testinterpretedparsing.java

ANTLR(ANother Tool for Language Recognition)它是这样的一种工具

/*
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 Copyright (c) 2005-2006 Terence Parr
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package org.antlr.test;

import org.antlr.tool.Grammar;
import org.antlr.tool.Interpreter;
import org.antlr.runtime.*;
import org.antlr.runtime.tree.ParseTree;

public class TestInterpretedParsing extends BaseTest {

    /** Public default constructor used by TestRig */
    public TestInterpretedParsing() {
    }

	public void testSimpleParse() throws Exception {
		Grammar pg = new Grammar(
			"parser grammar p;\n"+
			"prog : WHILE ID LCURLY (assign)* RCURLY EOF;\n" +
			"assign : ID ASSIGN expr SEMI ;\n" +
			"expr : INT | FLOAT | ID ;\n");
		Grammar g = new Grammar();
		g.importTokenVocabulary(pg);
		g.setFileName(Grammar.IGNORE_STRING_IN_GRAMMAR_FILE_NAME +"string");
		g.setGrammarContent(
			"lexer grammar t;\n"+
			"WHILE : 'while';\n"+
			"LCURLY : '{';\n"+
			"RCURLY : '}';\n"+
			"ASSIGN : '=';\n"+
			"SEMI : ';';\n"+
			"ID : ('a'..'z')+ ;\n"+
			"INT : (DIGIT)+ ;\n"+
			"FLOAT : (DIGIT)+ '.' (DIGIT)* ;\n"+
			"fragment DIGIT : '0'..'9';\n" +
			"WS : (' ')+ ;\n");
		CharStream input = new ANTLRStringStream("while x { i=1; y=3.42; z=y; }");
		Interpreter lexEngine = new Interpreter(g, input);

		CommonTokenStream tokens = new CommonTokenStream(lexEngine);
		tokens.setTokenTypeChannel(g.getTokenType("WS"), 99);
		//System.out.println("tokens="+tokens.toString());
		Interpreter parseEngine = new Interpreter(pg, tokens);
		ParseTree t = parseEngine.parse("prog");
		String result = t.toStringTree();
		String expecting =
			"(<grammar p> (prog [@0,0:4='while',<4>,1:0] [@2,6:6='x',<5>,1:6] [@4,8:8='{',<6>,1:8] (assign [@6,10:10='i',<5>,1:10] [@7,11:11='=',<8>,1:11] (expr [@8,12:12='1',<10>,1:12]) [@9,13:13=';',<9>,1:13]) (assign [@11,15:15='y',<5>,1:15] [@12,16:16='=',<8>,1:16] (expr [@13,17:20='3.42',<11>,1:17]) [@14,21:21=';',<9>,1:21]) (assign [@16,23:23='z',<5>,1:23] [@17,24:24='=',<8>,1:24] (expr [@18,25:25='y',<5>,1:25]) [@19,26:26=';',<9>,1:26]) [@21,28:28='}',<7>,1:28] [@0,0:0='<no text>',<-1>,0:-1]))";
		assertEquals(result, expecting);
	}

	public void testMismatchedTokenError() throws Exception {
		Grammar pg = new Grammar(
			"parser grammar p;\n"+
			"prog : WHILE ID LCURLY (assign)* RCURLY;\n" +
			"assign : ID ASSIGN expr SEMI ;\n" +
			"expr : INT | FLOAT | ID ;\n");
		Grammar g = new Grammar();
		g.setFileName(Grammar.IGNORE_STRING_IN_GRAMMAR_FILE_NAME +"string");
		g.importTokenVocabulary(pg);
		g.setGrammarContent(
			"lexer grammar t;\n"+
			"WHILE : 'while';\n"+
			"LCURLY : '{';\n"+
			"RCURLY : '}';\n"+
			"ASSIGN : '=';\n"+
			"SEMI : ';';\n"+
			"ID : ('a'..'z')+ ;\n"+
			"INT : (DIGIT)+ ;\n"+
			"FLOAT : (DIGIT)+ '.' (DIGIT)* ;\n"+
			"fragment DIGIT : '0'..'9';\n" +
			"WS : (' ')+ ;\n");
		CharStream input = new ANTLRStringStream("while x { i=1 y=3.42; z=y; }");
		Interpreter lexEngine = new Interpreter(g, input);

