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Add String.fromUTF8 helper (see #291); Update dist files

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dcodeIO
2018-10-03 00:49:56 +02:00
parent 53b030fed5
commit b7e7be20cf
9 changed files with 5344 additions and 15 deletions
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1
std/assembly/index.d.ts vendored
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@ -490,6 +490,7 @@ declare class String {
padEnd(targetLength: i32, padString?: string): string;
repeat(count?: i32): string;
toString(): string;
static fromUTF8(ptr: usize, len: usize): string;
toUTF8(): usize;
}

43
std/assembly/string.ts
View File

@ -436,6 +436,49 @@ export class String {
return len;
}
static fromUTF8(ptr: usize, len: usize): String {
if (len < 1) return changetype<String>("");
var ptrPos = <usize>0;
var buf = memory.allocate(<usize>len << 1);
var bufPos = <usize>0;
while (ptrPos < len) {
let cp = <u32>load<u8>(ptr + ptrPos++);
if (cp < 128) {
store<u16>(buf + bufPos, cp);
bufPos += 2;
} else if (cp > 191 && cp < 224) {
assert(ptrPos + 1 <= len);
store<u16>(buf + bufPos, (cp & 31) << 6 | load<u8>(ptr + ptrPos++) & 63);
bufPos += 2;
} else if (cp > 239 && cp < 365) {
assert(ptrPos + 3 <= len);
cp = (
(cp & 7) << 18 |
(load<u8>(ptr + ptrPos++) & 63) << 12 |
(load<u8>(ptr + ptrPos++) & 63) << 6 |
load<u8>(ptr + ptrPos++) & 63
) - 0x10000;
store<u16>(buf + bufPos, 0xD800 + (cp >> 10));
bufPos += 2;
store<u16>(buf + bufPos, 0xDC00 + (cp & 1023));
bufPos += 2;
} else {
assert(ptrPos + 2 <= len);
store<u16>(buf + bufPos,
(cp & 15) << 12 |
(load<u8>(ptr + ptrPos++) & 63) << 6 |
load<u8>(ptr + ptrPos++) & 63
);
bufPos += 2;
}
}
assert(ptrPos == len);
var str = allocateUnsafe(<u32>(bufPos >> 1));
memory.copy(changetype<usize>(str) + HEADER_SIZE, buf, bufPos);
memory.free(buf);
return str;
}
toUTF8(): usize {
var buf = memory.allocate(<usize>this.lengthUTF8);
var pos: usize = 0;