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lexer.flex
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lexer.flex
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/*
* This is the lexer for compiler by using Jflex
* And it will be good used by Jcup
to Create the lexer.java
> jflex lexer.flex
*/
/* --------------------------Usercode Section------------------------ */
import java_cup.runtime.*;
import java.io.*;
import java.util.*;
%%
/* -----------------Options and Declarations Section----------------- */
/*
The name of the class JFlex will create will be Lexer.
Will write the code to the file lexer.java.
*/
%class lexer
%unicode
%line
%column
/*
Will switch to a CUP compatibility mode to interface with a CUP
generated parser.
*/
%cup
%{
StringBuffer string = new StringBuffer();
private Symbol symbol(int type) {
return new Symbol(type, yyline, yycolumn);
}
private Symbol symbol(int type, Object value) {
return new Symbol(type, yyline, yycolumn, value);
}
%}
/*WhiteSpace*/
LineTerminator = \r|\n|\r\n
InputCharacter = [^\r\n]
WhiteSpace = {LineTerminator}|[ \t\f]
/*Comments*/
Comment = {OneLineComment} | {IncludeComment} | {TraditionalComment} | {DocumentationComment}
TraditionalComment = "/*" [^*] ~"*/" | "/*" "*"+ "/"
DocumentationComment = "/*" "*"+ [^/*] ~"*/"
IncludeComment = #[^"\n"]*"\n"
OneLineComment = "//"[^"\n"]*{LineTerminator}?
/*Constants*/
Identifier = [a-zA-Z_$][a-zA-Z_$0-9]*
Constint = 0[0-7]*|0[xX][0-9a-fA-F]+|[1-9][0-9]*
Constchar = '([^\n']|\\')+'
Conststr = \"([^\n\r\"]|\\\")*\"
%%
/* ------------------------Lexical Rules Section---------------------- */
<YYINITIAL> "void" {return symbol(sym.VOID);}
<YYINITIAL> "char" {return symbol(sym.CHAR);}
<YYINITIAL> "int" {return symbol(sym.INT);}
<YYINITIAL> "struct" {return symbol(sym.STRUCT);}
<YYINITIAL> "union" {return symbol(sym.UNION);}
<YYINITIAL> "if" {return symbol(sym.IF);}
<YYINITIAL> "else" {return symbol(sym.ELSE);}
<YYINITIAL> "while" {return symbol(sym.WHILE);}
<YYINITIAL> "for" {return symbol(sym.FOR);}
<YYINITIAL> "continue" {return symbol(sym.CONTINUE);}
<YYINITIAL> "break" {return symbol(sym.BREAK);}
<YYINITIAL> "return" {return symbol(sym.RETURN);}
<YYINITIAL> "sizeof" {return symbol(sym.SIZEOF);}
<YYINITIAL> {
/*Ignorance*/
{Comment} {/*ignore*/}
{WhiteSpace} {/*ignore*/}
/*Constants*/
{Identifier} {return symbol(sym.ID, yytext());}
{Constint} {return symbol(sym.CONSTINT, yytext());}
{Constchar} {return symbol(sym.CONSTCHAR, yytext());}
{Conststr} {return symbol(sym.CONSTSTR, yytext());}
/*Keywords*/
"*=" {return symbol(sym.MUL_ASSIGN);}
"/=" {return symbol(sym.DIV_ASSIGN);}
"%=" {return symbol(sym.MOD_ASSIGN);}
"+=" {return symbol(sym.ADD_ASSIGN);}
"-=" {return symbol(sym.SUB_ASSIGN);}
"<<=" {return symbol(sym.SHL_ASSIGN);}
">>=" {return symbol(sym.SHR_ASSIGN);}
"&=" {return symbol(sym.AND_ASSIGN);}
"^=" {return symbol(sym.XOR_ASSIGN);}
"|=" {return symbol(sym.OR_ASSIGN);}
"||" {return symbol(sym.OR_L);}
"&&" {return symbol(sym.AND_L);}
"==" {return symbol(sym.EQ);}
"!=" {return symbol(sym.NE);}
"<=" {return symbol(sym.LE);}
">=" {return symbol(sym.GE);}
"<<" {return symbol(sym.SHL);}
">>" {return symbol(sym.SHR);}
"++" {return symbol(sym.INC);}
"--" {return symbol(sym.DEC);}
"->" {return symbol(sym.PTR);}
/*Op*/
"(" {return symbol(sym.LPA);}
")" {return symbol(sym.RPA);}
";" {return symbol(sym.SEMI);}
"," {return symbol(sym.COMMA);}
"=" {return symbol(sym.EVA);}
"{" {return symbol(sym.LCU);}
"}" {return symbol(sym.RCU);}
"[" {return symbol(sym.LSQ);}
"]" {return symbol(sym.RSQ);}
"|" {return symbol(sym.OR);}
"^" {return symbol(sym.XOR);}
"&" {return symbol(sym.AND);}
"<" {return symbol(sym.LT);}
">" {return symbol(sym.GT);}
"+" {return symbol(sym.ADD);}
"-" {return symbol(sym.SUB);}
"*" {return symbol(sym.MUL);}
"/" {return symbol(sym.DIV);}
"%" {return symbol(sym.MOD);}
"~" {return symbol(sym.COM);}
"!" {return symbol(sym.NOT);}
"." {return symbol(sym.DOT);}
}
/* others */
[^] {throw new Error("Illegal character<"+yytext()+">");}