Implement String#padStart/padEnd; Refactor internal string copy, compare and repeat (#171)

This commit is contained in:
Max Graey
2018-07-25 17:25:53 +03:00
committed by Daniel Wirtz
parent 298a8f1688
commit 671121bf70
15 changed files with 6385 additions and 3983 deletions

View File

@ -489,6 +489,8 @@ declare class String {
trim(): string;
trimLeft(): string;
trimRight(): string;
padStart(targetLength: i32, padString?: string): string;
padEnd(targetLength: i32, padString?: string): string;
repeat(count?: i32): string;
toString(): string;
toUTF8(): usize;

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@ -17,7 +17,7 @@ export const EMPTY = changetype<String>(""); // TODO: is this a bad idea with '=
@inline
export function clamp<T>(val: T, lo: T, hi: T): T {
return max<T>(min<T>(val, hi), lo);
return min<T>(max<T>(val, lo), hi);
}
/** Allocates a raw String with uninitialized contents. */
@ -28,6 +28,15 @@ export function allocate(length: i32): String {
return changetype<String>(buffer);
}
@inline
export function copyUnsafe(dest: String, destOffset: usize, src: String, srcOffset: usize, len: usize): void {
memory.copy(
changetype<usize>(dest) + (destOffset << 1) + HEADER_SIZE,
changetype<usize>(src) + (srcOffset << 1) + HEADER_SIZE,
len << 1
);
}
export function isWhiteSpaceOrLineTerminator(c: u16): bool {
switch (c) {
case 10: // <LF>
@ -76,24 +85,19 @@ export const enum CharCode {
export function parse<T>(str: String, radix: i32 = 0): T {
var len: i32 = str.length;
if (!len) {
return <T>NaN;
}
if (!len) return <T>NaN;
var ptr = changetype<usize>(str) /* + HEAD -> offset */;
var code = <i32>load<u16>(ptr, HEADER_SIZE);
// determine sign
var sign: T;
if (code == CharCode.MINUS) {
if (!--len) {
return <T>NaN;
}
if (!--len) return <T>NaN;
code = <i32>load<u16>(ptr += 2, HEADER_SIZE);
sign = -1;
} else if (code == CharCode.PLUS) {
if (!--len) {
return <T>NaN;
}
if (!--len) return <T>NaN;
code = <i32>load<u16>(ptr += 2, HEADER_SIZE);
sign = 1;
} else {
@ -122,9 +126,7 @@ export function parse<T>(str: String, radix: i32 = 0): T {
radix = 16;
break;
}
default: {
radix = 10;
}
default: radix = 10;
}
} else radix = 10;
} else if (radix < 2 || radix > 36) {
@ -141,22 +143,79 @@ export function parse<T>(str: String, radix: i32 = 0): T {
code -= CharCode.A - 10;
} else if (code >= CharCode.a && code <= CharCode.z) {
code -= CharCode.a - 10;
} else {
break;
}
if (code >= radix) {
break;
}
} else break;
if (code >= radix) break;
num = (num * radix) + code;
ptr += 2;
}
return sign * num;
}
export function compareUTF16(ptr1: usize, ptr2: usize, len: usize): i32 {
export function compareUnsafe(str1: String, offset1: usize, str2: String, offset2: usize, len: usize): i32 {
var cmp: i32 = 0;
var ptr1 = changetype<usize>(str1) + (offset1 << 1);
var ptr2 = changetype<usize>(str2) + (offset2 << 1);
while (len && !(cmp = <i32>load<u16>(ptr1, HEADER_SIZE) - <i32>load<u16>(ptr2, HEADER_SIZE))) {
--len, ++ptr1, ++ptr2;
}
return cmp;
}
export function repeatUnsafe(dest: String, destOffset: usize, src: String, count: i32): void {
var length = src.length;
if (ASC_SHRINK_LEVEL > 1) {
let strLen = length << 1;
let to = changetype<usize>(dest) + HEADER_SIZE + (destOffset << 1);
let from = changetype<usize>(src) + HEADER_SIZE;
for (let i = 0, len = strLen * count; i < len; i += strLen) {
memory.copy(to + i, from, strLen);
}
} else {
switch (length) {
case 0: break;
case 1: {
let cc = load<u16>(changetype<usize>(src), HEADER_SIZE);
let out = changetype<usize>(dest) + (destOffset << 1);
for (let i = 0; i < count; ++i) {
store<u16>(out + (i << 1), cc, HEADER_SIZE);
}
break;
}
case 2: {
let cc = load<u32>(changetype<usize>(src), HEADER_SIZE);
let out = changetype<usize>(dest) + (destOffset << 1);
for (let i = 0; i < count; ++i) {
store<u32>(out + (i << 2), cc, HEADER_SIZE);
}
break;
}
case 3: {
let cc1 = load<u32>(changetype<usize>(src), HEADER_SIZE + 0);
let cc2 = load<u16>(changetype<usize>(src), HEADER_SIZE + 4);
let out = changetype<usize>(dest) + (destOffset << 1);
for (let i = 0; i < count; ++i) {
store<u32>(out + (i << 2), cc1, HEADER_SIZE + 0);
store<u16>(out + (i << 1), cc2, HEADER_SIZE + 4);
}
break;
}
case 4: {
let cc = load<u64>(changetype<usize>(src), HEADER_SIZE);
let out = changetype<usize>(dest) + (destOffset << 1);
for (let i = 0; i < count; ++i) {
store<u64>(out + (i << 3), cc, HEADER_SIZE);
}
break;
}
default: {
let strLen = length << 1;
let to = changetype<usize>(dest) + HEADER_SIZE + (destOffset << 1);
let from = changetype<usize>(src) + HEADER_SIZE;
for (let i = 0, len = strLen * count; i < len; i += strLen) {
memory.copy(to + i, from, strLen);
}
break;
}
}
}
}

