%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "lex.h"


//Symbol table (implemented as linked list)
list_head_t* head;


%}

/* Definitions */
delim	[ \t\n]
ws		{delim}+
id		[A-Za-z][A-Za-z0-9]*
num		[0-9]+
real	[0-9]*\.[0-9]*
basic   int|float
com		(("//".*\n)|("/*".*"*/"))

%%
{ws}	{}
{com}	{}
"if"	{yylval=NULL;					/*printf("lex:\tif\n",yytext);*/return (IF);}
"else"	{yylval=NULL;					/*printf("lex:\telse\n",yytext);*/return (ELSE);}
"while"	{yylval=NULL;					/*printf("lex:\twhile\n",yytext);*/return (WHILE);}
"do"	{yylval=NULL;					/*printf("lex:\tdo\n",yytext);*/return (DO);}
"break"	{yylval=NULL;					/*printf("lex:\tbreak\n",yytext);*/return (BREAK);}
{basic}	{if(strcmp(yytext, "int") == 0)
			yylval = (void*) &int_var;
		else yylval = (void*) &float_var;
										/*printf("lex:\tbasic\\n",yylval)*/;return (BASIC);}
"true"	{yylval=(void *)&true_var;		/*printf("lex:\t%s\n",yytext);*/return (BOOL);}
"false"	{yylval=(void *)&false_var;		/*printf("lex:\t%s\n",yytext);*/return (BOOL);}
{id}	{yylval=(void *)installID();	/*printf("lex:\tid\n");*/return (ID);}
{num}	{yylval=(void *)parseNum();		/*printf("lex:\tnum\n");*/return (NUM);}
{real}	{yylval=(void *)parseReal();	/*printf("lex:\treal\n");*/return (REAL);}
"<="	{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (LE);}
"<"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (LT);}
">="	{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (GE);}
">"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (GT);}
"=="	{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (EQUALTO);}
"!="	{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (NOTEQUAL);}
"("		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (OPENPAREN);}
")"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (CLOSEPAREN);}
"]"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (CLOSEBRACKET);}
"["		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (OPENBRACKET);}
"}"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (CLOSEBRACE);}
"{"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (OPENBRACE);}
"&&"	{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (AND);}
"||"	{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (OR);}
";"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (SEMI);}
"+"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (PLUS);}
"-"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (MINUS);}
"*"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (MULTI);}
"/"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (DIV);}
"!"		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (NOT);}
"="		{yylval=NULL;					/*printf("lex:\t%s\n",yytext);*/return (EQUALS);}
%%

//If id is not already in symbol table, insert. Return pointer to symbol table entry
void* installID(){
	//printf("install id: %s\n",yytext);
	char* key=calloc(strlen(yytext),sizeof(char));
	//Copy token to key
	strcpy(key, yytext);
	//printf("Token key: %s\n",key);
	//search for key
	list_entry_t* entry=list_search_entry(head, key);
	//If key doesn't exist, add it to symbol table and return entry pointer
	if(entry==NULL)
		return (void*)list_insert(head, key, NULL);
	//Else return pointer to existing entry
	return (void*)entry;
}

//Parse integer from code at yytext
void* parseNum(){
	int* i=malloc(sizeof(int));
	*i=atoi(yytext);
	return (void*)i;
}

//Parse float from code at yytext
void* parseReal(){
	float* r=malloc(sizeof(float));;
	*r=atof(yytext);
	return (void*)r;
}

int yywrap(){return 1;}

//Used for searching table
int cmp_string( const void *a, const void *b)
{
	assert(a!=NULL);
	assert(b!=NULL);
	return strcmp(a,b);
}