%{
#include <stdio.h>
extern int yylval;
extern int symcount;
extern int strcount;
typedef struct {
  char mysymbol[20];
  int value;} SYMBOL_TBL;

char str_tbl[100][80];
SYMBOL_TBL sym_tbl[100];
#include "y.tab.h"
int x;
%}

letter [A-Za-z]
digit  [0-9]

ident  {letter}({letter}|{digit})*
op    "+"|"-"|"*"|"/"|"("|")"|";"|"<"|">"
ws    [ \t\n]+
other .

%%
{ws}    ;
"if"    { return IF;}
"then"  { return THEN;}
"else"  { return ELSE;}
"while" { return WHILE;}
"do"    { return DO; }
"print" { return PRINT;}
"endif" { return ENDIF;}
"endwhile" { return ENDWHILE;}
"read"  { return READ;}
">="    { return GE;}
"<="    { return LE;}

\".*\" { 
           yylval = installs(yytext);
              return STR;}
"newline" { return NEWLINE; }
{ident} {
         yylval = install(yytext,0);
         return ID;
        }
{op}    return yytext[0];

{digit}+ {
         sscanf(yytext,"%d",&x);
         yylval = install(yytext,x);
          return NUM;
         }
"=="   return EQEQ;
"="    return ASSIGN;


.       return yytext[0];

%%

int install(char *ident, int val)
{
 int i;
 i = 1;
 while ((i <= symcount) && strcmp(ident, sym_tbl[i].mysymbol)) 
 i++;
 if (i <= symcount) return i;
 else 
  {
   symcount++;
   strcpy(sym_tbl[symcount].mysymbol,ident);
   sym_tbl[symcount].value = val;
   return symcount;
  }
}

int installs(char *val)
{
 int j,i;
 char x[80];
  for (j=1;j<strlen(val)-1;j++)
    x[j-1] = val[j];
    x[strlen(val)-2] ='\0';
/*  printf("String %s\n", x); */
 strcpy(str_tbl[++strcount],x);
 for(i=0;i<80;i++) x[i] =' ';
 return strcount;
}