View File

@ -4,7 +4,9 @@ import {
EMPTY,
clamp,
allocate,
compareUTF16,
compareUnsafe,
repeatUnsafe,
copyUnsafe,
isWhiteSpaceOrLineTerminator,
CharCode,
parse
@ -73,9 +75,8 @@ export class String {
charCodeAt(pos: i32): i32 {
assert(this !== null);
if (<u32>pos >= <u32>this.length) {
return -1; // (NaN)
}
if (<u32>pos >= <u32>this.length) return -1; // (NaN)
return load<u16>(
changetype<usize>(this) + (<usize>pos << 1),
HEADER_SIZE
@ -84,9 +85,8 @@ export class String {
codePointAt(pos: i32): i32 {
assert(this !== null);
if (<u32>pos >= <u32>this.length) {
return -1; // (undefined)
}
if (<u32>pos >= <u32>this.length) return -1; // (undefined)
var first = <i32>load<u16>(
changetype<usize>(this) + (<usize>pos << 1),
HEADER_SIZE
@ -111,24 +111,14 @@ export class String {
concat(other: String): String {
assert(this !== null);
if (other === null) other = changetype<String>("null");
var thisLen: isize = this.length;
var otherLen: isize = other.length;
var outLen: usize = thisLen + otherLen;
if (outLen == 0) return EMPTY;
var out = allocate(outLen);
memory.copy(
changetype<usize>(out) + HEADER_SIZE,
changetype<usize>(this) + HEADER_SIZE,
thisLen << 1
);
memory.copy(
changetype<usize>(out) + HEADER_SIZE + (thisLen << 1),
changetype<usize>(other) + HEADER_SIZE,
otherLen << 1
);
copyUnsafe(out, 0, this, 0, thisLen);
copyUnsafe(out, thisLen, other, 0, otherLen);
return out;
}
@ -139,11 +129,7 @@ export class String {
var searchLength: isize = searchString.length;
var start: isize = end - searchLength;
if (start < 0) return false;
return !compareUTF16(
changetype<usize>(this) + (start << 1),
changetype<usize>(searchString),
searchLength
);
return !compareUnsafe(this, start, searchString, 0, searchLength);
}
@operator("==")
@ -154,11 +140,7 @@ export class String {
var leftLength = left.length;
if (leftLength != right.length) return false;
return !compareUTF16(
changetype<usize>(left),
changetype<usize>(right),
leftLength
);
return !compareUnsafe(left, 0, right, 0, leftLength);
}
@operator("!=")
@ -177,11 +159,7 @@ export class String {
if (!rightLength) return true;
var length = <usize>min<i32>(leftLength, rightLength);
return compareUTF16(
changetype<usize>(left),
changetype<usize>(right),
length
) > 0;
return compareUnsafe(left, 0, right, 0, length) > 0;
}
@operator(">=")
@ -196,11 +174,7 @@ export class String {
if (!rightLength) return true;
var length = <usize>min<i32>(leftLength, rightLength);
return compareUTF16(
changetype<usize>(left),
changetype<usize>(right),
length
) >= 0;
return compareUnsafe(left, 0, right, 0, length) >= 0;
}
@operator("<")
@ -214,11 +188,7 @@ export class String {
if (!leftLength) return true;
var length = <usize>min<i32>(leftLength, rightLength);
return compareUTF16(
changetype<usize>(left),
changetype<usize>(right),
length
) < 0;
return compareUnsafe(left, 0, right, 0, length) < 0;
}
@operator("<=")
@ -233,11 +203,7 @@ export class String {
if (!leftLength) return true;
var length = <usize>min<i32>(leftLength, rightLength);
return compareUTF16(
changetype<usize>(left),
changetype<usize>(right),
length
) <= 0;
return compareUnsafe(left, 0, right, 0, length) <= 0;
}
includes(searchString: String, position: i32 = 0): bool {
@ -247,6 +213,7 @@ export class String {
indexOf(searchString: String, fromIndex: i32 = 0): i32 {
assert(this !== null);
if (searchString === null) searchString = changetype<String>("null");
var searchLen: isize = searchString.length;
if (!searchLen) return 0;
var len: isize = this.length;
@ -254,13 +221,7 @@ export class String {
var start = clamp<isize>(fromIndex, 0, len);
len -= searchLen;
for (let k: isize = start; k <= len; ++k) {
