feat: add product function

kantord · Oct 20, 2018 · 8da5fa4 · 8da5fa4
1 parent 9bfa159
commit 8da5fa4
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Showing 2 changed files with 19 additions and 2 deletions.
diff --git a/src/__tests__/builtins.test.js b/src/__tests__/builtins.test.js
@@ -14,7 +14,8 @@ const {
   keys,
   split,
   values,
-  combinations
+  combinations,
+  product
 } = builtIns
 
 describe('built ins', () => {
@@ -190,4 +191,16 @@ describe('built ins', () => {
       ])
     })
   })
+
+  describe('product', () => {
+    it('returns correct value', () => {
+      expect(product([['a', 'b'], []])).toEqual([])
+      expect(product([['a', 'b'], ['1', '2']])).toEqual([
+        ['a', '1'],
+        ['a', '2'],
+        ['b', '1'],
+        ['b', '2']
+      ])
+    })
+  })
 })
diff --git a/src/builtins.js b/src/builtins.js
@@ -1,6 +1,7 @@
 // @flow
 
 import { combinations } from '@aureooms/js-itertools/lib/map/combinations.js'
+import { product } from '@aureooms/js-itertools/lib/map/product.js'
 
 type ProjectableType = Array<mixed> & {[string]: mixed};
 type ProjectionRuleType = number & string;
@@ -93,5 +94,8 @@ export default {
 
   combinations: (r: number): Array<mixed> | (string => Array<Array<mixed>>) => (
     input: Array<mixed> | string
-  ): Array<Array<mixed>> => Array.from(combinations(input, r))
+  ): Array<Array<mixed>> => Array.from(combinations(input, r)),
+
+  product: (input: Array<mixed> | string): Array<Array<mixed>> =>
+    Array.from(product(input))
 }