%{
/* This file is part of Eclat.
   Copyright (C) 2012-2018 Sergey Poznyakoff.
 
   Eclat is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.
 
   Eclat is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with Eclat.  If not, see <http://www.gnu.org/licenses/>. */

#include "libeclat.h"
#include <sysexits.h>
#include <ctype.h>
#include <grecs.h>
#include <grecs/locus.h>
#include "forlangrm.h"
#include "forlan.h"

static const char *forlan_input_base;
static size_t forlan_input_len;
static size_t forlan_input_pos;

#undef YY_INPUT
#define YY_INPUT(buf,result,max_size)					\
	do {								\
		if (forlan_input_base) {				\
			size_t __s = forlan_input_len - forlan_input_pos; \
			if (__s > max_size)				\
				__s = max_size;				\
			if (__s > 0) {					\
				memcpy(buf, forlan_input_base, __s);	\
				forlan_input_pos += __s;		\
			}						\
			result = __s;					\
		} else							\
			result = fread(buf, 1, max_size, yyin);		\
	} while(0)

#define YY_USER_ACTION do {						\
		if (YYSTATE == 0) {					\
			yylloc.beg = grecs_current_locus_point;		\
			yylloc.beg.col++;				\
		}							\
  		grecs_current_locus_point.col += yyleng;		\
 		yylloc.end = grecs_current_locus_point;			\
   	} while (0);

static int yywrap(void);

%}

%option noinput
%option nounput

WS [ \t\f][ \t\f]*
ID [a-zA-Z_][a-zA-Z_0-9-]*
%x COMMENT ML STR
%%
         /* Comments */
"/*"         BEGIN(COMMENT);
<COMMENT>[^*\n]*        /* eat anything that's not a '*' */
<COMMENT>"*"+[^*/\n]*   /* eat up '*'s not followed by '/'s */
<COMMENT>\n          grecs_locus_point_advance_line(grecs_current_locus_point);
<COMMENT>"*"+"/"     BEGIN(INITIAL);
"//".*               ;
         /* Decimal numbers */
-?[0-9][0-9]*         { grecs_line_begin();
                        grecs_line_add(yytext, yyleng);
                        yylval.string = grecs_line_finish();
	                return STRING; }
         /* Keywords */ 
if                    return IF;
else                  return ELSE;
last                  return LAST;
for                   return FOR;
let                   return LET;
in                    return IN;
break                 return BREAK;
continue              return CONTINUE;
!                     return NOT;
"&&"                  return AND;
"||"                  return OR;
"=="                  return EQ;
"!="                  return NE;
{ID}                  { grecs_line_begin();
                        grecs_line_add(yytext, yyleng);
                        yylval.string = grecs_line_finish();
	                return IDENT; }
         /* Quoted strings */
\"[^\\"\n]*\"         { grecs_line_begin();
                        grecs_line_add(yytext + 1, yyleng - 2);
                        yylval.string = grecs_line_finish();
                        return STRING; }
\"[^\\"\n]*\\\n        { BEGIN(STR);
                         grecs_line_begin();
		         grecs_line_acc_grow_unescape_last(yytext + 1,
                                                           yyleng - 1,
							   &yylloc);
                         grecs_locus_point_advance_line(grecs_current_locus_point); }
\"[^\\"\n]*\\.         { BEGIN(STR);
                         grecs_line_begin();
		         grecs_line_acc_grow_unescape_last(yytext + 1,
                                                           yyleng - 1,
                                                           &yylloc); }
<STR>\"[^\\"\n]*\\\n  { grecs_line_acc_grow_unescape_last(yytext, yyleng,
							  &yylloc);
                        grecs_locus_point_advance_line(grecs_current_locus_point); }
<STR>[^\\"\n]*\\.     { grecs_line_acc_grow_unescape_last(yytext, yyleng, &yylloc); }
<STR>[^\\"\n]*\"      { BEGIN(INITIAL);
                        if (yyleng > 1) 
				grecs_line_add(yytext, yyleng - 1); 
                        yylval.string = grecs_line_finish();
		        return STRING; }
         /* Other tokens */
{WS}     ;
\n       { grecs_locus_point_advance_line(grecs_current_locus_point); } 
[.,;{}()\[\]=\*%] return yytext[0];
.        { if (isascii(yytext[0]) && isprint(yytext[0]))
		grecs_error(&yylloc, 0,
			     _("stray character %c"), yytext[0]);
           else
		grecs_error(&yylloc, 0,
			     _("stray character \\%03o"),
			       (unsigned char) yytext[0]); }
%%

static int
yywrap()
{
	return 1;
}

void
forlan_lex_from_buffer(const char *input, size_t length,
		       struct grecs_locus_point *pt)
{
	forlan_input_base = input;
	forlan_input_len = length;
	grecs_current_locus_point = *pt;
	yy_flex_debug = debug_level(forlan_dbg) >= FORLAN_DBG_LEX;
	grecs_line_acc_create();
}

void
forlan_lex_from_file(FILE *fp, struct grecs_locus_point *pt)
{
	yyin = fp;
	forlan_input_base = NULL;
	grecs_current_locus_point = *pt;
	yy_flex_debug = debug_level(forlan_dbg) >= FORLAN_DBG_LEX;
	grecs_line_acc_create();
}

void
forlan_lex_end()
{
	grecs_line_acc_free();
}