if (!compareUTF16(
changetype<usize>(this) + (k << 1),
changetype<usize>(searchString),
searchLen
)) {
return <i32>k;
}
if (!compareUnsafe(this, k, searchString, 0, searchLen)) return <i32>k;
}
return -1;
}
@ -268,21 +229,14 @@ export class String {
lastIndexOf(searchString: String, fromIndex: i32 = i32.MAX_VALUE): i32 {
assert(this !== null);
if (searchString === null) searchString = changetype<String>("null");
var len: isize = this.length;
var searchLen: isize = searchString.length;
if (!searchLen) return len;
if (!len) return -1;
var start = clamp<isize>(fromIndex, 0, len - searchLen);
// TODO: multiple char codes
for (let k = start; k >= 0; --k) {
if (!compareUTF16(
changetype<usize>(this) + (k << 1),
changetype<usize>(searchString),
searchLen
)) {
return <i32>k;
}
if (!compareUnsafe(this, k, searchString, 0, searchLen)) return <i32>k;
}
return -1;
}
@ -296,12 +250,7 @@ export class String {
var start = clamp<isize>(pos, 0, len);
var searchLength: isize = searchString.length;
if (searchLength + start > len) return false;
return !compareUTF16(
changetype<usize>(this) + (start << 1),
changetype<usize>(searchString),
searchLength
);
return !compareUnsafe(this, start, searchString, 0, searchLength);
}
substr(start: i32, length: i32 = i32.MAX_VALUE): String {
@ -309,19 +258,11 @@ export class String {
var intStart: isize = start;
var end: isize = length;
var size: isize = this.length;
if (intStart < 0) {
intStart = max<isize>(size + intStart, 0);
}
if (intStart < 0) intStart = max<isize>(size + intStart, 0);
var resultLength = clamp<isize>(end, 0, size - intStart);
if (resultLength <= 0) {
return EMPTY;
}
if (resultLength <= 0) return EMPTY;
var out = allocate(resultLength);
memory.copy(
changetype<usize>(out) + HEADER_SIZE,
changetype<usize>(this) + HEADER_SIZE + (intStart << 1),
<usize>resultLength << 1
);
copyUnsafe(out, 0, this, intStart, resultLength);
return out;
}
@ -333,18 +274,10 @@ export class String {
var from = min<i32>(finalStart, finalEnd);
var to = max<i32>(finalStart, finalEnd);
len = to - from;
if (!len) {
return EMPTY;
}
if (!from && to == this.length) {
return this;
}
if (!len) return EMPTY;
if (!from && to == this.length) return this;
var out = allocate(len);
memory.copy(
changetype<usize>(out) + HEADER_SIZE,
changetype<usize>(this) + HEADER_SIZE + (from << 1),
len << 1
);
copyUnsafe(out, 0, this, from, len);
return out;
}
@ -369,18 +302,10 @@ export class String {
) {
++start, --length;
}
if (!length) {
return EMPTY;
}
if (!start && length == this.length) {
return this;
}
if (!length) return EMPTY;
if (!start && length == this.length) return this;
var out = allocate(length);
memory.copy(
changetype<usize>(out) + HEADER_SIZE,
changetype<usize>(this) + HEADER_SIZE + (start << 1),
length << 1
);
copyUnsafe(out, 0, this, start, length);
return out;
}
@ -396,19 +321,11 @@ export class String {
) {
++start;
}
if (!start) {
return this;
}
if (!start) return this;
var outLen = len - start;
if (!outLen) {
return EMPTY;
}
if (!outLen) return EMPTY;
var out = allocate(outLen);
memory.copy(
changetype<usize>(out) + HEADER_SIZE,
changetype<usize>(this) + HEADER_SIZE + (start << 1),
outLen << 1
);
copyUnsafe(out, 0, this, start, outLen);
return out;
}
@ -423,18 +340,50 @@ export class String {
) {
--len;
}
if (len <= 0) {
return EMPTY;
}
if (<i32>len == this.length) {
return this;
}
if (len <= 0) return EMPTY;
if (<i32>len == this.length) return this;
var out = allocate(len);
memory.copy(
changetype<usize>(out) + HEADER_SIZE,
changetype<usize>(this) + HEADER_SIZE,
len << 1
);
copyUnsafe(out, 0, this, 0, len);
return out;
}
