateLeftRecursiveRule	back to summary
public boolean translateLeftRecursiveRule(GrammarRootAST ast, LeftRecursiveRule r, String language) Return true if successful

translateLeftRecursiveRules	back to summary
public void translateLeftRecursiveRules()