		CommonTokenStream tokens = new CommonTokenStream(lexEngine);
		tokens.setTokenTypeChannel(g.getTokenType("WS"), 99);
		//System.out.println("tokens="+tokens.toString());
		Interpreter parseEngine = new Interpreter(pg, tokens);
		ParseTree t = parseEngine.parse("prog");
		String result = t.toStringTree();
		String expecting =
			"(<grammar p> (prog [@0,0:4='while',<4>,1:0] [@2,6:6='x',<5>,1:6] [@4,8:8='{',<6>,1:8] (assign [@6,10:10='i',<5>,1:10] [@7,11:11='=',<8>,1:11] (expr [@8,12:12='1',<10>,1:12]) MismatchedTokenException(5!=9))))";
		assertEquals(result, expecting);
	}

	public void testMismatchedSetError() throws Exception {
		Grammar pg = new Grammar(
			"parser grammar p;\n"+
			"prog : WHILE ID LCURLY (assign)* RCURLY;\n" +
			"assign : ID ASSIGN expr SEMI ;\n" +
			"expr : INT | FLOAT | ID ;\n");
		Grammar g = new Grammar();
		g.importTokenVocabulary(pg);
		g.setFileName("<string>");
		g.setGrammarContent(
			"lexer grammar t;\n"+
			"WHILE : 'while';\n"+
			"LCURLY : '{';\n"+
			"RCURLY : '}';\n"+
			"ASSIGN : '=';\n"+
			"SEMI : ';';\n"+
			"ID : ('a'..'z')+ ;\n"+
			"INT : (DIGIT)+ ;\n"+
			"FLOAT : (DIGIT)+ '.' (DIGIT)* ;\n"+
			"fragment DIGIT : '0'..'9';\n" +
			"WS : (' ')+ ;\n");
		CharStream input = new ANTLRStringStream("while x { i=; y=3.42; z=y; }");
		Interpreter lexEngine = new Interpreter(g, input);

		CommonTokenStream tokens = new CommonTokenStream(lexEngine);
		tokens.setTokenTypeChannel(g.getTokenType("WS"), 99);
		//System.out.println("tokens="+tokens.toString());
		Interpreter parseEngine = new Interpreter(pg, tokens);
		ParseTree t = parseEngine.parse("prog");
		String result = t.toStringTree();
		String expecting =
			"(<grammar p> (prog [@0,0:4='while',<4>,1:0] [@2,6:6='x',<5>,1:6] [@4,8:8='{',<6>,1:8] (assign [@6,10:10='i',<5>,1:10] [@7,11:11='=',<8>,1:11] (expr MismatchedSetException(9!={5, 10..11})))))";
		assertEquals(result, expecting);
	}

	public void testNoViableAltError() throws Exception {
		Grammar pg = new Grammar(
			"parser grammar p;\n"+
			"prog : WHILE ID LCURLY (assign)* RCURLY;\n" +
			"assign : ID ASSIGN expr SEMI ;\n" +
			"expr : {;}INT | FLOAT | ID ;\n");
		Grammar g = new Grammar();
		g.importTokenVocabulary(pg);
		g.setFileName("<string>");
		g.setGrammarContent(
			"lexer grammar t;\n"+
			"WHILE : 'while';\n"+
			"LCURLY : '{';\n"+
			"RCURLY : '}';\n"+
			"ASSIGN : '=';\n"+
			"SEMI : ';';\n"+
			"ID : ('a'..'z')+ ;\n"+
			"INT : (DIGIT)+ ;\n"+
			"FLOAT : (DIGIT)+ '.' (DIGIT)* ;\n"+
			"fragment DIGIT : '0'..'9';\n" +
			"WS : (' ')+ ;\n");
		CharStream input = new ANTLRStringStream("while x { i=; y=3.42; z=y; }");
		Interpreter lexEngine = new Interpreter(g, input);

		CommonTokenStream tokens = new CommonTokenStream(lexEngine);
		tokens.setTokenTypeChannel(g.getTokenType("WS"), 99);
		//System.out.println("tokens="+tokens.toString());
		Interpreter parseEngine = new Interpreter(pg, tokens);
		ParseTree t = parseEngine.parse("prog");
		String result = t.toStringTree();
		String expecting =
			"(<grammar p> (prog [@0,0:4='while',<4>,1:0] [@2,6:6='x',<5>,1:6] [@4,8:8='{',<6>,1:8] (assign [@6,10:10='i',<5>,1:10] [@7,11:11='=',<8>,1:11] (expr NoViableAltException(9!=[4:1: expr : ( INT | FLOAT | ID );])))))";
		assertEquals(result, expecting);
	}

}