padStart(targetLength: i32, padString: String = changetype<String>(" ")): String {
assert(this !== null);
var length = this.length;
var padLen = padString.length;
if (targetLength < length || !padLen) return this;
var len = targetLength - length;
var out = allocate(targetLength);
if (len > padLen) {
let count = (len - 1) / padLen;
let base = count * padLen;
let rest = len - base;
repeatUnsafe(out, 0, padString, count);
if (rest) copyUnsafe(out, base, padString, 0, rest);
} else {
copyUnsafe(out, 0, padString, 0, len);
}
if (length) copyUnsafe(out, len, this, 0, length);
return out;
}
padEnd(targetLength: i32, padString: String = changetype<String>(" ")): String {
assert(this !== null);
var length = this.length;
var padLen = padString.length;
if (targetLength < length || !padLen) return this;
var len = targetLength - length;
var out = allocate(targetLength);
if (length) copyUnsafe(out, 0, this, 0, length);
if (len > padLen) {
let count = (len - 1) / padLen;
let base = count * padLen;
let rest = len - base;
repeatUnsafe(out, length, padString, count);
if (rest) copyUnsafe(out, base + length, padString, 0, rest);
} else {
copyUnsafe(out, length, padString, 0, len);
}
return out;
}
@ -451,20 +400,7 @@ export class String {
if (count === 1) return this;
var result = allocate(length * count);
var strLen = length << 1;
/*
* TODO possible improvments: reuse existing result for exponentially concats like:
* 'a' + 'a' => 'aa' + 'aa' => 'aaaa' + 'aaaa' etc
*/
for (let offset = 0, len = strLen * count; offset < len; offset += strLen) {
memory.copy(
changetype<usize>(result) + HEADER_SIZE + offset,
changetype<usize>(this) + HEADER_SIZE,
strLen
);
}
repeatUnsafe(result, 0, this, count);
return result;
}
@ -551,24 +487,19 @@ export function parseI64(str: String, radix: i32 = 0): i64 {
// FIXME: naive implementation
export function parseFloat(str: String): f64 {
var len: i32 = str.length;
if (!len) {
return NaN;
}
if (!len) return NaN;
var ptr = changetype<usize>(str) /* + HEAD -> offset */;
var code = <i32>load<u16>(ptr, HEADER_SIZE);
// determine sign
var sign: f64;
if (code == CharCode.MINUS) {
if (!--len) {
return NaN;
}
if (!--len) return NaN;
code = <i32>load<u16>(ptr += 2, HEADER_SIZE);
sign = -1;
} else if (code == CharCode.PLUS) {
if (!--len) {
return NaN;
}
if (!--len) return NaN;
code = <i32>load<u16>(ptr += 2, HEADER_SIZE);
sign = 1;
} else {
@ -588,9 +519,7 @@ export function parseFloat(str: String): f64 {
assert(false); // TODO
}
code -= CharCode._0;
if (<u32>code > 9) {
break;
}
if (<u32>code > 9) break;
num += <f64>code * fac;
fac *= 0.1;
ptr += 2;
@ -598,9 +527,7 @@ export function parseFloat(str: String): f64 {
break;
}
code -= CharCode._0;
if (<u32>code >= 10) {
break;
}
if (<u32>code >= 10) break;
num = (num * 10) + code;
ptr += 2;
}

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@ -290,14 +290,21 @@ declare class String {
private constructor();
charAt(index: i32): string;
charCodeAt(index: i32): i32;
concat(other: string): string;
indexOf(other: string, fromIndex?: i32): i32;
lastIndexOf(other: string, fromIndex?: i32): i32;
includes(other: string): bool;
charAt(index: i32): string;
charCodeAt(index: i32): i32;
substring(from: i32, to?: i32): string;
startsWith(other: string): bool;
endsWith(other: string): bool;
substr(start: u32, length?: u32): string;
substring(from: i32, to?: i32): string;
trim(): string;
trimLeft(): string;
trimRight(): string;
padStart(targetLength: i32, padString?: string): string;
padEnd(targetLength: i32, padString?: string): string;
replace(search: string, replacement: string): string;
repeat(count?: i32): string;
toString(): string;