added IntervalIterator

src/mol-data/util/_spec/interval-iterator.spec.ts

+/**
+ * Copyright (c) 2018 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ *
+ * @author Alexander Rose <alexander.rose@weirdbyte.de>
+ */
+
+import { Interval, OrderedSet, SortedArray } from '../../int';
+import { IntervalIterator } from '../interval-iterator';
+
+ describe('interval', () => {
+    function testIterator(name: string, interval: Interval, set: OrderedSet, expectedValues: { index: number[], start: number[], end: number[]}) {
+        it(`iterator, ${name}`, () => {
+            const intervalIt = new IntervalIterator(interval, set)
+            const { index, start, end } = expectedValues
+    
+            let i = 0
+            while (intervalIt.hasNext) {
+                const segment = intervalIt.move()
+                expect(segment.index).toBe(index[i])
+                expect(segment.start).toBe(start[i])
+                expect(segment.end).toBe(end[i])
+                ++i
+            }
+            expect(i).toBe(index.length)
+        })
+    }
+
+    testIterator('basic',
+        Interval.ofRange(0, 5),
+        SortedArray.ofSortedArray([1, 3, 7, 8]),
+        { index: [1, 3], start: [0, 1], end: [1, 2] }
+    )
+});
\ No newline at end of file

src/mol-data/util/interval-iterator.ts

+/**
+ * Copyright (c) 2018 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ *
+ * @author Alexander Rose <alexander.rose@weirdbyte.de>
+ */
+
+ import Iterator from '../iterator'
+import { OrderedSet, Interval, Segmentation } from '../int';
+
+/** Emits a segment of length one for each element in the interval that is also in the set */
+export class IntervalIterator<T extends number = number> implements Iterator<Segmentation.Segment<T>> {
+    private value: Segmentation.Segment<T> = { index: 0, start: 0 as T, end: 0 as T }
+
+    private curIndex = 0
+    private maxIndex = 0
+
+    hasNext: boolean = false;
+
+    updateValue() {
+        this.value.index = this.curIndex
+        this.value.start = OrderedSet.findPredecessorIndex(this.set, Interval.getAt(this.interval, this.curIndex)) as  T
+        this.value.end = this.value.start + 1 as T 
+    }
+
+    move() {
+        if (this.hasNext) {
+            this.updateValue()
+            while (this.curIndex <= this.maxIndex) {
+                ++this.curIndex
+                if (OrderedSet.has(this.set, this.curIndex)) break
+            }
+            this.hasNext = this.curIndex <= this.maxIndex
+        }
+        return this.value;
+    }
+
+    constructor(private interval: Interval<T>, private set: OrderedSet<T>) {
+        if (Interval.size(interval)) {
+            this.curIndex = Interval.findPredecessorIndex(interval, OrderedSet.min(set))
+            this.maxIndex = Interval.findPredecessorIndex(interval, OrderedSet.max(set))
+        }
+
+        this.hasNext = OrderedSet.areIntersecting(this.interval, this.set)
+    }
+}
\ No newline at end of file