/* 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
%option header-file="flex.h"
%{
#include "typedefs.h"
int line_number = 1, column_number = 1;
%}

COM ([^*]|\*+[^)*])*
ID [A-Za-z_][0-9A-Za-z_]*
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 */

%%

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

{DIGIT}+        {return C_INTEGER;}
"null"          {return C_NULL;}

"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}'        {return C_CHARACTER;}
"true"          {return C_TRUE;}
"false"         {return C_FALSE;}

"+"		        {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;}

";"             {return SEMI_COLON;}
":"             {return COLON;}
","             {return COMMA;}
"->"            {return ARROW;}

"reserve"	    {return RESERVE;}
"release" 	    {return RELEASE;}

\"{SCHAR}*\"    {return C_STRING;}
"(*"{COM}"*)"   {return COMMENT;}

{ID}            {return ID;}

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

%%