MIRROR: javascript for 🐜's, a tiny runtime with big ambitions
improve fast path
+13
-4
+13
-4
src/silver/ops/property.h
+13
-4
src/silver/ops/property.h
···
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ant_offset_t byte_len = 0;
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ant_offset_t str_off = vstr(js, str, &byte_len);
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const char *str_data = (const char *)(uintptr_t)(str_off);
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-
size_t char_bytes = 0;
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-
int byte_offset = utf16_index_to_byte_offset(str_data, byte_len, idx, &char_bytes);
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-
if (byte_offset < 0 || char_bytes == 0) {
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+
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+
uint32_t code_unit = utf16_code_unit_at(str_data, byte_len, idx);
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+
if (code_unit == 0xFFFFFFFF) {
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*out = js_mkundef();
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return true;
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}
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-
*out = js_mkstr(js, str_data + byte_offset, char_bytes);
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+
char buf[4];
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size_t out_len = 0;
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+
if (code_unit >= 0xD800 && code_unit <= 0xDFFF) {
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+
buf[0] = (char)(0xE0 | (code_unit >> 12));
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+
buf[1] = (char)(0x80 | ((code_unit >> 6) & 0x3F));
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buf[2] = (char)(0x80 | (code_unit & 0x3F));
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out_len = 3;
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+
} else out_len = (size_t)utf8_encode(code_unit, buf);
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+
*out = js_mkstr(js, buf, out_len);
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+
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return true;
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}
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