Merge pull request #29 from will-path/patch-1

Add hasAnyInRange to TypedFastBitSet

Author: lemire

src/BitSet.range.spec.ts

@@ -1,5 +1,6 @@
 import { bitsetTest } from "./testUtils";
 import { SparseTypedFastBitSet } from "./SparseTypedFastBitSet";
+import { TypedFastBitSet } from "./TypedFastBitSet";
 
 describe("sparse biggest logic", () => {
   it("Testing sparse addRange/removeRange", () => {
@@ -25,6 +26,27 @@ describe("sparse biggest logic", () => {
   });
 });
 
+describe("fixed bitset logic", () => {
+  it("Testing has any in range", () => {
+    const b1 = new TypedFastBitSet();
+    b1.addRange(100, 200);
+    b1.addRange(230, 250);
+    expect(b1.hasAnyInRange(0, 100)).toBe(false); // before
+    expect(b1.hasAnyInRange(200, 204)).toBe(false); // endword === firstword
+    expect(b1.hasAnyInRange(200, 229)).toBe(false); // gaps
+    expect(b1.hasAnyInRange(250, 300)).toBe(false); // after
+    expect(b1.hasAnyInRange(99, 101)).toBe(true); // across start 1
+    expect(b1.hasAnyInRange(99, 140)).toBe(true); // across start 2
+    expect(b1.hasAnyInRange(99, 201)).toBe(true); // across start/end
+    expect(b1.hasAnyInRange(100, 140)).toBe(true); // start
+    expect(b1.hasAnyInRange(100, 200)).toBe(true); // start past end
+    expect(b1.hasAnyInRange(101, 198)).toBe(true); // inside
+    expect(b1.hasAnyInRange(120, 121)).toBe(true); // smol
+    expect(b1.hasAnyInRange(197, 200)).toBe(true); // end
+    expect(b1.hasAnyInRange(199, 210)).toBe(true); // across end
+  });
+});
+
 bitsetTest(({ name, build, arrayEqual }) => {
   describe(name, () => {
     it("Testing add Range", () => {

src/TypedFastBitSet.ts

@@ -169,6 +169,24 @@ export class TypedFastBitSet implements BitSet {
     return (this.words[index >>> 5] & (1 << index)) !== 0;
   }
 
+  /**
+   * Is any value of the (exclusive) range contained in the set?
+   */
+  hasAnyInRange(start: number, end: number): boolean {
+    if (start >= end) return false;
+    const words = this.words;
+    start = Math.min(start, (words.length << 5) - 1);
+    end = Math.min(end, (words.length << 5) - 1);
+    const firstword = start >>> 5;
+    const endword = (end - 1) >> 5;
+    if (firstword === endword)
+      return (words[firstword] & ((~0 << start) & (~0 >>> -end))) !== 0;
+    if ((words[firstword] & (~0 << start)) !== 0) return true;
+    for (let index = firstword + 1; index < endword - 1; index++)
+      if (words[index] !== 0) return true;
+    return (words[endword] & (~0 >>> -end)) !== 0;
+  }
+
   /**
    * Tries to add the value (Set the bit at index to true)
    *