DUK_INTERNAL duk_ret_t duk_bi_string_prototype_slice(duk_context *ctx) {
duk_hstring *h;
duk_int_t start_pos, end_pos;
duk_int_t len;
h = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h != NULL);
len = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h);
/* [ start end str ] */
start_pos = duk_to_int_clamped(ctx, 0, -len, len);
if (start_pos < 0) {
start_pos = len + start_pos;
}
if (duk_is_undefined(ctx, 1)) {
end_pos = len;
} else {
end_pos = duk_to_int_clamped(ctx, 1, -len, len);
if (end_pos < 0) {
end_pos = len + end_pos;
}
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
DUK_ASSERT(end_pos >= 0 && end_pos <= len);
if (end_pos < start_pos) {
end_pos = start_pos;
}
DUK_ASSERT(end_pos >= start_pos);
duk_substring(ctx, -1, (duk_size_t) start_pos, (duk_size_t) end_pos);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_array_prototype_slice(duk_context *ctx) {
duk_uint32_t len;
duk_int_t start, end;
duk_int_t i;
duk_uarridx_t idx;
duk_uint32_t res_length = 0;
/* XXX: len >= 0x80000000 won't work below because we need to be
* able to represent -len.
*/
len = duk__push_this_obj_len_u32_limited(ctx);
duk_push_array(ctx);
/* stack[0] = start
* stack[1] = end
* stack[2] = ToObject(this)
* stack[3] = ToUint32(length)
* stack[4] = result array
*/
start = duk_to_int_clamped(ctx, 0, -((duk_int_t) len), (duk_int_t) len);
if (start < 0) {
start = len + start;
}
/* XXX: could duk_is_undefined() provide defaulting undefined to 'len'
* (the upper limit)?
*/
if (duk_is_undefined(ctx, 1)) {
end = len;
} else {
end = duk_to_int_clamped(ctx, 1, -((duk_int_t) len), (duk_int_t) len);
if (end < 0) {
end = len + end;
}
}
DUK_ASSERT(start >= 0 && (duk_uint32_t) start <= len);
DUK_ASSERT(end >= 0 && (duk_uint32_t) end <= len);
idx = 0;
for (i = start; i < end; i++) {
DUK_ASSERT_TOP(ctx, 5);
if (duk_get_prop_index(ctx, 2, (duk_uarridx_t) i)) {
duk_xdef_prop_index_wec(ctx, 4, idx);
res_length = idx + 1;
} else {
duk_pop(ctx);
}
idx++;
DUK_ASSERT_TOP(ctx, 5);
}
duk_push_u32(ctx, res_length);
duk_xdef_prop_stridx(ctx, 4, DUK_STRIDX_LENGTH, DUK_PROPDESC_FLAGS_W);
DUK_ASSERT_TOP(ctx, 5);
return 1;
}
int duk_bi_array_prototype_slice(duk_context *ctx) {
unsigned int len;
int start, end;
int idx;
int i;
duk_uint32_t res_length = 0;
len = duk__push_this_obj_len_u32(ctx);
duk_push_array(ctx);
/* stack[0] = start
* stack[1] = end
* stack[2] = ToObject(this)
* stack[3] = ToUint32(length)
* stack[4] = result array
*/
start = duk_to_int_clamped(ctx, 0, -len, len); /* FIXME: does not support full 32-bit range */
if (start < 0) {
start = len + start;
}
/* FIXME: could duk_is_undefined() provide defaulting undefined to 'len'
* (the upper limit)?
