程序要求能自动生成AST抽象语法树。
Lab3Main.java
package sch.cauc.edu.token;
import edu.ustc.cs.compile.platform.interfaces.InterRepresent;
/**
*
*
* Lab3Main
* 创建人:xrzhang
* 时间：2018年5月25日-上午8:13:05
* @version 1.0.0
*
*/
public class Lab3Main {
public static void main(String[] args) {
//String srcFileName="test/expr3.txt";
//String srcFileName="test/expr221.txt";
String srcFileName="test/expr222.txt";
//String srcFileName="test/testown.txt";
SyntaxDirectedTranslation parser=new SyntaxDirectedTranslation();
InterRepresent ir=parser.doParse(srcFileName);
ir.showIR();
}
}
SyntaxDirectedTranslation.java
package sch.cauc.edu.token;
import java.util.LinkedList;
import org.eclipse.jdt.core.dom.*;
import edu.ustc.cs.compile.platform.interfaces.InterRepresent;
import edu.ustc.cs.compile.util.ir.HIRPack;
public class SyntaxDirectedTranslation {
/*抽象语法树的根节点*/
private AST ast=null;
private BlockLexer lexer=null;
private Token lookAhead=null;
public SyntaxDirectedTranslation() {
ast = AST.newAST(AST.JLS3);
}
public InterRepresent doParse(String filePath){
lexer=new BlockLexer(filePath);
Block mainBody = this.parse();
HIRPack ir = new HIRPack();
ir.setIR(mainBody);
return ir;
}
public Token matchToken(TokenType type,String functionName){
if(lookAhead.getType()!=type){
parsingError(type.toString(),functionName);
}
Token matchedSymbol = lookAhead;
lookAhead = lexer.nextToken();
return matchedSymbol;
}
public void parsingError(String types,String functionName){
System.out.println("Parsing Error! in"+functionName);
System.out.println("encounter "+lookAhead.getLexeme());
System.out.println("at line "+lookAhead.getLine()+",column "+lookAhead.getColumn());
System.out.println("while expecting "+types);
System.exit(1);
}
/**
*
* 调用开始符号对应的方法，进行语法分析
* 方法名：parse
* 创建人：xrzhang
* 时间：2018年5月16日-上午10:27:14
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
public Block parse() {
System.out.println("In parse();-----jmzhang-----");
lookAhead=lexer.nextToken();
Block mainBody=simpleblock();
System.out.println("Parsing Success!");
return mainBody;
}
/**
*
* simpleblock = LBRACE sequence RBRACE
* B->{S}
* 方法名：simpleblock
* 创建人：xrzhang
* 时间：2018年5月19日-下午6:59:57
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
public Block simpleblock() {
System.out.println("In simpleblock();-----jmzhang-----");
if(lookAhead.getType()==TokenType.LBRACKET){
matchToken(TokenType.LBRACKET, "simpleblock");
System.out.println("***********{*********");
LinkedList seq =sequence();
matchToken(TokenType.RBRACKET, "simpleblock");
System.out.println("***********}*********");
Block mainBody=ast.newBlock();
if (seq!=null) {
for(int i=0;i<seq.size();i++){
mainBody.statements().add(seq.get(i));
}
}
return mainBody;
}else{
parsingError(TokenType.LBRACKET.toString(), "simpleblock");
return null;
}
}
/**
*
* sequence=assognmentStatement sequence |
* ifStatement sequence |
* whileStatement sequence |
* epsilon
* S->AS | IS |WS | ε
* 方法名：Sequence
* 创建人：xrzhang
* 时间：2018年5月16日-下午8:54:23
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private LinkedList sequence() {
System.out.println("In Sequence();-----jmzhang-----");
if(lookAhead.getType()==TokenType.IDENTIFIER){
ExpressionStatement es=assignmentStatement();
LinkedList seq=sequence();
if (seq==null) {
seq=new LinkedList();
}
seq.addFirst(es);
return seq;
}else if (lookAhead.getType()==TokenType.KEY_IF) {
IfStatement es=ifStatement();
LinkedList seq=sequence();
if (seq==null) {
seq=new LinkedList();
}
seq.addFirst(es);
return seq;
}else if (lookAhead.getType()==TokenType.KEY_WHILE) {
System.out.println("In Sequence();-----jmzhang-----WHILE");
WhileStatement es=whileStatement();
LinkedList seq=sequence();
if (seq==null) {
seq=new LinkedList();
}
seq.addFirst(es);
return seq;
}else if (lookAhead.getType()==TokenType.RBRACKET) {
