lex

%option noyywrap
%option yylineno

%{

//#include "sym.h"
#include "coma.tab.h"

%}

digit [0-9]
letter [a-zA-Z_]
delim [ \t]
line [\n]
ws {delim}+

%%

ws		{}
line	{}

";"		{ return SEMICOLON; }
var		{ return VAR; }
nil		{ return NIL; }

and		{ return AND; }
or		{ return OR; }
not		{ return NOT; }

","		{ return COMMA; }
"."		{ return DOT; }

"+"		{ return ADD; }
"-"		{ return SUB; }
"*"		{ return MUL; }
"/"		{ return DIV; }
"%"		{ return MOD; }
"^"		{ return POW; }

"="		{ return ASSIGN; }
"+="	{ return ADDASSIGN; }
"-="	{ return SUBASSIGN; }
"*="	{ return MULASSIGN; }
"/="	{ return DIVASSIGN; }
"%="	{ return MODASSIGN; }
"^="	{ return POWASSIGN; }

"++"	{ return DBLADD; }
"--"	{ return DBLSUB; }

"<"		{ return LSS; }
">"		{ return GTR; }
"<="	{ return LEQ; }
">="	{ return GEQ; }
"!="	{ return NEQ; }
"=="	{ return EQL; }
"!"		{ return NOT; }

"("		{ return LP; }
")"		{ return RP; }
"{"		{ return LR; }
"}"		{ return RR; }
"["		{ return LB; }
"]"		{ return RB; }

procedure	{ return PROCEDURE; }
function	{ return FUNCTION; }
return	{ return RETURN; }

begin	{ return BEG; }
end		{ return END; }

if		{ return IF; }
then	{ return THEN; }
else	{ return ELSE; }
elseif	{ return ELSEIF; }

while	{ return WHILE; }
for		{ return FOR; }

in		{ return IN; }
break	{ return BREAK; }
continue	{ return CONTINUE; }

"true"	{ return TRUE; }
"false"	{ return FALSE; }

{letter}({letter}|{digit})* { return IDENTIFIER; }
\"(\\.|[^"])*\"				{ return STRLTR; }
\'.\'						{ return CHRLTR; }
{digit}+(\.{digit}+)*		{ return NUMLTR; }

%%

yacc

%{
#include <stdio.h>
#include <string.h>

extern char* yytext;
extern int yylineno;
 
void yyerror(const char *str)
{
	fprintf(stderr,"error, %s: '%s' in line %d\n", str, yytext, yylineno);
}

%}

%start chunk
%token SEMICOLON VAR NIL AND OR COMMA DOT ADD SUB DIV MUL MOD POW 
%token ADDASSIGN SUBASSIGN DIVASSIGN MULASSIGN MODASSIGN POWASSIGN DBLADD DBLSUB LSS GTR LEQ GEQ NEQ EQL NOT ASSIGN 
%token LP RP LR RR LB RB BEG END IF THEN ELSE ELSEIF FOR WHILE IN BREAK CONTINUE
%token PROCEDURE FUNCTION RETURN IDENTIFIER NUMLTR CHRLTR STRLTR TRUE FALSE

%%

chunk:
	stmts
	;

stmts:
	stmt |
	stmt stmts
	;

stmt:
	SEMICOLON |
	block |
	function_decl |
	procedure_decl |
	return_stmt |
	if_stmt |
	while_stmt |
	for_stmt |
	assign_stmt
	;

block:
	BEG stmts END
	;

function_decl:
	FUNCTION IDENTIFIER LP RP block |
	FUNCTION IDENTIFIER block
	;

procedure_decl:
	PROCEDURE IDENTIFIER LP RP block |
	PROCEDURE IDENTIFIER block
	;

return_stmt:
	RETURN SEMICOLON |
	RETURN expr_list SEMICOLON
	;

while_stmt:
	WHILE expr block
	;

for_stmt:
	FOR IDENTIFIER ASSIGN expr COMMA expr COMMA expr block
	;

if_stmt:
	IF expr THEN stmt END |
	IF expr THEN stmt else_stmt END |
	IF expr THEN stmt elseif_stmt END
	;

else_stmt:
	ELSE stmt
	;

elseif_stmt:
	ELSEIF expr THEN stmt |
	ELSEIF expr THEN stmt elseif_stmt |
	ELSEIF expr THEN stmt else_stmt
	;

expr:
	or_expr
	;

or_expr:
	or_expr OR and_expr |
	and_expr
	;

and_expr:
	and_expr AND cmp_expr |
	cmp_expr
	;

cmp_expr:
	cmp_expr LSS add_expr |
	cmp_expr GTR add_expr |
	cmp_expr LEQ add_expr |
	cmp_expr GEQ add_expr |
	cmp_expr NEQ add_expr |
	cmp_expr EQL add_expr |
	add_expr
	;

add_expr:
	add_expr ADD mul_expr |
	add_expr SUB mul_expr |
	mul_expr
	;

mul_expr:
	mul_expr MUL not_expr |
	mul_expr DIV not_expr |
	mul_expr MOD not_expr |
	not_expr
	;

not_expr:
	not_expr NOT pow_expr |
	SUB pow_expr |
	pow_expr
	;

pow_expr:
	factor POW pow_expr |
	factor
	;

factor:
	NIL |
	FALSE |
	TRUE |
	STRLTR |
	NUMLTR |
	var |
	LP expr RP
	;

expr_list:
	expr |
	expr COMMA expr_list
	;

var_list:
	var |
	var COMMA var_list
	;

var:
	IDENTIFIER |
	var LB expr RB |
	var DOT 
	;

assign_stmt:
	var_list ASSIGN expr_list SEMICOLON
	;

%%