%{
#import <Foundation/Foundation.h>
#import <AppKit/AppKit.h>

#import "SchemeTypes.h"

#define YYSTYPE id

#include "scheme.tab.m.h"

int yyinputline;
char *yyinputstr, *yyinputstart;
int yysofar;

#define YY_INPUT(buf,result,max_size) \
   { \
   int c = *yyinputstr++; \
   result = (!c) ? YY_NULL : (buf[0] = c, 1); \
   }
%}

SIGN         "+"|"-"
DIGIT        [0-9]
FRAC         "."{DIGIT}+
EXPONENT     {SIGN}?[eE]{SIGN}?{DIGIT}+
LETTER       [a-zA-Z]
SYMEXTRA     [-+*/><=!?]
SYMSPECIAL   ">="|"<="

STRING       "\""([^\n\"\\]|"\\\\"|"\\\"")*"\""

%%

";".[^\n]*$ { /* skip comments */
    yyinputline++;
    yysofar += yyleng;
}

"'" {
    yysofar += yyleng; return QUOTECHAR;
}

"=>" {
    yysofar += yyleng; return ARROW;
}

"quote" {
    yysofar += yyleng; return QUOTE;
}

"call-with-current-continuation" {
    yysofar += yyleng; return CALLCC;
}

"apply" {
    yysofar += yyleng; return APPLY;
}

"define" {
    yysofar += yyleng; return DEFINE;
}

"set!" {
    yysofar += yyleng; return SET;
}

"lambda" {
    yysofar += yyleng; return LAMBDA;
}

"if" {
    yysofar += yyleng; return IF;
}

"begin" {
    yysofar += yyleng; return BEGINTOK;
}

"and" {
    yysofar += yyleng; return AND;
}

"or" {
    yysofar += yyleng; return OR;
}

"case" {
    yysofar += yyleng; return CASE;
}

"cond" {
    yysofar += yyleng; return COND;
}

"else" {
    yysofar += yyleng; return ELSE;
}

"let" {
    yysofar += yyleng; return LET;
}

"let*" {
    yysofar += yyleng; return LETSTAR;
}

"letrec" {
    yysofar += yyleng; return LETREC;
}

"#"[tf] {
    BOOL val = (yytext[1]=='t' ? YES : NO);
    yylval = [[Boolean alloc] initSCMBoolean:val];
    yysofar += yyleng; return BOOLEAN;
}

"#\\"("newline"|"space"|"tab"|[^\n\t ]) {
    char val;
    if(!strcmp(yytext, "#\\newline")){
        val = '\n';
    }
    else if(!strcmp(yytext, "#\\tab")){
        val = '\t';
    }
    else if(!strcmp(yytext, "#\\space")){
        val = ' ';
    }
    else{
        val = yytext[2];
    }

    yylval = [[Char alloc] initSCMChar:val];
    yysofar += yyleng; return CHAR;
}

{SIGN}?{DIGIT}*{FRAC} {
    double val;
    sscanf(yytext, "%le", &val);
    yylval = [[Double alloc] initSCMDouble:val];
    yysofar += yyleng; return DOUBLE;
}

{SIGN}?{DIGIT}+"." {
    double val;
    sscanf(yytext, "%le", &val);
    yylval = [[Double alloc] initSCMDouble:val];
    yysofar += yyleng; return DOUBLE;
}

{SIGN}?{DIGIT}+{EXPONENT} {
    double val;
    sscanf(yytext, "%le", &val);
    yylval = [[Double alloc] initSCMDouble:val];
    yysofar += yyleng; return DOUBLE;
}

{SIGN}?{DIGIT}*{FRAC}{EXPONENT} {
    double val;
    sscanf(yytext, "%le", &val);
    yylval = [[Double alloc] initSCMDouble:val];
    yysofar += yyleng; return DOUBLE;
}

{SIGN}?{DIGIT}+ {
    long int val;
    sscanf(yytext, "%ld", &val);
    yylval = [[Int alloc] initSCMInt:val];
    yysofar += yyleng; return INTEGER;
}

{SYMSPECIAL}|{SYMEXTRA} {
    yylval = [[Symbol alloc] initSCMSymbol:yytext];
    yysofar += yyleng; return SYMBOL;
}


{LETTER}({LETTER}|{DIGIT}|{SYMEXTRA}|"?"|"*")* {
    yylval = [[Symbol alloc] initSCMSymbol:yytext];
    yysofar += yyleng; return SYMBOL;
}

{STRING} {
    yylval = [[String alloc] initSCMStringLEX:yytext];
    yysofar += yyleng; return STRING;
}

"#(" {
    yysofar += yyleng; return LVECTPAREN;
}

"(" {
    yysofar += yyleng; return LPAREN;
}
    
")" {
    yysofar += yyleng; return RPAREN;
}

"." {
    yysofar += yyleng; return DOT;
}

[ \t]+          yysofar += yyleng; /* eat up whitespace */

"\n"            yysofar += yyleng; yyinputline++;
    
. printf( "Unrecognized character: %s\n", yytext); yysofar += yyleng;

%%