//match epslon
return null;
}else {
String errorTypes=TokenType.IDENTIFIER.toString()+","+TokenType.RBRACKET.toString();
parsingError(errorTypes, "sequence");
return null;
}
}
/************************************>
* @return ************************************/
private WhileStatement whileStatement() {
System.out.println("In whileStatement();-----jmzhang-----");
if (lookAhead.getType()==TokenType.KEY_WHILE) {
matchToken(TokenType.KEY_WHILE, "whileStatement");
WhileStatement wStatement=ast.newWhileStatement();
System.out.println("***********while*********");
matchToken(TokenType.LPAREN, "whileStatement");
System.out.println("***********(*********");
Expression be=Boolexpression();
wStatement.setExpression(be);
matchToken(TokenType.RPAREN, "whileStatement");
System.out.println("***********)*********");
matchToken(TokenType.LBRACKET, "whileStatement");
System.out.println("***********{*********");
Block ifbody=ast.newBlock();
LinkedList seq =sequence();
if (seq!=null) {
for(int i=0;i<seq.size();i++){
ifbody.statements().add(seq.get(i));
}
}
wStatement.setBody(ifbody);
matchToken(TokenType.RBRACKET, "whileStatement");
System.out.println("***********}*********");
/*if (seq!=null) {
for(int i=0;i<seq.size();i++){
mainBody.statements().add(seq.get(i));
}
}*/
return wStatement;
}else {
String errorTypes=TokenType.KEY_WHILE.toString();
parsingError(errorTypes, "whileStatement");
return null;
}
}
/**
*
*
* 方法名：Boolexpression
* 创建人：xrzhang
* 时间：2018年5月19日-下午8:58:23
* 邮件：jmzhang_15_cauc@163.com
* @return Expression
* @exception
* @since 1.0.0
*/
private Expression Boolexpression() {
System.out.println("In Boolexpression();-----jmzhang-----");
if (lookAhead.getType()==TokenType.BOOL_TRUE
||lookAhead.getType()==TokenType.BOOL_FALSE
||lookAhead.getType()==TokenType.LPAREN
||lookAhead.getType()==TokenType.IDENTIFIER
||lookAhead.getType()==TokenType.INTEGER_LITERAL) {
InfixExpression infix=ast.newInfixExpression();
Expression left=Boolterm();
Expression right=Boolexpression_1(left);
return right;
}else {
String errorTypes =TokenType.BOOL_TRUE.toString()
+","+TokenType.BOOL_FALSE.toString()
+","+TokenType.LPAREN.toString()
+","+TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString();
parsingError(errorTypes, "Boolexpression");
return null;
}
}
/**
*
* 方法名：Boolexpression_1
* 创建人：xrzhang
* 时间：2018年5月19日-下午9:02:26
* 邮件：jmzhang_15_cauc@163.com
* @param left
* @return Expression
* @exception
* @since 1.0.0
*/
private Expression Boolexpression_1(Expression left) {
System.out.println("In Boolexpression_1();-----jmzhang-----");
if (lookAhead.getType()==TokenType.LOGICAL_OR) {
matchToken(TokenType.LOGICAL_OR, "Boolexpression_1");
System.out.println("***********||*********");
Expression right=Boolterm();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression e=Boolexpression_1(infixEx);
return e;
}else if (lookAhead.getType()==TokenType.RPAREN) {
//match epslin
//follow(E')={')',','}
return left;
}else {
String errorTypes =TokenType.LOGICAL_OR.toString()
+","+TokenType.RPAREN.toString();
parsingError(errorTypes, "Boolexpression_1");
return null;
}
}
/**
*
* 方法名：Boolterm
* 创建人：xrzhang
* 时间：2018年5月19日-下午9:03:36
* 邮件：jmzhang_15_cauc@163.com
* @return Expression
* @exception
* @since 1.0.0
*/
private Expression Boolterm() {
System.out.println("In Boolterm();-----jmzhang-----");
if(lookAhead.getType()==TokenType.BOOL_TRUE
||lookAhead.getType()==TokenType.BOOL_FALSE
||lookAhead.getType()==TokenType.LPAREN
||lookAhead.getType()==TokenType.IDENTIFIER
||lookAhead.getType()==TokenType.INTEGER_LITERAL){
Expression f=Boolfactor();
Expression t=Boolterm_1(f);
return t;
}else {
String errorTypes =TokenType.BOOL_TRUE.toString()
+","+TokenType.BOOL_FALSE.toString()
+","+TokenType.LPAREN.toString()
+","+TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString();
