//_ aApply.d
// Copyright (c) 2004 by Digital Mars
// Written by Walter Bright

/* This code handles decoding UTF strings for foreach loops.
 * There are 6 combinations of conversions between char, wchar,
 * and dchar, and 2 of each of those.
 */

import std.utf;

//debug=apply;

/**********************************************
 * 'apply' for associative arrays - to support foreach
 */

// dg is D, but _aApplycd() is C
extern (D) typedef int delegate(void *) dg_t;

extern (C) int _aApplycd1(char[] aa, dg_t dg)
{   int result;
    size_t i;
    size_t len = aa.length;

    debug(apply) printf("_aApplycd1(), len = %d\n", len);
    for (i = 0; i < len; )
    {	dchar d;

	d = aa[i];
	if (d & 0x80)
	    d = std.utf.decode(aa, i);
	else
	    i++;
	result = dg(cast(void *)&d);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplywd1(wchar[] aa, dg_t dg)
{   int result;
    size_t i;
    size_t len = aa.length;

    debug(apply) printf("_aApplywd1(), len = %d\n", len);
    for (i = 0; i < len; )
    {	dchar d;

	d = aa[i];
	if (d & ~0x7F)
	    d = std.utf.decode(aa, i);
	else
	    i++;
	result = dg(cast(void *)&d);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplycw1(char[] aa, dg_t dg)
{   int result;
    size_t i;
    size_t len = aa.length;

    debug(apply) printf("_aApplycw1(), len = %d\n", len);
    for (i = 0; i < len; )
    {	dchar d;
	wchar w;

	w = aa[i];
	if (w & 0x80)
	{   d = std.utf.decode(aa, i);
	    if (d <= 0xFFFF)
		w = cast(wchar) d;
	    else
	    {
		w = (((d - 0x10000) >> 10) & 0x3FF) + 0xD800;
		result = dg(cast(void *)&w);
		if (result)
		    break;
		w = ((d - 0x10000) & 0x3FF) + 0xDC00;
	    }
	}
	else
	    i++;
	result = dg(cast(void *)&w);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplywc1(wchar[] aa, dg_t dg)
{   int result;
    size_t i;
    size_t len = aa.length;

    debug(apply) printf("_aApplywc1(), len = %d\n", len);
    for (i = 0; i < len; )
    {	dchar d;
	wchar w;
	char c;

	w = aa[i];
	if (w & ~0x7F)
	{
	    char[4] buf;
	    char[] b;

	    d = std.utf.decode(aa, i);
	    b = std.utf.toUTF8(buf, d);
	    foreach (char c; b)
	    {
		result = dg(cast(void *)&c);
		if (result)
		    return result;
	    }
	    continue;
	}
	else
	{   c = cast(char)w;
	    i++;
	}
	result = dg(cast(void *)&c);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplydc1(dchar[] aa, dg_t dg)
{   int result;

    debug(apply) printf("_aApplydc1(), len = %d\n", aa.length);
    foreach (dchar d; aa)
    {
	char c;

	if (d & ~0x7F)
	{
	    char[4] buf;
	    char[] b;

	    b = std.utf.toUTF8(buf, d);
	    foreach (char c; b)
	    {
		result = dg(cast(void *)&c);
		if (result)
		    return result;
	    }
	    continue;
	}
	else
	{
	    c = cast(char)d;
	}
	result = dg(cast(void *)&c);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplydw1(dchar[] aa, dg_t dg)
{   int result;

    debug(apply) printf("_aApplydw1(), len = %d\n", aa.length);
    foreach (dchar d; aa)
    {
	wchar w;

	if (d <= 0xFFFF)
	    w = cast(wchar) d;
	else
	{
	    w = (((d - 0x10000) >> 10) & 0x3FF) + 0xD800;
	    result = dg(cast(void *)&w);
	    if (result)
		break;
	    w = ((d - 0x10000) & 0x3FF) + 0xDC00;
	}
	result = dg(cast(void *)&w);
	if (result)
	    break;
    }
    return result;
}