*/
if (duk_is_undefined(ctx, 1)) {
end = len;
} else {
end = duk_to_int_clamped(ctx, 1, -len, len);
if (end < 0) {
end = len + end;
}
}
DUK_ASSERT(start >= 0 && (duk_uint32_t) start <= len);
DUK_ASSERT(end >= 0 && (duk_uint32_t) end <= len);
idx = 0;
for (i = start; i < end; i++) {
DUK_ASSERT_TOP(ctx, 5);
if (duk_get_prop_index(ctx, 2, i)) {
duk_def_prop_index(ctx, 4, idx, DUK_PROPDESC_FLAGS_WEC);
res_length = idx + 1;
} else {
duk_pop(ctx);
}
idx++;
DUK_ASSERT_TOP(ctx, 5);
}
duk_push_int(ctx, res_length); /* FIXME */
duk_def_prop_stridx(ctx, 4, DUK_STRIDX_LENGTH, DUK_PROPDESC_FLAGS_W);
DUK_ASSERT_TOP(ctx, 5);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_substr(duk_context *ctx) {
duk_hstring *h;
duk_int_t start_pos, end_pos;
duk_int_t len;
/* Unlike non-obsolete String calls, substr() algorithm in E5.1
* specification will happily coerce undefined and null to strings
* ("undefined" and "null").
*/
duk_push_this(ctx);
h = duk_to_hstring(ctx, -1);
DUK_ASSERT(h != NULL);
len = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h);
/* [ start length str ] */
/* The implementation for computing of start_pos and end_pos differs
* from the standard algorithm, but is intended to result in the exactly
* same behavior. This is not always obvious.
*/
/* combines steps 2 and 5; -len ensures max() not needed for step 5 */
start_pos = duk_to_int_clamped(ctx, 0, -len, len);
if (start_pos < 0) {
start_pos = len + start_pos;
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
/* combines steps 3, 6; step 7 is not needed */
if (duk_is_undefined(ctx, 1)) {
end_pos = len;
} else {
DUK_ASSERT(start_pos <= len);
end_pos = start_pos + duk_to_int_clamped(ctx, 1, 0, len - start_pos);
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
DUK_ASSERT(end_pos >= 0 && end_pos <= len);
DUK_ASSERT(end_pos >= start_pos);
duk_substring(ctx, -1, (duk_size_t) start_pos, (duk_size_t) end_pos);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_indexof_shared(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_hstring *h_this;
duk_hstring *h_search;
duk_int_t clen_this;
duk_int_t cpos;
duk_int_t bpos;
const duk_uint8_t *p_start, *p_end, *p;
const duk_uint8_t *q_start;
duk_int_t q_blen;
duk_uint8_t firstbyte;
duk_uint8_t t;
duk_small_int_t is_lastindexof = duk_get_current_magic(ctx); /* 0=indexOf, 1=lastIndexOf */
h_this = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h_this != NULL);
clen_this = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h_this);
h_search = duk_to_hstring(ctx, 0);
DUK_ASSERT(h_search != NULL);
q_start = DUK_HSTRING_GET_DATA(h_search);
q_blen = (duk_int_t) DUK_HSTRING_GET_BYTELEN(h_search);
duk_to_number(ctx, 1);
if (duk_is_nan(ctx, 1) && is_lastindexof) {
/* indexOf: NaN should cause pos to be zero.
* lastIndexOf: NaN should cause pos to be +Infinity
* (and later be clamped to len).
*/
cpos = clen_this;
} else {
cpos = duk_to_int_clamped(ctx, 1, 0, clen_this);
}
/* Empty searchstring always matches; cpos must be clamped here.
* (If q_blen were < 0 due to clamped coercion, it would also be
* caught here.)
*/
if (q_blen <= 0) {
duk_push_int(ctx, cpos);
return 1;
}
DUK_ASSERT(q_blen > 0);
bpos = (duk_int_t) duk_heap_strcache_offset_char2byte(thr, h_this, (duk_uint32_t) cpos);
p_start = DUK_HSTRING_GET_DATA(h_this);
p_end = p_start + DUK_HSTRING_GET_BYTELEN(h_this);
p = p_start + bpos;
/* This loop is optimized for size. For speed, there should be
* two separate loops, and we should ensure that memcmp() can be
* used without an extra "will searchstring fit" check. Doing
* the preconditioning for 'p' and 'p_end' is easy but cpos
* must be updated if 'p' is wound back (backward scanning).