parsingError(errorTypes, "Boolterm");
return null;
}
}
/**
*
* 方法名：Boolterm_1
* 创建人：xrzhang
* 时间：2018年5月19日-下午9:08:20
* 邮件：jmzhang_15_cauc@163.com
* @param left
* @return Expression
* @exception
* @since 1.0.0
*/
private Expression Boolterm_1(Expression left) {
System.out.println("In Boolterm_1();-----jmzhang-----");
if (lookAhead.getType()==TokenType.LOGICAL_AND) {
matchToken(TokenType.LOGICAL_AND, "Boolterm_1");
System.out.println("***********&&*********");
Expression right=Boolfactor();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setOperator(InfixExpression.Operator.AND);
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression t=Boolterm_1(infixEx);
return t;
}else if (lookAhead.getType()==TokenType.LOGICAL_OR
||lookAhead.getType()==TokenType.RPAREN) {
//match e[slion
//follow(T')={'+','-',')',',')
return left;
}else {
String errorTypes =TokenType.LOGICAL_AND.toString()
+","+TokenType.LOGICAL_OR.toString()
+","+TokenType.RPAREN.toString();
parsingError(errorTypes, "Boolterm_1");
return null;
}
}
private Expression Boolfactor() {
System.out.println("In Boolfactor();-----jmzhang-----");
if (lookAhead.getType()==TokenType.BOOL_TRUE) {
Token id=matchToken(TokenType.BOOL_TRUE, "Boolfactor");
System.out.println("***********true*********");
SimpleName sn=ast.newSimpleName(id.getLexeme());
return sn;
}else if (lookAhead.getType()==TokenType.BOOL_FALSE) {
Token num=matchToken(TokenType.BOOL_FALSE, "Boolfactor");
System.out.println("***********flase*********");
NumberLiteral nl=ast.newNumberLiteral(num.getLexeme());
return nl;
}else if (lookAhead.getType()==TokenType.LPAREN||
lookAhead.getType()==TokenType.IDENTIFIER||
lookAhead.getType()==TokenType.INTEGER_LITERAL){
Expression r=relationlExpression();
return r;
}else {
String errorTypes =TokenType.BOOL_TRUE.toString()
+","+TokenType.BOOL_FALSE.toString()
+","+TokenType.LPAREN.toString()
+","+TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString();
parsingError(errorTypes, "relationlExpressionOperator");
return null;
}
}
private Expression relationlExpression() {
System.out.println("In relationlExpression();-----jmzhang-----");
if (lookAhead.getType()==TokenType.LPAREN||
lookAhead.getType()==TokenType.IDENTIFIER||
lookAhead.getType()==TokenType.INTEGER_LITERAL) {
InfixExpression infix=ast.newInfixExpression();
Expression left=expression();
infix.setLeftOperand(left);
//Expression r=relationlExpressionOperator();
infix.setOperator(relationlExpressionOperator());
Expression right=expression();
infix.setRightOperand(right);
return infix;
}else {
String errorTypes =TokenType.LPAREN.toString()
+","+TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString();
parsingError(errorTypes, "relationlExpression");
return null;
}
}
private InfixExpression.Operator relationlExpressionOperator() {
System.out.println("In relationlExpressionOperator();-----jmzhang-----");
if (lookAhead.getType()==TokenType.LESS) {
matchToken(TokenType.LESS, "relationlExpressionOperator");
System.out.println("***********<*********");
return InfixExpression.Operator.LESS;
}else if (lookAhead.getType()==TokenType.GREATER) {
matchToken(TokenType.GREATER, "relationlExpressionOperator");
System.out.println("***********>*********");
return InfixExpression.Operator.GREATER;
}else if (lookAhead.getType()==TokenType.LESS_EQUAL) {
matchToken(TokenType.LESS_EQUAL, "relationlExpressionOperator");
System.out.println("***********<=*********");
return InfixExpression.Operator.LESS_EQUALS;
}else if (lookAhead.getType()==TokenType.GREATER_EQUAL) {
matchToken(TokenType.GREATER_EQUAL, "relationlExpressionOperator");
System.out.println("***********>=*********");
return InfixExpression.Operator.GREATER_EQUALS;
}else if (lookAhead.getType()==TokenType.NOT_EQUAL) {
