Пример #1
0
DUK_LOCAL duk_ret_t duk__construct_from_codepoints(duk_context *ctx, duk_bool_t nonbmp) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_bufwriter_ctx bw_alloc;
	duk_bufwriter_ctx *bw;
	duk_idx_t i, n;
	duk_ucodepoint_t cp;

	/* XXX: It would be nice to build the string directly but ToUint16()
	 * coercion is needed so a generic helper would not be very
	 * helpful (perhaps coerce the value stack first here and then
	 * build a string from a duk_tval number sequence in one go?).
	 */

	n = duk_get_top(ctx);

	bw = &bw_alloc;
	DUK_BW_INIT_PUSHBUF(thr, bw, n);  /* initial estimate for ASCII only codepoints */

	for (i = 0; i < n; i++) {
		/* XXX: could improve bufwriter handling to write multiple codepoints
		 * with one ensure call but the relative benefit would be quite small.
		 */

		if (nonbmp) {
			/* ES6 requires that (1) SameValue(cp, ToInteger(cp)) and
			 * (2) cp >= 0 and cp <= 0x10ffff.  This check does not
			 * implement the steps exactly but the outcome should be
			 * the same.
			 */
			duk_int32_t i32 = 0;
			if (!duk_is_whole_get_int32(duk_to_number(ctx, i), &i32) ||
			    i32 < 0 || i32 > 0x10ffffL) {
				DUK_DCERROR_RANGE_INVALID_ARGS((duk_hthread *) ctx);
			}
			cp = (duk_ucodepoint_t) i32;
			DUK_ASSERT(cp >= 0 && cp <= 0x10ffffL);
			DUK_BW_WRITE_ENSURE_CESU8(thr, bw, cp);
		} else {
#if defined(DUK_USE_NONSTD_STRING_FROMCHARCODE_32BIT)
			/* ToUint16() coercion is mandatory in the E5.1 specification, but
			 * this non-compliant behavior makes more sense because we support
			 * non-BMP codepoints.  Don't use CESU-8 because that'd create
			 * surrogate pairs.
			 */
			cp = (duk_ucodepoint_t) duk_to_uint32(ctx, i);
			DUK_BW_WRITE_ENSURE_XUTF8(thr, bw, cp);
#else
			cp = (duk_ucodepoint_t) duk_to_uint16(ctx, i);
			DUK_ASSERT(cp >= 0 && cp <= 0x10ffffL);
			DUK_BW_WRITE_ENSURE_CESU8(thr, bw, cp);
#endif
		}
	}

	DUK_BW_COMPACT(thr, bw);
	(void) duk_buffer_to_string(ctx, -1);
	return 1;
}
Пример #2
0
DUK_INTERNAL duk_ret_t duk_bi_string_constructor_from_char_code(duk_context *ctx) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_bufwriter_ctx bw_alloc;
	duk_bufwriter_ctx *bw;
	duk_idx_t i, n;
	duk_ucodepoint_t cp;

	/* XXX: It would be nice to build the string directly but ToUint16()
	 * coercion is needed so a generic helper would not be very
	 * helpful (perhaps coerce the value stack first here and then
	 * build a string from a duk_tval number sequence in one go?).
	 */

	n = duk_get_top(ctx);

	bw = &bw_alloc;
	DUK_BW_INIT_PUSHBUF(thr, bw, n);  /* initial estimate for ASCII only codepoints */

	for (i = 0; i < n; i++) {
		/* XXX: could improve bufwriter handling to write multiple codepoints
		 * with one ensure call but the relative benefit would be quite small.
		 */

#if defined(DUK_USE_NONSTD_STRING_FROMCHARCODE_32BIT)
		/* ToUint16() coercion is mandatory in the E5.1 specification, but
		 * this non-compliant behavior makes more sense because we support
		 * non-BMP codepoints.  Don't use CESU-8 because that'd create
		 * surrogate pairs.
		 */

		cp = (duk_ucodepoint_t) duk_to_uint32(ctx, i);
		DUK_BW_WRITE_ENSURE_XUTF8(thr, bw, cp);
#else
		cp = (duk_ucodepoint_t) duk_to_uint32(ctx, i);
		DUK_BW_WRITE_ENSURE_CESU8(thr, bw, cp);
#endif
	}

	DUK_BW_COMPACT(thr, bw);
	duk_to_string(ctx, -1);
	return 1;
}