-
-
Notifications
You must be signed in to change notification settings - Fork 114
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
feat(stdlib): Number.parseInt (#1051)
- Loading branch information
Showing
3 changed files
with
234 additions
and
6 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,172 @@ | ||
| // TODO(#1050): Remove dependency on Pervasives once Option/Result types are imbedded in the compiler | ||
|
|
||
| import WasmI32, { | ||
| add as (+), | ||
| sub as (-), | ||
| gtU as (>), | ||
| geU as (>=), | ||
| ltU as (<), | ||
| shrS as (>>), | ||
| eq as (==), | ||
| ne as (!=), | ||
| and as (&), | ||
| } from "runtime/unsafe/wasmi32" | ||
| import WasmI64 from "runtime/unsafe/wasmi64" | ||
| import Memory from "runtime/unsafe/memory" | ||
| import Tags from "runtime/unsafe/tags" | ||
| import { reducedInteger } from "runtime/numbers" | ||
|
|
||
| @disableGC | ||
| export let rec parseInt = (string: String, radix: Number) => { | ||
| let _CHAR_0 = 0x30n | ||
| let _CHAR_B = 0x42n | ||
| let _CHAR_b = 0x62n | ||
| let _CHAR_O = 0x4fn | ||
| let _CHAR_o = 0x6fn | ||
| let _CHAR_X = 0x58n | ||
| let _CHAR_x = 0x78n | ||
|
|
||
| let _CHAR_A = 0x41n | ||
| let _CHAR_a = 0x61n | ||
|
|
||
| let _CHAR_UNDERSCORE = 0x5fn | ||
| let _CHAR_MINUS = 0x2dn | ||
|
|
||
| let _INT_MIN = -9223372036854775808N | ||
|
|
||
| // Don't need to process Unicode length since if the string | ||
| // contains non-ascii characters, it's not a valid integer | ||
| let strLen = WasmI32.load(WasmI32.fromGrain(string), 4n) | ||
|
|
||
| // Our pointer within the string we're parsing, offset by the | ||
| // header | ||
| let mut offset = WasmI32.fromGrain(string) + 8n | ||
|
|
||
| let strEnd = offset + strLen | ||
|
|
||
| let radix = WasmI32.fromGrain(radix) | ||
| let result = if (WasmI32.eqz(radix & Tags._GRAIN_NUMBER_TAG_MASK) || radix < WasmI32.fromGrain(2) || radix > WasmI32.fromGrain(36)) { | ||
| Memory.incRef(WasmI32.fromGrain(Err)) | ||
| Err("Radix must be an integer between 2 and 36") | ||
| } else if (WasmI32.eqz(strLen)) { | ||
| Memory.incRef(WasmI32.fromGrain(Err)) | ||
| Err("Invalid input") | ||
| } else { | ||
| let mut char = WasmI32.load8U(offset, 0n) | ||
|
|
||
| let mut limit = WasmI64.add(_INT_MIN, 1N) | ||
|
|
||
| // Check for a sign | ||
| let mut negative = false | ||
| if (char == _CHAR_MINUS) { | ||
| negative = true | ||
| offset += 1n | ||
| limit = _INT_MIN | ||
| char = WasmI32.load8U(offset, 0n) | ||
| } | ||
|
|
||
| let mut radix = WasmI64.extendI32S(radix >> 1n) | ||
|
|
||
| // Check if we should override the supplied radix | ||
| if (char == _CHAR_0 && strLen > 2n) { | ||
| match (WasmI32.load8U(offset, 1n)) { | ||
| c when c == _CHAR_B || c == _CHAR_b => { | ||
| radix = 2N | ||
| offset += 2n | ||
| }, | ||
| c when c == _CHAR_O || c == _CHAR_o => { | ||
| radix = 8N | ||
| offset += 2n | ||
| }, | ||
| c when c == _CHAR_X || c == _CHAR_x => { | ||
| radix = 16N | ||
| offset += 2n | ||
| }, | ||
| _ => void, | ||
| } | ||
| } | ||
|
|
||
| let mut value = 0N | ||
|
|
||
| // we use 0 to represent no error, 1 to represent an invalid | ||
| // input, and 2 to represent an overflow | ||
| let mut error = 1n | ||
|
|
||
| for (let mut i = offset; i < strEnd; i += 1n) { | ||
| let char = WasmI32.load8U(i, 0n) | ||
|
|
||
| // Ignore underscore characters | ||
| if (char == _CHAR_UNDERSCORE) { | ||
| continue | ||
| } | ||
|
|
||
| // We've seen at least one non-underscore character, so we'll consider | ||
| // the input valid until we find out otherwise | ||
|
|
||
| error = 0n | ||
|
|
||
| let mut digit = 0n | ||
|
|
||
| match (char) { | ||
| c when c - _CHAR_0 < 10n => digit = char - _CHAR_0, | ||
| c when c - _CHAR_A < 26n => digit = char - _CHAR_A + 10n, | ||
| c when c - _CHAR_a < 26n => digit = char - _CHAR_a + 10n, | ||
| _ => { | ||
| error = 1n | ||
| // invalid digit | ||
| break | ||
| }, | ||
| } | ||
|
|
||
| if (digit >= WasmI32.wrapI64(radix)) { | ||
| error = 1n | ||
| // invalid digit | ||
| break | ||
| } | ||
|
|
||
| let digit = WasmI64.extendI32U(digit) | ||
|
|
||
| value = WasmI64.mul(value, radix) | ||
|
|
||
| // Check for overflow | ||
| // 64-bit int min + 1 | ||
| if (WasmI64.ltS(value, WasmI64.add(limit, digit))) { | ||
| error = 2n | ||
| // overflow | ||
| break | ||
| } | ||
|
|
||
| // To quote the OpenJDK, | ||
| // "Accumulating negatively avoids surprises near MAX_VALUE" | ||
| // The minimum value of a 64-bit integer (-9223372036854775808) can't be | ||
| // represented as a positive number because it would be larger than the | ||
| // maximum 64-bit integer (9223372036854775807), so we'd be unable to | ||
| // parse negatives as positives and multiply by the sign at the end. | ||
| // Instead, we represent all positive numbers as negative numbers since | ||
| // we have one unit more headroom. | ||
| value = WasmI64.sub(value, digit) | ||
| } | ||
|
|
||
| match (error) { | ||
| 1n => { | ||
| Memory.incRef(WasmI32.fromGrain(Err)) | ||
| Err("Invalid digit in input") | ||
| }, | ||
| 2n => { | ||
| Memory.incRef(WasmI32.fromGrain(Err)) | ||
| Err("Input out of range of representable integers") | ||
| }, | ||
| _ => { | ||
| let value = if (negative) value else WasmI64.mul(value, -1N) | ||
| let number = WasmI32.toGrain(reducedInteger(value)): (Number) | ||
| Memory.incRef(WasmI32.fromGrain(Ok)) | ||
| Ok(number) | ||
| }, | ||
| } | ||
| } | ||
|
|
||
| Memory.decRef(WasmI32.fromGrain(parseInt)) | ||
| Memory.decRef(radix) | ||
|
|
||
| result | ||
| } |