matchToken(TokenType.NOT_EQUAL, "relationlExpressionOperator");
System.out.println("***********!=*********");
return InfixExpression.Operator.NOT_EQUALS;
}else if(lookAhead.getType()==TokenType.EQUAL) {
matchToken(TokenType.EQUAL, "relationlExpressionOperator");
System.out.println("***********==*********");
return InfixExpression.Operator.EQUALS;
}else {
String errorTypes =TokenType.LESS.toString()
+","+TokenType.GREATER.toString()
+","+TokenType.LESS_EQUAL.toString()
+","+TokenType.GREATER_EQUAL.toString()
+","+TokenType.NOT_EQUAL.toString()
+","+TokenType.EQUAL.toString();
parsingError(errorTypes, "relationlExpressionOperator");
return null;
}
}
private IfStatement ifStatement() {
System.out.println("In ifStatement();-----jmzhang-----");
if (lookAhead.getType()==TokenType.KEY_IF) {
matchToken(TokenType.KEY_IF, "ifStatement");
IfStatement is = ast.newIfStatement();
System.out.println("***********if*********");
matchToken(TokenType.LPAREN, "ifStatement");
System.out.println("***********(*********");
Expression be=Boolexpression();
is.setExpression(be);
matchToken(TokenType.RPAREN, "ifStatement");
System.out.println("***********)*********");
matchToken(TokenType.LBRACKET, "ifStatement");
System.out.println("***********{*********");
Block ifbody=ast.newBlock();
LinkedList seq =sequence();
if (seq!=null) {
for(int i=0;i<seq.size();i++){
ifbody.statements().add(seq.get(i));
}
}
is.setThenStatement(ifbody);
matchToken(TokenType.RBRACKET, "ifStatement");
System.out.println("***********}*********");
if(lookAhead.getType()==TokenType.KEY_ELSE)
{
Block o=OptionalElse();
is.setElseStatement(o);
}
return is;
}else {
String errorTypes=TokenType.KEY_IF.toString();
parsingError(errorTypes, "ifStatement");
return null;
}
}
private Block OptionalElse() {
System.out.println("In OptionalElse();-----jmzhang-----");
if(lookAhead.getType()==TokenType.KEY_ELSE){
System.out.println("In OptionalElse();-----jmzhang-----1");
matchToken(TokenType.KEY_ELSE, "OptionalElse");
IfStatement elIfStatement =ast.newIfStatement();
System.out.println("***********else*********");
matchToken(TokenType.LBRACKET, "OptionalElse");
System.out.println("***********{*********");
Block ifbody=ast.newBlock();
LinkedList seq =sequence();
if (seq!=null) {
for(int i=0;i<seq.size();i++){
ifbody.statements().add(seq.get(i));
}
}
matchToken(TokenType.RBRACKET, "OptionalElse");
System.out.println("***********}*********");
return ifbody;
}else if (lookAhead.getType()==TokenType.RBRACKET
||lookAhead.getType()==TokenType.KEY_IF
||lookAhead.getType()==TokenType.KEY_WHILE
||lookAhead.getType()==TokenType.IDENTIFIER) {
//match epslion
return null;
}else {
String errorTypes =TokenType.KEY_ELSE.toString()
+","+TokenType.RBRACKET.toString()
+","+TokenType.KEY_IF.toString()
+","+TokenType.KEY_WHILE.toString()
+","+TokenType.IDENTIFIER.toString();
parsingError(errorTypes, "OptionalElse");
return null;
}
}
/*************************************<**********************************/
/**
*
* assignmentStatement =IDENTIFIER ASSIGN expression SEMICOLON
* A->id = E;
* 方法名：assignmentStatement
* 创建人：xrzhang
* 时间：2018年5月16日-下午8:56:26
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private ExpressionStatement assignmentStatement() {
System.out.println("In assignmentStatement();-----jmzhang-----");
if (lookAhead.getType()==TokenType.IDENTIFIER) {
Token id =matchToken(TokenType.IDENTIFIER, "assignmentStatement");
System.out.println("***********id*********");
matchToken(TokenType.ASSIGN, "assignmentStatement");
System.out.println("***********=*********");
Expression e=expression();
matchToken(TokenType.SEMICOLON, "assignmentStatement");
System.out.println("***********;*********");
SimpleName sn=ast.newSimpleName(id.getLexeme());
Assignment assign=ast.newAssignment();
