/*
 *     An example of LEX and YACC working together
 */

letter = [A-Za-z_$];
digit  = [0-9];
white  = [\n\r\t ];

%{
#include "std.h"		/* Standard C conventions */
#include "landy.h"		/* %term definitions from YACC, i.e. -h output file */

char yytext[100];		/* Communication with YACC actions */
int yyival;				/*       "        "    "      "    */
float yyfval;			/*       "        "    "      "    */
%}

%%

letter(letter|digit)*		{gettoken(yytext, sizeof(yytext));
							 printf("LEX/TCON: %s\n", yytext);
							 return(TCON);}

[-]*(digit)*(digit) {{
	        register char *p = yytext; BOOLEAN minus = FALSE;
		gettoken(yytext, sizeof(yytext));
		yyival = 0;
		if(*p == '-') {
		    ++p;
		    minus = TRUE;
		}
		do {
		    if(*p != ',')
			yyival = 10*yyival + (*p - '0');
		} while(*++p);
		if(minus) yyival = -yyival;
	    printf("LEX/ICON: %d\n", yyival);
		return(ICON);
	    }}

[-]*(digit)*"."(digit)* {{
        register char *p = yytext; long decimal = 0; BOOLEAN minus = FALSE;
		gettoken(yytext, sizeof(yytext));
		yyfval = 0.0;
		if(*p == '-') {
		    ++p;
		    minus = TRUE;
		}
		do {
		    switch(*p) {
		    case ',':       break;
		    case '.':       decimal = 10; break;
		    default :       if(!decimal) {
					yyfval = 10. * (yyfval) + (*p - '0');
					break;
				    } else {
					yyfval = yyfval + (*p - '0')/((float) decimal);
					decimal *= 10;
					break;
				    }
		    }
		} while (*++p);
		    if(minus) yyfval = -yyfval;
			printf("LEX/FCON: %f\n", yyfval);
		    return(FCON);
	    }}

white(white)*	{return(LEXSKIP);}

%%

/*
 * Hand-crafted lexgetc to give newline prompt.
 */

lexgetc(){
	static BOOLEAN newline = TRUE;
	register int c;

	if(newline)
	    printf(">");

	if((c = getc(lexin)) == '\n')
	    newline = TRUE;
	else
	    newline = FALSE;	

	return(c);
}