Add String#repeat method

std/assembly.d.ts

@@ -373,6 +373,8 @@ declare class String {
  trim(): string;
  trimLeft(): string;
  trimRight(): string;
+ repeat(count?: i32): string;
+ toString(): string;
 }
 
 /** Class for representing a runtime error. Base class of all errors. */

std/assembly/string.ts

@@ -131,7 +131,9 @@ export class String {
 
  @operator(">")
  private static __gt(left: String, right: String): bool {
- if (left === null || right === null) return false;
+ if (left === right || left === null || right === null) {
+ return false;
+ }
 
  var leftLength = left.length;
  var rightLength = right.length;
@@ -149,8 +151,9 @@ export class String {
 
  @operator(">=")
  private static __gte(left: String, right: String): bool {
+ if (left === right) return true;
  if (left === null) return right === null;
- else if (right === null) return false;
+ if (right === null) return false;
 
  var leftLength = left.length;
  var rightLength = right.length;
@@ -168,7 +171,9 @@ export class String {
 
  @operator("<")
  private static __lt(left: String, right: String): bool {
- if (left === null || right === null) return false;
+ if (left === right || left === null || right === null) {
+ return false;
+ }
 
  var leftLength = left.length;
  var rightLength = right.length;
@@ -186,6 +191,7 @@ export class String {
 
  @operator("<=")
  private static __lte(left: String, right: String): bool {
+ if (left === right) return true;
  if (left === null) return right === null;
  else if (right === null) return false;
 
@@ -377,6 +383,40 @@ export class String {
  );
  return out;
  }
+
+ repeat(count: i32 = 0): String {
+ assert(this !== null);
+ var length = this.length;
+
+ // Most browsers can't handle strings 1 << 28 chars or longer
+ if (count < 0 || length * count > (1 << 28)) {
+ throw new RangeError("Invalid count value");
+ }
+
+ if (count === 0 || !length) return EMPTY;
+ 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) {
+ move_memory(
+ changetype<usize>(result) + HEADER_SIZE + offset,
+ changetype<usize>(this) + HEADER_SIZE,
+ strLen
+ );
+ }
+
+ return result;
+ }
+
+ toString(): String {
+ return this;
+ }
 }
 
 export function parseInt(str: String, radix: i32 = 0): f64 {

std/portable.d.ts

@@ -247,12 +247,16 @@ declare class Float32Array extends Array<f32> {}
 declare class Float64Array extends Array<f64> {}
 
 declare class String {
+
  static fromCharCode(ls: i32, hs?: i32): string;
  static fromCharCodes(arr: u16[]): string;
  static fromCodePoint(cp: i32): string;
  static fromCodePoints(arr: i32[]): string;
+
  readonly length: i32;
+
  private constructor();
+
  indexOf(subject: string, position?: i32): i32;
  includes(other: string): bool;
  lastIndexOf(subject: string, position?: i32): i32;
@@ -262,6 +266,7 @@ declare class String {
  startsWith(subject: string): bool;
  endsWith(subject: string): bool;
  replace(search: string, replacement: string): string;
+ repeat(count?: i32): string;
  toString(): string;
 }
 

tests/compiler/std/array-access.optimized.wat

@@ -125,7 +125,7 @@
  (call $abort
  (i32.const 0)
  (i32.const 8)
- (i32.const 232)
+ (i32.const 238)
  (i32.const 4)
  )
  (unreachable)

tests/compiler/std/array-access.untouched.wat

@@ -195,7 +195,7 @@
  (call $abort
  (i32.const 0)
  (i32.const 8)
- (i32.const 232)
+ (i32.const 238)
  (i32.const 4)
  )
  (unreachable)