assign.setLeftHandSide(sn);
assign.setOperator(Assignment.Operator.ASSIGN);
assign.setRightHandSide(e);
ExpressionStatement es=ast.newExpressionStatement(assign);
return es;
}else {
String errorTypes=TokenType.IDENTIFIER.toString();
parsingError(errorTypes, "assignmentStatement");
return null;
}
}
/**
*
* expression = term expression_1
* E->TE'
* 方法名：expression
* 创建人：xrzhang
* 时间：2018年5月16日-下午9:00:40
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private Expression expression() {
System.out.println("In expression();-----jmzhang-----");
if (lookAhead.getType()==TokenType.IDENTIFIER
||lookAhead.getType()==TokenType.LPAREN
||lookAhead.getType()==TokenType.INTEGER_LITERAL) {
Expression left=term();
Expression right=expression_1(left);
return right;
}else {
String errorTypes =TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString()
+","+TokenType.LPAREN.toString();
parsingError(errorTypes, "expression");
return null;
}
}
/**
*
* expression_1=PLUS term expression_1 | MINUS term expression_1 | epslin
* E'->TE' | -TE' | ε
* 方法名：expression_1
* 创建人：xrzhang
* 时间：2018年5月16日-下午9:06:26
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private Expression expression_1(Expression left) {
System.out.println("In expression_1();-----jmzhang-----");
if (lookAhead.getType()==TokenType.PLUS) {
matchToken(TokenType.PLUS, "expression_1");
System.out.println("***********+*********");
Expression right=term();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression e=expression_1(infixEx);
return e;
}else if (lookAhead.getType()==TokenType.MINUS) {
matchToken(TokenType.MINUS, "expression_1");
System.out.println("***********-*********");
Expression right=term();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setOperator(InfixExpression.Operator.MINUS);
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression e=expression_1(infixEx);
return e;
}else if (lookAhead.getType()==TokenType.SEMICOLON
||lookAhead.getType()==TokenType.LESS
||lookAhead.getType()==TokenType.GREATER
||lookAhead.getType()==TokenType.LESS_EQUAL
||lookAhead.getType()==TokenType.GREATER_EQUAL
||lookAhead.getType()==TokenType.NOT_EQUAL
||lookAhead.getType()==TokenType.EQUAL
||lookAhead.getType()==TokenType.LOGICAL_AND
||lookAhead.getType()==TokenType.LOGICAL_OR
||lookAhead.getType()==TokenType.RPAREN) {
System.out.println("In expression_1();-----jmzhang-----follow");
//match epslin
//follow(E')={')',','}
return left;
}else {
System.out.println("In expression_1();-----jmzhang-----else");
String errorTypes =TokenType.PLUS.toString()
+","+TokenType.MINUS.toString()
+","+TokenType.SEMICOLON.toString()
+","+TokenType.LESS.toString()
+","+TokenType.GREATER.toString()
+","+TokenType.LESS_EQUAL.toString()
+","+TokenType.GREATER_EQUAL.toString()
+","+TokenType.NOT_EQUAL.toString()
+","+TokenType.EQUAL.toString();
parsingError(errorTypes, "expression_1");
return null;
}
}
/**
*
* term=factor term_1
* T->FT'
* 方法名：term
* 创建人：xrzhang
* 时间：2018年5月16日-下午9:16:51
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private Expression term() {
System.out.println("In term();-----jmzhang-----");
if(lookAhead.getType()==TokenType.IDENTIFIER
||lookAhead.getType()==TokenType.LPAREN
||lookAhead.getType()==TokenType.INTEGER_LITERAL){
Expression f=factor();
Expression t=term_1(f);
return t;
}else {
String errorTypes =TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString()
+","+TokenType.LPAREN.toString();
parsingError(errorTypes, "term");
return null;
}
}
/**
*
* term_1=MULT factor term_1 | DIV factor term_1 | MOD factor term_1 | epslin
* T'->*FT' | /FT' |%FT'|ε
* 方法名：term_1
* 创建人：xrzhang
* 时间：2018年5月16日-下午9:20:00
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private Expression term_1(Expression left) {
System.out.println("In term_1();-----jmzhang-----");