*/
firstbyte = q_start[0]; /* leading byte of match string */
while (p <= p_end && p >= p_start) {
t = *p;
/* For Ecmascript strings, this check can only match for
* initial UTF-8 bytes (not continuation bytes). For other
* strings all bets are off.
*/
if ((t == firstbyte) && ((duk_size_t) (p_end - p) >= (duk_size_t) q_blen)) {
DUK_ASSERT(q_blen > 0); /* no issues with memcmp() zero size, even if broken */
if (DUK_MEMCMP(p, q_start, (duk_size_t) q_blen) == 0) {
duk_push_int(ctx, cpos);
return 1;
}
}
/* track cpos while scanning */
if (is_lastindexof) {
/* when going backwards, we decrement cpos 'early';
* 'p' may point to a continuation byte of the char
* at offset 'cpos', but that's OK because we'll
* backtrack all the way to the initial byte.
*/
if ((t & 0xc0) != 0x80) {
cpos--;
}
p--;
} else {
if ((t & 0xc0) != 0x80) {
cpos++;
}
p++;
}
}
/* Not found. Empty string case is handled specially above. */
duk_push_int(ctx, -1);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_array_prototype_splice(duk_context *ctx) {
duk_idx_t nargs;
duk_uint32_t len;
duk_bool_t have_delcount;
duk_int_t item_count;
duk_int_t act_start;
duk_int_t del_count;
duk_int_t i, n;
DUK_UNREF(have_delcount);
nargs = duk_get_top(ctx);
if (nargs < 2) {
duk_set_top(ctx, 2);
nargs = 2;
have_delcount = 0;
} else {
have_delcount = 1;
}
/* XXX: len >= 0x80000000 won't work below because we need to be
* able to represent -len.
*/
len = duk__push_this_obj_len_u32_limited(ctx);
act_start = duk_to_int_clamped(ctx, 0, -((duk_int_t) len), (duk_int_t) len);
if (act_start < 0) {
act_start = len + act_start;
}
DUK_ASSERT(act_start >= 0 && act_start <= (duk_int_t) len);
#ifdef DUK_USE_NONSTD_ARRAY_SPLICE_DELCOUNT
if (have_delcount) {
#endif
del_count = duk_to_int_clamped(ctx, 1, 0, len - act_start);
#ifdef DUK_USE_NONSTD_ARRAY_SPLICE_DELCOUNT
} else {
/* E5.1 standard behavior when deleteCount is not given would be
* to treat it just like if 'undefined' was given, which coerces
* ultimately to 0. Real world behavior is to splice to the end
* of array, see test-bi-array-proto-splice-no-delcount.js.
*/
del_count = len - act_start;
}
#endif
DUK_ASSERT(nargs >= 2);
item_count = (duk_int_t) (nargs - 2);
DUK_ASSERT(del_count >= 0 && del_count <= (duk_int_t) len - act_start);
DUK_ASSERT(del_count + act_start <= (duk_int_t) len);
/* For now, restrict result array into 32-bit length range. */
if (((duk_double_t) len) - ((duk_double_t) del_count) + ((duk_double_t) item_count) > (duk_double_t) DUK_UINT32_MAX) {
DUK_D(DUK_DPRINT("Array.prototype.splice() would go beyond 32-bit length, throw"));
return DUK_RET_RANGE_ERROR;
}
duk_push_array(ctx);
/* stack[0] = start
* stack[1] = deleteCount
* stack[2...nargs-1] = items
* stack[nargs] = ToObject(this) -3
* stack[nargs+1] = ToUint32(length) -2
* stack[nargs+2] = result array -1
*/
DUK_ASSERT_TOP(ctx, nargs + 3);
/* Step 9: copy elements-to-be-deleted into the result array */
for (i = 0; i < del_count; i++) {
if (duk_get_prop_index(ctx, -3, (duk_uarridx_t) (act_start + i))) {
