Sample lex file

svg.lm

%{
#import <Foundation/Foundation.h>
#import <stdlib.h>
#import "SVGBase.h"
#import "SVGLength.h"
#import "SVGAngle.h"
#import "y.tab.h"
void yyerror(char *);
%}

%%
^"length"                {   return LENGTH; }
^"angle"                 {   return ANGLE; }
^"color"                 {   return COLOR; }
[:]                     {   return SEMICOLON; }

[#][0-9A-Fa-f]{3}([0-9A-Fa-f]{3})? { /* Hexadecimal */
    size_t length = strlen(yytext);
    char hexadecimal[7]="000000";
    int i = 0;
    for (;i < 6;i++) hexadecimal[i]=yytext[(length ==4 ? i/2 : i) + 1];
    yylval.integerValue = strtol(hexadecimal, NULL, 16);
    return HEXADECIMAL; }

[+-]?[0-9]+             {   yylval.integerValue = atoi(yytext); return INTEGER;}
[+-]?[0-9]*[.][0-9]+    {   yylval.integerValue = atof(yytext); return FLOAT; }

em|ex|px|cm|mm|in|pt|pc {   
        NSString *key = [NSString stringWithCString:yytext 
                                           encoding:NSUTF8StringEncoding];
        NSNumber *lengthType = [SVGLengthTypeDict objectForKey:key];
        yylval.lengthTypeValue = [lengthType intValue];
        return LENGTHTYPE; 
    }

deg|rad|grad            {   
        NSString *key = [NSString stringWithCString:yytext 
                                         encoding:NSUTF8StringEncoding];
        NSNumber *angleType = [SVGAngleTypeDict objectForKey:key];
        yylval.angleTypeValue = [angleType intValue];
        return ANGLETYPE; 
}

[\n]                    {   return *yytext; }

  .                     yyerror("Unknown character");

%%

int yywrap(void) {
    return 1;
}

svg.ym

%{
#import <Foundation/Foundation.h>
#import <stdio.h>
#import "SVGBase.h"
#import "SVGAngle.h"
#import "SVGLength.h"

int yylex(void);
void yyerror(char *);
void* yy_scan_string(const char*);
NSObject *yyvalue;

%}

%union {
    SVGFloat        floatValue;
    SVGInteger      integerValue;
    SVGLengthType   lengthTypeValue;
    SVGAngleType    angleTypeValue;
    char*           stringPtr;
    char            charValue;
    NSObject*       objectPtr;
};

%token SEMICOLON LENGTH ANGLE COLOR 
%token <integerValue>       INTEGER
%token <floatValue>         FLOAT
%token <lengthTypeValue>    LENGTHTYPE
%token <angleTypeValue>     ANGLETYPE
%token <integerValue>       HEXADECIMAL


%type  <objectPtr>          length
%type  <lengthTypeValue>    lengthType
%type  <objectPtr>          angle
%type  <angleTypeValue>     angleType
%type  <objectPtr>          value
%type  <floatValue>         number
%type  <integerValue>       color

%%

//program:
//            program value '\n'  { NSLog(AT"%@\n", $2); }
//            | /* empty */
//            ;

value:      length              {yyvalue=$1;}
            | angle             {yyvalue=$1;}
            | color             {yyvalue=[NSNumber numberWithLong:$1];}
            ;

number:     INTEGER             {$$=(float)$1;}
            | FLOAT             {$$=(float)$1;}
            ;

lengthType: LENGTHTYPE          
            | /* empty */       {$$=SVGLengthTypeNumber;}
            ;

length:     LENGTH
            SEMICOLON
            number lengthType   {$$=[SVGLength lengthWithValue:$3 unit:$4];}
            ;

angleType:  ANGLETYPE
            | /* empty */       {$$=SVGAngleTypeUnspecified;}
            ;

angle:      ANGLE
            SEMICOLON
            number angleType    {$$=[SVGAngle angleWithValue:$3 unit:$4];}
            ;

color:      COLOR
            SEMICOLON
            HEXADECIMAL         {$$=$3;}
            ;

%%

void yyerror(char *s) {
    fprintf(stderr, "%s\n", s);
}

int main(int argc, char**argv) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    //yy_scan_string("color(#AABBCC)");
    yy_scan_string(argv[1]);
    yyparse();
    NSLog(@"%@\n", yyvalue);
    return 0;
    [pool release];
}