if (lookAhead.getType()==TokenType.TIMES) {
matchToken(TokenType.TIMES, "term_1");
System.out.println("***********乘*********");
Expression right=factor();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setOperator(InfixExpression.Operator.TIMES);
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression t=term_1(infixEx);
return t;
}else if (lookAhead.getType()==TokenType.DIVIDE) {
matchToken(TokenType.DIVIDE, "term_1");
System.out.println("***********/*********");
Expression right=factor();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setOperator(InfixExpression.Operator.DIVIDE);
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression t=term_1(infixEx);
return t;
}else if (lookAhead.getType()==TokenType.REMAINDER) {
matchToken(TokenType.REMAINDER, "term_1");
System.out.println("***********%*********");
Expression right=factor();
InfixExpression infixEx=ast.newInfixExpression();
infixEx.setOperator(InfixExpression.Operator.REMAINDER);
infixEx.setLeftOperand(left);
infixEx.setRightOperand(right);
Expression t=term_1(infixEx);
return t;
}else if (lookAhead.getType()==TokenType.PLUS
||lookAhead.getType()==TokenType.MINUS
||lookAhead.getType()==TokenType.RPAREN
||lookAhead.getType()==TokenType.SEMICOLON
||lookAhead.getType()==TokenType.LESS
||lookAhead.getType()==TokenType.GREATER
||lookAhead.getType()==TokenType.LESS_EQUAL
||lookAhead.getType()==TokenType.GREATER_EQUAL
||lookAhead.getType()==TokenType.NOT_EQUAL
||lookAhead.getType()==TokenType.EQUAL
||lookAhead.getType()==TokenType.LOGICAL_AND
||lookAhead.getType()==TokenType.LOGICAL_OR
||lookAhead.getType()==TokenType.RPAREN) {
//match e[slion
//follow(T')={'+','-',')',',')
return left;
}else {
String errorTypes =TokenType.TIMES.toString()
+","+TokenType.DIVIDE.toString()
+","+TokenType.REMAINDER.toString()
+","+TokenType.PLUS.toString()
+","+TokenType.MINUS.toString()
+","+TokenType.SEMICOLON.toString()
+","+TokenType.LESS.toString()
+","+TokenType.GREATER.toString()
+","+TokenType.LESS_EQUAL.toString()
+","+TokenType.GREATER_EQUAL.toString()
+","+TokenType.NOT_EQUAL.toString()
+","+TokenType.EQUAL.toString()
+","+TokenType.LOGICAL_AND.toString()
+","+TokenType.LOGICAL_OR.toString();
parsingError(errorTypes, "term_1");
return null;
}
}
/**
*
* factor = LPAREN expression RPAREN | IDENTIFER|INTEGER_LITERAL
* F->(E)|id| number
* 方法名：factor
* 创建人：xrzhang
* 时间：2018年5月16日-下午9:29:47
* 邮件：jmzhang_15_cauc@163.com void
* @exception
* @since 1.0.0
*/
private Expression factor() {
System.out.println("In factor();-----jmzhang-----");
if (lookAhead.getType()==TokenType.LPAREN) {
matchToken(TokenType.LPAREN, "factor");
System.out.println("***********（*********");
Expression e=expression();
matchToken(TokenType.RPAREN, "factor");
System.out.println("***********）*********");
ParenthesizedExpression pe=ast.newParenthesizedExpression();
pe.setExpression(e);
return pe;
}else if (lookAhead.getType()==TokenType.IDENTIFIER) {
Token id=matchToken(TokenType.IDENTIFIER, "factor");
System.out.println("***********id*********");
SimpleName sn=ast.newSimpleName(id.getLexeme());
return sn;
}else if (lookAhead.getType()==TokenType.INTEGER_LITERAL) {
Token num=matchToken(TokenType.INTEGER_LITERAL, "factor");
System.out.println("***********int*********");
NumberLiteral nl=ast.newNumberLiteral(num.getLexeme());
return nl;
}else {
String errorTypes =TokenType.LPAREN.toString()
+","+TokenType.IDENTIFIER.toString()
+","+TokenType.INTEGER_LITERAL.toString();
parsingError(errorTypes, "factor");
return null;
}
}
}
测试文件expr3.txt
{
i1=14;
i2=i1+2*3;
i3=i1-5*(i2%2)+5;
}
测试文件expr221.txt
{
i1=14;
i2=i1+2*3;
i3=i1-5*(i2%2)+5;
if(4<5){}
if(i1==i4&&i2>=20){
i3=i3+1;}
else{
i3=i3+2;}
}
测试文件expr222.txt
{
m=12;n=21;
if(m<n){
t=m;m=n;n=t;
}
r=1;
d=m%n;
while(r!=0){m=n;n=r;r=m%n;}
}