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;
}
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;
}