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

// dg is D, but _aApplycd2() is C
extern (D) typedef int delegate(void *, void *) dg2_t;

extern (C) int _aApplycd2(char[] aa, dg2_t dg)
{   int result;
    size_t i;
    size_t n;
    size_t len = aa.length;

    debug(apply) printf("_aApplycd2(), len = %d\n", len);
    for (i = 0; i < len; i += n)
    {	dchar d;

	d = aa[i];
	if (d & 0x80)
	{
	    n = i;
	    d = std.utf.decode(aa, n);
	    n -= i;
	}
	else
	    n = 1;
	result = dg(&i, cast(void *)&d);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplywd2(wchar[] aa, dg2_t dg)
{   int result;
    size_t i;
    size_t n;
    size_t len = aa.length;

    debug(apply) printf("_aApplywd2(), len = %d\n", len);
    for (i = 0; i < len; i += n)
    {	dchar d;

	d = aa[i];
	if (d & ~0x7F)
	{
	    n = i;
	    d = std.utf.decode(aa, n);
	    n -= i;
	}
	else
	    n = 1;
	result = dg(&i, cast(void *)&d);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplycw2(char[] aa, dg2_t dg)
{   int result;
    size_t i;
    size_t n;
    size_t len = aa.length;

    debug(apply) printf("_aApplycw2(), len = %d\n", len);
    for (i = 0; i < len; i += n)
    {	dchar d;
	wchar w;

	w = aa[i];
	if (w & 0x80)
	{   n = i;
	    d = std.utf.decode(aa, n);
	    n -= i;
	    if (d <= 0xFFFF)
		w = cast(wchar) d;
	    else
	    {
		w = (((d - 0x10000) >> 10) & 0x3FF) + 0xD800;
		result = dg(&i, cast(void *)&w);
		if (result)
		    break;
		w = ((d - 0x10000) & 0x3FF) + 0xDC00;
	    }
	}
	else
	    n = 1;
	result = dg(&i, cast(void *)&w);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplywc2(wchar[] aa, dg2_t dg)
{   int result;
    size_t i;
    size_t n;
    size_t len = aa.length;

    debug(apply) printf("_aApplywc2(), len = %d\n", len);
    for (i = 0; i < len; i += n)
    {	dchar d;
	wchar w;
	char c;

	w = aa[i];
	if (w & ~0x7F)
	{
	    char[4] buf;
	    char[] b;

	    n = i;
	    d = std.utf.decode(aa, n);
	    n -= i;
	    b = std.utf.toUTF8(buf, d);
	    foreach (char c; b)
	    {
		result = dg(&i, cast(void *)&c);
		if (result)
		    return result;
	    }
	    continue;
	}
	else
	{   c = cast(char)w;
	    n = 1;
	}
	result = dg(&i, cast(void *)&c);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplydc2(dchar[] aa, dg2_t dg)
{   int result;
    size_t i;
    size_t len = aa.length;

    debug(apply) printf("_aApplydc2(), len = %d\n", len);
    for (i = 0; i < len; i++)
    {	dchar d;
	char c;

	d = aa[i];
	if (d & ~0x7F)
	{
	    char[4] buf;
	    char[] b;

	    b = std.utf.toUTF8(buf, d);
	    foreach (char c; b)
	    {
		result = dg(&i, cast(void *)&c);
		if (result)
		    return result;
	    }
	    continue;
	}
	else
	{   c = cast(char)d;
	}
	result = dg(&i, cast(void *)&c);
	if (result)
	    break;
    }
    return result;
}

extern (C) int _aApplydw2(dchar[] aa, dg2_t dg)
{   int result;

    debug(apply) printf("_aApplydw2(), len = %d\n", aa.length);
    foreach (size_t i, dchar d; aa)
    {
	wchar w;

	if (d <= 0xFFFF)
	    w = cast(wchar) d;
	else
	{
	    w = (((d - 0x10000) >> 10) & 0x3FF) + 0xD800;
	    result = dg(&i, cast(void *)&w);
	    if (result)
		break;
	    w = ((d - 0x10000) & 0x3FF) + 0xDC00;
	}
	result = dg(&i, cast(void *)&w);
	if (result)
	    break;
    }
    return result;
}