duk_xdef_prop_index_wec(ctx, -2, i); /* throw flag irrelevant (false in std alg) */
} else {
duk_pop(ctx);
}
}
duk_push_u32(ctx, (duk_uint32_t) del_count);
duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_LENGTH, DUK_PROPDESC_FLAGS_W);
/* Steps 12 and 13: reorganize elements to make room for itemCount elements */
if (item_count < del_count) {
/* [ A B C D E F G H ] rel_index = 2, del_count 3, item count 1
* -> [ A B F G H ] (conceptual intermediate step)
* -> [ A B . F G H ] (placeholder marked)
* [ A B C F G H ] (actual result at this point, C will be replaced)
*/
DUK_ASSERT_TOP(ctx, nargs + 3);
n = len - del_count;
for (i = act_start; i < n; i++) {
if (duk_get_prop_index(ctx, -3, (duk_uarridx_t) (i + del_count))) {
duk_put_prop_index(ctx, -4, (duk_uarridx_t) (i + item_count));
} else {
duk_pop(ctx);
duk_del_prop_index(ctx, -3, (duk_uarridx_t) (i + item_count));
}
}
DUK_ASSERT_TOP(ctx, nargs + 3);
/* loop iterator init and limit changed from standard algorithm */
n = len - del_count + item_count;
for (i = len - 1; i >= n; i--) {
duk_del_prop_index(ctx, -3, (duk_uarridx_t) i);
}
DUK_ASSERT_TOP(ctx, nargs + 3);
} else if (item_count > del_count) {
/* [ A B C D E F G H ] rel_index = 2, del_count 3, item count 4
* -> [ A B F G H ] (conceptual intermediate step)
* -> [ A B . . . . F G H ] (placeholder marked)
* [ A B C D E F F G H ] (actual result at this point)
*/
DUK_ASSERT_TOP(ctx, nargs + 3);
/* loop iterator init and limit changed from standard algorithm */
for (i = len - del_count - 1; i >= act_start; i--) {
if (duk_get_prop_index(ctx, -3, (duk_uarridx_t) (i + del_count))) {
duk_put_prop_index(ctx, -4, (duk_uarridx_t) (i + item_count));
} else {
duk_pop(ctx);
duk_del_prop_index(ctx, -3, (duk_uarridx_t) (i + item_count));
}
}
DUK_ASSERT_TOP(ctx, nargs + 3);
} else {
/* [ A B C D E F G H ] rel_index = 2, del_count 3, item count 3
* -> [ A B F G H ] (conceptual intermediate step)
* -> [ A B . . . F G H ] (placeholder marked)
* [ A B C D E F G H ] (actual result at this point)
*/
}
DUK_ASSERT_TOP(ctx, nargs + 3);
/* Step 15: insert itemCount elements into the hole made above */
for (i = 0; i < item_count; i++) {
duk_dup(ctx, i + 2); /* args start at index 2 */
duk_put_prop_index(ctx, -4, (duk_uarridx_t) (act_start + i));
}
/* Step 16: update length; note that the final length may be above 32 bit range
* (but we checked above that this isn't the case here)
*/
duk_push_u32(ctx, len - del_count + item_count);
duk_put_prop_stridx(ctx, -4, DUK_STRIDX_LENGTH);
/* result array is already at the top of stack */
DUK_ASSERT_TOP(ctx, nargs + 3);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_array_prototype_indexof_shared(duk_context *ctx) {
duk_idx_t nargs;
duk_int_t i, len;
duk_int_t from_index;
duk_small_int_t idx_step = duk_get_current_magic(ctx); /* idx_step is +1 for indexOf, -1 for lastIndexOf */
/* lastIndexOf() needs to be a vararg function because we must distinguish
* between an undefined fromIndex and a "not given" fromIndex; indexOf() is
* made vararg for symmetry although it doesn't strictly need to be.
