/* Lexical Analysis with Flex (1.6.0) We used some of the code from this manual */
/*                                    so we placed the citation here. */
/* definitions */

%option noyywrap

%{ 
#include "typedefs.h" 
%}
        int line_number = 1, column_number = 1;

DIGIT [0-9]
CHAR \\n|\\t|\\'|[^'\n\t\\]
	/* char can be a newline, tab, an escaped quote, or anything but a single quote, an actual line break, an actual tab, or a backslash by itself (to prevent confusion from escaped quote */
SCHAR \\n|\\t|\\\"|[^\"\n\\]  
	/*similar to above, a string Char (SCHAR) is the same as a CHAR except we cannot have double quotes instead of single quotes. Double quotes need to be escaped in Flex unlike single quotes based on documentation */
STARTCOM \(\*
ENDCOM \*\)
COMMENTCHAR [^\*]|\*[^\)]
	/*Making the contents of a comment anything that is either not a * or not a * followed by ) to terminate comments at the first ENDCOM */
%%


\n      line_number++ column_number = 1;
.       column_number++;

"integer"       {return T_INTEGER}
"address"       {return T_ADDRESS}
"Boolean"       {return T_BOOLEAN}
"character"     {return T_CHARACTER}


	/* rules */
{DIGIT}+ {printf( "C_INTEGER: %s (%d)\n", yytext, atoi( yytext ) );}

"null" {printf( "C_NULL: %s (%d)\n", yytext, atoi( yytext ) );}

"while"         {return WHILE}
"if"            {return IF}
"then"          {return THEN}
"else"          {return ELSE}
"type"          {return TYPE}
"function"      {return FUNCTION}
"return"        {return RETURN}
"external"      {return EXTERNAL}
"as"            {return AS}

'{CHAR}' {printf( "C_CHARACTER: %s (%d)\n", yytext, atoi( yytext ) );} /*using double \ per documentation to show escaped chars*/

"true" {printf( "C_TRUE: %s (%d)\n", yytext, atoi( yytext ) );}


"false" {printf( "C_FALSE: %s (%d)\n", yytext, atoi( yytext ) );}

	/* OPERATORS */

"+"		{return ADD;}
"-"		{return SUB_OR_NEG;}
"*"		{return  MUL;}
"/"		{return DIV;}
"%"		{return REM;}
"<"		{return LESS_THAN;}
"="		{return EQUAL_TO;}
":="		{return ASSIGN;}
"!"		{return NOT;}
"&"		{return AND;}
"|"		{return OR;}
"."		{return DOT;}
"reserve"	{return RESERVE;}
"release" 	{return RELEASE;}
 

\"{SCHAR}*\" {printf( "C_STRING: %s (%d)\n", yytext, atoi( yytext ) );}

{STARTCOM}{COMMENTCHAR}*{ENDCOM} {printf( "COMMENT: %s (%d)\n", yytext, atoi( yytext ) );}
 

%%