Mask matches in bit manipulation

Question

Here is a question related to bit manipulation(masks), I'm programming in Javascript. I want to do the following:

const entityMask1 = new MaskManager();
entityMask1.addElement(0);
entityMask1.addElement(1);
entityMask1.addElement(2);

let SOME_SYSTEM_MASK = 0;
SOME_SYSTEM_MASK |= (1 << 0); // -> 1
SOME_SYSTEM_MASK |= (1 << 1); // -> 3
SOME_SYSTEM_MASK |= (1 << 2); // -> 7
SOME_SYSTEM_MASK |= (1 << 3); // -> 15
SOME_SYSTEM_MASK |= (1 << 4); // -> 31

entityMask1.matcheAll(SOME_SYSTEM_MASK); // -> false
entityMask1.matchesOne(SOME_SYSTEM_MASK); // -> true
entityMask1.matchNoneOrMore(SOME_SYSTEM_MASK); // -> true
entityMask1.matchesNone(SOME_SYSTEM_MASK); // -> false

function MaskManager() {
    this.mask = 0;
}

MaskManager.prototype.addElement = function(element) {
    this.mask |= (1 << element);
}

MaskManager.prototype.delElement = function(element) {
    this.mask ^= (1 << element);
}

MaskManager.prototype.matchAll = function(targetMask) {
    return (this.mask === targetMask);
}

MaskManager.prototype.matchOne = function(targetMask) {
//    return ?;
}

MaskManager.prototype.matchNoneOrMore = function(targetMask) {
//    return ?;
}


MaskManager.prototype.matchNone = function(targetMask) {
//    return ?;
}

At where:

• matchAll - mask has all elements.
• matchOne - mask has at least one element.
• matchNoneOrMore - mask has none or more elements.
• matchNone - mask does not have these elements

Answer 1

I believe you have succeeded, so far no test went wrong. I think it's right what I did, but I can be with the vision overshadowed for some case, I hope not:

 const addElementInMask = (element, newElement) => (element |= (1 << newElement)); const maskEqualsTargetMask = (mask, targetMask) => mask === targetMask; const maskContainsAllElements = (mask, targetMask) => targetMask === (mask & targetMask); const maskContainsNoneElements = (mask, targetMask) => mask === (mask & ~targetMask); const maskContainsOneOrMoreElements = (mask, targetMask) => targetMask === (mask | targetMask) && !maskContainsNoneElements(mask, targetMask); const maskContainsNoneOrMoreElements = (mask, targetMask) => targetMask === true; const matchResult = (matchName, expression) => console.log(matchName+': '+expression); const element1 = 1; const element2 = 2; const element3 = 3; let mask = 0; mask = addElementInMask(mask, element1); mask = addElementInMask(mask, element2); let targetMask = 0; targetMask = addElementInMask(targetMask, element1); targetMask = addElementInMask(targetMask, element2); targetMask = addElementInMask(targetMask, element3); console.log('Expected: false, false, false, true, true'); matchResult('maskEqualsTargetMask', maskEqualsTargetMask(mask, targetMask)); matchResult('maskContainsAllElements', maskContainsAllElements(mask, targetMask)); matchResult('maskContainsNoneElements', maskContainsNoneElements(mask, targetMask)); matchResult('maskContainsOneOrMoreElements', maskContainsOneOrMoreElements(mask, targetMask)); matchResult('maskContainsNoneOrMoreElements', maskContainsNoneOrMoreElements(mask, targetMask)); 

Answer 2

MaskManager.prototype.matchOne = function(targetMask) {
    return ((this.mask & targetMask) !== 0);
}

MaskManager.prototype.matchNone = function(targetMask) {
    return ((this.mask ^ targetMask) === 0);
}

MaskManager.prototype.matchNoneOrMore = function(targetMask) {
    return true;
}