*/
nargs = duk_get_top(ctx);
duk_set_top(ctx, 2);
/* XXX: must be able to represent -len */
len = (duk_int_t) duk__push_this_obj_len_u32_limited(ctx);
if (len == 0) {
goto not_found;
}
/* Index clamping is a bit tricky, we must ensure that we'll only iterate
* through elements that exist and that the specific requirements from E5.1
* Sections 15.4.4.14 and 15.4.4.15 are fulfilled; especially:
*
* - indexOf: clamp to [-len,len], negative handling -> [0,len],
* if clamped result is len, for-loop bails out immediately
*
* - lastIndexOf: clamp to [-len-1, len-1], negative handling -> [-1, len-1],
* if clamped result is -1, for-loop bails out immediately
*
* If fromIndex is not given, ToInteger(undefined) = 0, which is correct
* for indexOf() but incorrect for lastIndexOf(). Hence special handling,
* and why lastIndexOf() needs to be a vararg function.
*/
if (nargs >= 2) {
/* indexOf: clamp fromIndex to [-len, len]
* (if fromIndex == len, for-loop terminates directly)
*
* lastIndexOf: clamp fromIndex to [-len - 1, len - 1]
* (if clamped to -len-1 -> fromIndex becomes -1, terminates for-loop directly)
*/
from_index = duk_to_int_clamped(ctx,
1,
(idx_step > 0 ? -len : -len - 1),
(idx_step > 0 ? len : len - 1));
if (from_index < 0) {
/* for lastIndexOf, result may be -1 (mark immediate termination) */
from_index = len + from_index;
}
} else {
/* for indexOf, ToInteger(undefined) would be 0, i.e. correct, but
* handle both indexOf and lastIndexOf specially here.
*/
if (idx_step > 0) {
from_index = 0;
} else {
from_index = len - 1;
}
}
/* stack[0] = searchElement
* stack[1] = fromIndex
* stack[2] = object
* stack[3] = length (not needed, but not popped above)
*/
for (i = from_index; i >= 0 && i < len; i += idx_step) {
DUK_ASSERT_TOP(ctx, 4);
if (duk_get_prop_index(ctx, 2, (duk_uarridx_t) i)) {
DUK_ASSERT_TOP(ctx, 5);
if (duk_strict_equals(ctx, 0, 4)) {
duk_push_int(ctx, i);
return 1;
}
}
duk_pop(ctx);
}
not_found:
duk_push_int(ctx, -1);
return 1;
}
int duk_bi_array_prototype_splice(duk_context *ctx) {
int nargs;
int have_delcount;
int item_count;
int len;
int act_start;
int del_count;
int i;
DUK_UNREF(have_delcount);
nargs = duk_get_top(ctx);
if (nargs < 2) {
duk_set_top(ctx, 2);
nargs = 2;
have_delcount = 0;
} else {
have_delcount = 1;
}
len = duk__push_this_obj_len_u32(ctx);
act_start = duk_to_int_clamped(ctx, 0, -len, len);
if (act_start < 0) {
act_start = len + act_start;
}
DUK_ASSERT(act_start >= 0 && act_start <= len);
#ifdef DUK_USE_NONSTD_ARRAY_SPLICE_DELCOUNT
if (have_delcount) {
#endif
del_count = duk_to_int_clamped(ctx, 1, 0, len - act_start);
#ifdef DUK_USE_NONSTD_ARRAY_SPLICE_DELCOUNT
} else {
/* E5.1 standard behavior when deleteCount is not given would be
* to treat it just like if 'undefined' was given, which coerces
* ultimately to 0. Real world behavior is to splice to the end
* of array, see test-bi-array-proto-splice-no-delcount.js.
