/* SPDX-License-Identifier: copyleft-next-0.3.1 */
/* Copyright 2023 Kim Kuparinen < kimi.h.kuparinen@gmail.com > */

%option reentrant noyywrap nounput noinput nodefault
%{
#define FROM_LEXER
#include <lyn/parser.h>
#include <lyn/debug.h>

static void update_yylloc(struct parser *parser, YYLTYPE *lloc, const char *text)
{
	(void)parser;

	lloc->first_line = lloc->last_line;
	lloc->first_column = lloc->last_column;

	for (size_t i = 0; text[i] != 0; ++i) {
		if (text[i] == '\n') {
			lloc->last_line++;
			/* flex uses 1 based indexing */
			lloc->last_column = 1;
		} else {
			lloc->last_column++;
		}
	}
}

#define YY_USER_ACTION update_yylloc(parser, yylloc, yytext);
%}
ID		[^(){};\\[:space:]]+
STRING		\"(\\.|[^"\\])*\"

HEX		0[xX][0-9a-fA-F]+
DEC		-?[0-9]+
OCT		0[0-8]+
BIN		0b[0-1]+

INT		{HEX}|{DEC}|{OCT}|{BIN}

HEXF		[+-]?0[xX][0-9a-fA-F]+([pP][+-]?[0-9]+)
DECF		[+-]?[0-9]+[.]([eE]?[+-]?[0-9]+)?[fF]?

FLOAT		{HEXF}|{DECF}

%%
"#".* {/* skip line comments */}

"("	{return LPAREN;}
")"	{return RPAREN;}
"{"	{return LBRACE;}
"}"	{return RBRACE;}
";"	{return SEMICOLON;}
"\\"	{return BACKSLASH;}
"\n"	{return NL;}

{STRING} {
	/* seems risky, I know, but letting the parser choose when to allocate a
	 * new string seems to help with syntax error cleanup */
	yylval->str = strdup(yytext);
	return STRING;
}

{INT} {
	yylval->integer = strtoull(yytext, 0, 0);
	return INT;
}

{FLOAT} {
	yylval->floating = strtod(yytext, 0);
	return FLOAT;
}

{ID} {
	yylval->str = strdup(yytext);
	return ID;
}

[^\n[:graph:]]+	{/* skip whitespace */}

. {
	struct src_issue issue;
	issue.level = SRC_ERROR;
	issue.loc = src_loc(*yylloc);
	issue.fctx.fbuf = parser->buf;
	issue.fctx.fname = parser->fname;
	src_issue(issue, "Unexpected token: %s", yytext);
	parser->failed = true;
}
%%