/***********************************************************************

*                                                                      *

*               This software is part of the ast package               *

*          Copyright (c) 1985-2011 AT&T Intellectual Property          *

*                      and is licensed under the                       *

*                 Eclipse Public License, Version 1.0                  *

*                    by AT&T Intellectual Property                     *

*                                                                      *

*                A copy of the License is available at                 *

*          http://www.eclipse.org/org/documents/epl-v10.html           *

*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *

*                                                                      *

*              Information and Software Systems Research               *

*                            AT&T Research                             *

*                           Florham Park NJ                            *

*                                                                      *

*                 Glenn Fowler <gsf@research.att.com>                  *

*                  David Korn <dgk@research.att.com>                   *

*                   Phong Vo <kpv@research.att.com>                    *

*                                                                      *

***********************************************************************/

#pragma prototyped

/*

 * Glenn Fowler

 * AT&T Research

 *

 * return an Sfio_t* to a file or string that

 *

 *	splices \\n to single lines

 *	checks for "..." and '...' spanning newlines

 *	drops #...\n comments

 *

 * if <arg> is a file and first line matches

 *	#!!! <level> <message> !!!

 * then error(<lev>,"%s: %s",<arg>,<msg>) called

 *

 * NOTE: seek disabled and string disciplines cannot be composed

 *	 quoted \n translated to \r

 */

#include <ast.h>

#include <error.h>

#include <tok.h>

typedef struct

{

	Sfdisc_t	disc;

	Sfio_t*		sp;

	int		quote;

	int*		line;

} Splice_t;

/*

 * the splicer

 */

static int

spliceline(Sfio_t* s, int op, void* val, Sfdisc_t* ad)

{

	Splice_t*	d = (Splice_t*)ad;

	register char*	b;

	register int	c;

	register int	n;

	register int	q;

	register int	j;

	register char*	e;

	char*		buf;

	NoP(val);

	switch (op)

	{

	case SF_CLOSING:

		sfclose(d->sp);

		return 0;

	case SF_DPOP:

		free(d);

		return 0;

	case SF_READ:

		do

		{

			if (!(buf = sfgetr(d->sp, '\n', 0)) && !(buf = sfgetr(d->sp, '\n', -1)))

				return 0;

			n = sfvalue(d->sp);

			q = d->quote;

			j = 0;

			(*d->line)++;

			if (n > 1 && buf[n - 2] == '\\')

			{

				j = 1;

				n -= 2;

				if (q == '#')

				{

					n = 0;

					continue;

				}

			}

			else if (q == '#')

			{

				q = 0;

				n = 0;

				continue;

			}

			if (n > 0)

			{

				e = (b = buf) + n;

				while (b < e)

				{

					if ((c = *b++) == '\\')

						b++;

					else if (c == q)

						q = 0;

					else if (!q)

					{

						if (c == '\'' || c == '"')

							q = c;

						else if (c == '#' && (b == (buf + 1) || (c = *(b - 2)) == ' ' || c == '\t'))

						{

							if (buf[n - 1] != '\n')

							{

								q = '#';

								n = b - buf - 2;

							}

							else if (n = b - buf - 1)

								buf[n - 1] = '\n';

							break;

						}

					}

				}

				if (n > 0)

				{

					if (!j && buf[n - 1] != '\n' && (s->_flags & SF_STRING))

						buf[n++] = '\n';

					if (q && buf[n - 1] == '\n')

						buf[n - 1] = '\r';

				}

			}

		} while (n <= 0);

		sfsetbuf(s, buf, n);

		d->quote = q;

		return 1;

	default:

		return 0;

	}

}

/*

 * open a stream to parse lines

 *

 *	flags: 0		arg: open Sfio_t* 

 *	flags: SF_READ		arg: file name

 *	flags: SF_STRING	arg: null terminated char*

 *

 * if line!=0 then it points to a line count that starts at 0

 * and is incremented for each input line

 */

Sfio_t*

tokline(const char* arg, int flags, int* line)

{

	Sfio_t*		f;

	Sfio_t*		s;

	Splice_t*	d;

	char*		p;

	char*		e;

	static int	hidden;

	if (!(d = newof(0, Splice_t, 1, 0)))

		return 0;

	if (!(s = sfopen(NiL, NiL, "s")))

	{

		free(d);

		return 0;

	}

	if (!(flags & (SF_STRING|SF_READ)))

		f = (Sfio_t*)arg;

	else if (!(f = sfopen(NiL, arg, (flags & SF_STRING) ? "s" : "r")))

	{

		free(d);

		sfclose(s);

		return 0;

	}

	else if ((p = sfreserve(f, 0, 0)) && sfvalue(f) > 11 && strmatch(p, "#!!! +([-0-9]) *([!\n]) !!!\n*") && (e = strchr(p, '\n')))

	{

		flags = strtol(p + 5, &p, 10);

		error(flags, "%s:%-.*s", arg, e - p - 4, p);

	}

	d->disc.exceptf = spliceline;

	d->sp = f;

	*(d->line = line ? line : &hidden) = 0;

	sfdisc(s, (Sfdisc_t*)d);

	return s;

}