Add Set.removeValues function (#23)

Author: jeparlefrancais

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Changelog
 
+- add `Set.removeValues` ([#23](https://github.com/seaofvoices/luau-disk/pull/23))
 - add `Set.filter` ([#22](https://github.com/seaofvoices/luau-disk/pull/22))
 - add `Set.count` and `Set.isEmpty` ([#21](https://github.com/seaofvoices/luau-disk/pull/21))
 - add `Set.map` ([#20](https://github.com/seaofvoices/luau-disk/pull/20))

docs/Set.md

@@ -13,6 +13,7 @@ If you are not familiar with this kind of utility functions, don't get overwhelm
 - [count](#count)
 - [fromArray](#fromarray)
 - [merge](#merge)
+- [removeValues](#removeValues)
 
 ## count
 
@@ -37,6 +38,8 @@ end)
 -- result is { 2 = true, 4 = true, 6 = true }
 ```
 
+*Related [removeValues](#removevalues)*
+
 ## fromArray
 
 Creates a new Set from an array of values.
@@ -81,3 +84,17 @@ local result = Set.merge(set1, set2)
 ```
 
 The function will skip `nil` values when merging.
+
+## removeValues
+
+Returns a new set with all the given values removed.
+
+```lua
+local set = Set.fromArray({ "a", "b", "c" })
+local result = Set.removeValues(set, "b")
+-- result is { a = true, c = true }
+```
+
+**Note:** This function returns the same set if no values are given or if the values to remove are not in the set.
+
+*Related [filter](#filter)*

src/init.lua

@@ -73,6 +73,7 @@ local Disk = {
         isEmpty = require('./set/isEmpty'),
         map = require('./set/map'),
         merge = require('./set/merge'),
+        removeValues = require('./set/removeValues'),
     },
     None = require('./None'),
     WeakMap = require('./WeakMap'),

src/set/__tests__/removeValues.test.lua

@@ -0,0 +1,51 @@
+local jestGlobals = require('@pkg/@jsdotlua/jest-globals')
+
+local fromArray = require('../fromArray')
+local removeValues = require('../removeValues')
+
+local expect = jestGlobals.expect
+local it = jestGlobals.it
+
+it('removes single value from set', function()
+    local set = fromArray({ 1, 2, 3, 4, 5 })
+    local result = removeValues(set, 3)
+
+    expect(result).toEqual(fromArray({ 1, 2, 4, 5 }))
+end)
+
+it('removes multiple values from set', function()
+    local set = fromArray({ 1, 2, 3, 4, 5 })
+    local result = removeValues(set, 2, 4)
+
+    expect(result).toEqual(fromArray({ 1, 3, 5 }))
+end)
+
+it('returns original set when no values to remove', function()
+    local set = fromArray({ 1, 2, 3, 4, 5 })
+    local result = removeValues(set)
+
+    expect(result).toEqual(fromArray({ 1, 2, 3, 4, 5 }))
+end)
+
+it('returns original set when set is empty', function()
+    local set = fromArray({})
+    local result = removeValues(set, 1, 2, 3)
+
+    expect(result).toBe(set)
+end)
+
+it('returns original set when values to remove are not in set', function()
+    local set = fromArray({ 1, 2, 3, 4, 5 })
+    local result = removeValues(set, 6, 7, 8)
+
+    expect(result).toBe(set)
+end)
+
+it('handles nil values in remove list', function()
+    local set = fromArray({ 1, 2, 3, 4, 5 })
+    local result = removeValues(set, 2, nil, 4)
+
+    expect(result).toEqual(fromArray({ 1, 3, 5 }))
+end)
+
+return nil

src/set/removeValues.lua

@@ -0,0 +1,29 @@
+local SetType = require('./type')
+local isEmpty = require('./isEmpty')
+
+type Set<T> = SetType.Set<T>
+
+local function removeValues<T>(set: Set<T>, ...: T?): Set<T>
+    local removeLength = select('#', ...)
+
+    if removeLength == 0 or isEmpty(set) then
+        return set
+    end
+
+    local result
+
+    for i = 1, removeLength do
+        local value: T? = select(i, ...)
+
+        if value ~= nil and set[value] ~= nil then
+            if result == nil then
+                result = table.clone(set)
+            end
+            result[value] = nil
+        end
+    end
+
+    return result or set
+end
+
+return removeValues