list.reject

src/prelude/list.ts

@@ -14,6 +14,13 @@ export const list = {
     }
     return acc
   },
+  reject: async (list: any[], cb: Function) => {
+    let acc: any[] = []
+    for (const value of list) {
+      if (!(await cb(value))) acc.push(value)
+    }
+    return acc
+  },
   reduce: async (list: any[], cb: Function, initial: any) => {
     let acc = initial
     for (const value of list) acc = await cb(acc, value)

src/prelude/tests/prelude.test.ts

@@ -193,6 +193,15 @@ describe('collections', () => {
     `).toEvaluateTo([3, 4, 5])
   })
 
+  test('list.reject doesnt keep matching elements', async () => {
+    await expect(`
+      is-even = do x:
+        (x % 2) == 0
+      end
+      list.reject [1 2 3 4 5] is-even
+    `).toEvaluateTo([1, 3, 5])
+  })
+
   test('list.reduce accumulates values', async () => {
     await expect(`
       add = do acc x: