org.antlr.v4.tool

Class GrammarTransformPipeline

java.lang.Object

org.antlr.v4.tool.GrammarTransformPipeline

public class GrammarTransformPipeline
extends Object

Handle left-recursion and block-set transforms

Field Summary

Fields

Modifier and Type	Field and Description
Grammar	g
Tool	tool

Constructor Summary

Constructors

Constructor and Description
GrammarTransformPipeline(Grammar g, Tool tool)

Method Summary

Methods

Modifier and Type	Method and Description
GrammarAST	expandParameterizedLoop(GrammarAST t)
void	expandParameterizedLoops(GrammarAST root) Find and replace ID*[','] with ID (',' ID)* ID+[','] with ID (',' ID)+ (x {action} y)+[','] with x {action} y (',' x {action} y)+ Parameter must be a token.
GrammarRootAST	extractImplicitLexer(Grammar combinedGrammar) Build lexer grammar from combined grammar that looks like: (COMBINED_GRAMMAR A (tokens { X (= Y 'y')) (OPTIONS (= x 'y')) (@ members {foo}) (@ lexer header {package jj;}) (RULES (RULE .+))) Move rules and actions to new tree, don't dup.
void	integrateImportedGrammars(Grammar rootGrammar) Merge all the rules, token definitions, and named actions from imported grammars into the root grammar tree.
void	process()
void	reduceBlocksToSets(GrammarAST root)
static void	setGrammarPtr(Grammar g, GrammarAST tree) Utility visitor that sets grammar ptr in each node

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

g

public Grammar g

tool

public Tool tool

Constructor Detail

GrammarTransformPipeline

public GrammarTransformPipeline(Grammar g,
                        Tool tool)

Method Detail

process

public void process()

reduceBlocksToSets

public void reduceBlocksToSets(GrammarAST root)

expandParameterizedLoops

public void expandParameterizedLoops(GrammarAST root)

Find and replace ID*[','] with ID (',' ID)* ID+[','] with ID (',' ID)+ (x {action} y)+[','] with x {action} y (',' x {action} y)+ Parameter must be a token. todo: do we want?

expandParameterizedLoop

public GrammarAST expandParameterizedLoop(GrammarAST t)

setGrammarPtr

public static void setGrammarPtr(Grammar g,
                 GrammarAST tree)

Utility visitor that sets grammar ptr in each node

integrateImportedGrammars

public void integrateImportedGrammars(Grammar rootGrammar)

Merge all the rules, token definitions, and named actions from imported grammars into the root grammar tree. Perform: (tokens { X (= Y 'y')) + (tokens { Z ) -> (tokens { X (= Y 'y') Z) (@ members {foo}) + (@ members {bar}) -> (@ members {foobar}) (RULES (RULE x y)) + (RULES (RULE z)) -> (RULES (RULE x y z)) Rules in root prevent same rule from being appended to RULES node. The goal is a complete combined grammar so we can ignore subordinate grammars.

extractImplicitLexer

public GrammarRootAST extractImplicitLexer(Grammar combinedGrammar)

Build lexer grammar from combined grammar that looks like: (COMBINED_GRAMMAR A (tokens { X (= Y 'y')) (OPTIONS (= x 'y')) (@ members {foo}) (@ lexer header {package jj;}) (RULES (RULE .+))) Move rules and actions to new tree, don't dup. Split AST apart. We'll have this Grammar share token symbols later; don't generate tokenVocab or tokens{} section. Copy over named actions. Side-effects: it removes children from GRAMMAR & RULES nodes in combined AST. Anything cut out is dup'd before adding to lexer to avoid "who's ur daddy" issues