#include <wchar.h>
#include <wctype.h>

#if 0
static const unsigned char tab0[] = {0};
static const unsigned char tab1[] = {0};
static const unsigned char tab2[] = {0};

static const unsigned char rulebases[512] = {0};
static const int rules[] = {0};

static const unsigned char exceptions[][2] = {0};
#else
extern const unsigned char tab0[];
extern const unsigned char tab1[];
extern const unsigned char tab2[];

extern const unsigned char rulebases[512];
extern const int rules[];

extern const unsigned char exceptions[][2];
#endif

static int casing_delta(unsigned c, int dir)
{
	unsigned b, x, y, v, rt, xb, xn;
	int r, rd;

	if (c >= 0x20000) return 0;

	b = c>>8;
	c &= 255;
	x = c>>3;
	y = c&7;
	v = (tab0[tab0[b]*32+x]>>y&1)
	  + (tab1[tab1[b]*32+x]>>y&1)*2
	  + (tab2[tab2[b]*32+x]>>y&1)*4;

	/* use the bit vector out of the tables as an index into
	 * a block-specific set of rules and decode the rule into
	 * a type and a case-mapping delta. */
	r = rules[rulebases[b]+v];
	rt = r & 255;
	rd = r >> 8;

	/* rules 0/1 are simple lower/upper case with a delta.
	 * apply according to desired mapping direction. */
	if (rt < 2) return rd & -(rt^dir);

	/* binary search. endpoints of the binary search for
	 * this block are stored in the rule delta field. */
	xn = rd & 0xff;
	xb = (unsigned)rd >> 8;
	while (xn) {
		unsigned try = exceptions[xb+xn/2][0];
		if (try == c) {
			r = rules[exceptions[xb+xn/2][1]];
			rt = r & 255;
			rd = r >> 8;
			if (rt < 2) return rd & -(rt^dir);
			/* Hard-coded for the four exceptional titlecase */
			return dir ? -1 : 1;
		} else if (try > c) {
			xn /= 2;
		} else {
			xb += xn/2;
			xn -= xn/2;
		}
	}
	return 0;
}

wint_t towlower(wint_t wc)
{
	return wc + casing_delta(wc, 0);
}

wint_t towupper(wint_t wc)
{
	return wc + casing_delta(wc, 1);
}