*/
del_count = len - act_start;
}
#endif
DUK_ASSERT(del_count >= 0 && del_count <= len - act_start);
DUK_ASSERT(del_count + act_start <= len);
duk_push_array(ctx);
/* stack[0] = start
* stack[1] = deleteCount
* stack[2...nargs-1] = items
* stack[nargs] = ToObject(this) -3
* stack[nargs+1] = ToUint32(length) -2
* stack[nargs+2] = result array -1
*/
DUK_ASSERT_TOP(ctx, nargs + 3);
/* Step 9: copy elements-to-be-deleted into the result array */
for (i = 0; i < del_count; i++) {
if (duk_get_prop_index(ctx, -3, act_start + i)) {
duk_def_prop_index(ctx, -2, i, DUK_PROPDESC_FLAGS_WEC); /* throw flag irrelevant (false in std alg) */
} else {
duk_pop(ctx);
}
}
duk_push_int(ctx, del_count); /* FIXME: typing */
duk_def_prop_stridx(ctx, -2, DUK_STRIDX_LENGTH, DUK_PROPDESC_FLAGS_W);
/* Steps 12 and 13: reorganize elements to make room for itemCount elements */
DUK_ASSERT(nargs >= 2);
item_count = nargs - 2;
if (item_count < del_count) {
/* [ A B C D E F G H ] rel_index = 2, del_count 3, item count 1
* -> [ A B F G H ] (conceptual intermediate step)
* -> [ A B . F G H ] (placeholder marked)
* [ A B C F G H ] (actual result at this point, C will be replaced)
*/
DUK_ASSERT_TOP(ctx, nargs + 3);
for (i = act_start; i < len - del_count; i++) {
if (duk_get_prop_index(ctx, -3, i + del_count)) {
duk_put_prop_index(ctx, -4, i + item_count); /* FIXME: Throw */
} else {
duk_pop(ctx);
duk_del_prop_index(ctx, -3, i + item_count); /* FIXME: Throw */
}
}
DUK_ASSERT_TOP(ctx, nargs + 3);
/* loop iterator init and limit changed from standard algorithm */
for (i = len - 1; i >= len - del_count + item_count; i--) {
duk_del_prop_index(ctx, -3, i); /* FIXME: Throw */
}
DUK_ASSERT_TOP(ctx, nargs + 3);
} else if (item_count > del_count) {
/* [ A B C D E F G H ] rel_index = 2, del_count 3, item count 4
* -> [ A B F G H ] (conceptual intermediate step)
* -> [ A B . . . . F G H ] (placeholder marked)
* [ A B C D E F F G H ] (actual result at this point)
*/
DUK_ASSERT_TOP(ctx, nargs + 3);
/* loop iterator init and limit changed from standard algorithm */
for (i = len - del_count - 1; i >= act_start; i--) {
if (duk_get_prop_index(ctx, -3, i + del_count)) {
duk_put_prop_index(ctx, -4, i + item_count); /* FIXME: Throw */
} else {
duk_pop(ctx);
duk_del_prop_index(ctx, -3, i + item_count); /* FIXME: Throw */
}
}
DUK_ASSERT_TOP(ctx, nargs + 3);
} else {
/* [ A B C D E F G H ] rel_index = 2, del_count 3, item count 3
* -> [ A B F G H ] (conceptual intermediate step)
* -> [ A B . . . F G H ] (placeholder marked)
* [ A B C D E F G H ] (actual result at this point)
*/
}
DUK_ASSERT_TOP(ctx, nargs + 3);
/* Step 15: insert itemCount elements into the hole made above */
for (i = 0; i < item_count; i++) {
duk_dup(ctx, i + 2); /* args start at index 2 */
duk_put_prop_index(ctx, -4, act_start + i); /* FIXME: Throw */
}
/* Step 16: update length; note that the final length may be above 32 bit range */
duk_push_number(ctx, ((double) len) - ((double) del_count) + ((double) item_count));
duk_put_prop_stridx(ctx, -4, DUK_STRIDX_LENGTH);
/* result array is already at the top of stack */
DUK_ASSERT_TOP(ctx, nargs + 3);
return 1;
}
