%{
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "y.tab.h"
#include "lahari.h"

extern int lineno;
struct _Symbol *new_symbol();

%}

letter   [a-zA-Z_@]
digit    [0-9]
sign     [-+]
integer  {sign}?{digit}+
decreal  ([0-9]*"."[0-9]+)
decexp   ([0-9]*"."[0-9]+[eE][+-]?[0-9]+)
real     {sign}?({decreal}|{decexp})

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

identifier {letter}[a-zA-Z0-9_@]*
         
whitespace [ \t\f\x1a]

nl        \n


%%

{whitespace}+    ; 

{integer}        { 
                    Symbol *sym;
                    sym = new_symbol();
                    sym->ival = atoi(yytext);
                    sym->type = NUMBER;
                    yylval.sym = sym;
                    return NUMBER;
                 }


{real}           { 
                    struct _Symbol *sym;
                    sym = new_symbol();
                    sym->dval = atof(yytext);
                    sym->type = NUMBER;
                    yylval.sym = sym;
                    return NUMBER;
		 }

{qstring}        { yylval.sval=strdup(yytext);return STRING; }

{nl}             { return *yytext; } 

;                { return *yytext; }

[-()=+*/.^]      {
                   return *yytext;
                 }

and              {
                   return BOOL_AND;
                 }

or               {
                   return BOOL_OR;
                 }

"=="             {
                   return TEST_EQ;
                 }

"!="             {
                   return TEST_NE;
                 }

">"              {
                   return TEST_GT;
                 }

"<"              {
                   return TEST_LT;
                 }

while            {
                   return WHILE;
                 }

if               {
                   return IF;
                 }

else             {
                   return ELSE;
                 }

do               {
                  return DO;
                 }         

then             {
                  return THEN;
                 }

end              {
                  return END;
                 }

int              {
                  return TYPE_INT;
                 }

double           {
                  return TYPE_REAL;
                 }

string           {
                  return TYPE_STR;
                 }

{identifier}     { 
                    struct _Symbol *sym;
                    sym = new_symbol();
                    sym->sval = strdup(yytext);
                    sym->type = IDENT;
                    yylval.sym = sym;
                    return IDENT;
                 }
                  

%%


struct _Symbol *new_symbol()
{
  Symbol *sym;
  sym = (Symbol*)calloc(1, sizeof(Symbol));
  return sym;
}