From fc4473e7410a03630b638ac087caf6e64b6a3508 Mon Sep 17 00:00:00 2001
From: David Sehnal <david.sehnal@gmail.com>
Date: Fri, 20 Oct 2017 02:24:30 +0200
Subject: [PATCH] simplified iterator
---
src/structure/collections/iterator.ts | 23 ++---------------------
src/structure/spec/collections.spec.ts | 2 +-
2 files changed, 3 insertions(+), 22 deletions(-)
diff --git a/src/structure/collections/iterator.ts b/src/structure/collections/iterator.ts
index 4e6072234..8dd89ed87 100644
--- a/src/structure/collections/iterator.ts
+++ b/src/structure/collections/iterator.ts
@@ -20,25 +20,6 @@ interface Iterator<T> {
nextValue(): T
}
-class EmptyIteratorImpl implements Iterator<any> {
- [Symbol.iterator]() { return this; }
- done = true;
- value = void 0;
- next() { return this; }
- nextValue() { return this.value; }
-}
-
-class SingletonIteratorImpl<T> implements Iterator<T> {
- private yielded = false;
-
- [Symbol.iterator]() { return this; }
- done = false;
- value: T;
- next() { this.done = this.yielded; this.yielded = true; return this; }
- nextValue() { return this.next().value; }
- constructor(value: T) { this.value = value; }
-}
-
class ArrayIteratorImpl<T> implements Iterator<T> {
private xs: ArrayLike<T> = [];
private index: number = -1;
@@ -87,9 +68,9 @@ class RangeIteratorImpl implements Iterator<number> {
}
namespace Iterator {
- export const Empty: Iterator<any> = new EmptyIteratorImpl();
- export function Singleton<T>(value: T): Iterator<T> { return new SingletonIteratorImpl(value); }
+ export const Empty: Iterator<any> = new RangeIteratorImpl(0, -1);
export function Array<T>(xs: ArrayLike<T>): Iterator<T> { return new ArrayIteratorImpl<T>(xs); }
+ export function Value(value: number): Iterator<number> { return new RangeIteratorImpl(value, value); }
export function Range(min: number, max: number): Iterator<number> { return new RangeIteratorImpl(min, max); }
export function toArray<T>(it: Iterator<T>): T[] {
diff --git a/src/structure/spec/collections.spec.ts b/src/structure/spec/collections.spec.ts
index 57e130ac8..6ade6097f 100644
--- a/src/structure/spec/collections.spec.ts
+++ b/src/structure/spec/collections.spec.ts
@@ -17,7 +17,7 @@ describe('basic iterators', () => {
}
check('empty', Iterator.Empty, []);
- check('singleton', Iterator.Singleton(10), [10]);
+ check('singleton', Iterator.Value(10), [10]);
check('array', Iterator.Array([1, 2, 3]), [1, 2, 3]);
check('range', Iterator.Range(0, 3), [0, 1, 2, 3]);
});
--
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