Bounded: add clamp, reverse

docs/modules/Bounded.ts.md

@@ -22,6 +22,9 @@ Added in v2.0.0
   - [~~boundedNumber~~](#boundednumber)
 - [type classes](#type-classes)
   - [Bounded (interface)](#bounded-interface)
+- [utils](#utils)
+  - [clamp](#clamp)
+  - [reverse](#reverse)
 
 ---
 
@@ -53,3 +56,29 @@ export interface Bounded<A> extends Ord<A> {
 ```
 
 Added in v2.0.0
+
+# utils
+
+## clamp
+
+Clamp a value between bottom and top values.
+
+**Signature**
+
+```ts
+export declare const clamp: <T>(B: Bounded<T>) => (a: T) => T
+```
+
+Added in v2.12.0
+
+## reverse
+
+Reverses the Ord of a bound and swaps top and bottom values.
+
+**Signature**
+
+```ts
+export declare const reverse: <T>(B: Bounded<T>) => Bounded<T>
+```
+
+Added in v2.12.0

src/Bounded.ts

@@ -7,7 +7,9 @@
  *
  * @since 2.0.0
  */
-import { Ord, ordNumber } from './Ord'
+import * as O from './Ord'
+
+import Ord = O.Ord
 
 // -------------------------------------------------------------------------------------
 // model
@@ -22,6 +24,34 @@ export interface Bounded<A> extends Ord<A> {
   readonly bottom: A
 }
 
+// -------------------------------------------------------------------------------------
+// utils
+// -------------------------------------------------------------------------------------
+
+/**
+ * Clamp a value between bottom and top values.
+ *
+ * @category utils
+ * @since 2.12.0
+ */
+export const clamp = <T>(B: Bounded<T>) => O.clamp(B)(B.bottom, B.top)
+
+/**
+ * Reverses the Ord of a bound and swaps top and bottom values.
+ *
+ * @category utils
+ * @since 2.12.0
+ */
+export const reverse = <T>(B: Bounded<T>): Bounded<T> => {
+  const R = O.reverse(B)
+  return {
+    equals: R.equals,
+    compare: R.compare,
+    top: B.bottom,
+    bottom: B.top
+  }
+}
+
 // -------------------------------------------------------------------------------------
 // deprecated
 // -------------------------------------------------------------------------------------
@@ -36,8 +66,8 @@ export interface Bounded<A> extends Ord<A> {
  * @deprecated
  */
 export const boundedNumber: Bounded<number> = {
-  equals: ordNumber.equals,
-  compare: ordNumber.compare,
+  equals: O.ordNumber.equals,
+  compare: O.ordNumber.compare,
   top: Infinity,
   bottom: -Infinity
 }

test/Bounded.ts

@@ -0,0 +1,27 @@
+import * as _ from '../src/Bounded'
+import * as N from '../src/number'
+import * as U from './util'
+
+describe('Bounded', () => {
+  it('clamp', () => {
+    const B: _.Bounded<number> = {
+      ...N.Ord,
+      top: 10,
+      bottom: 0
+    }
+    const clamp = _.clamp(B)
+    U.deepStrictEqual(clamp(5), 5)
+    U.deepStrictEqual(clamp(-1), 0)
+    U.deepStrictEqual(clamp(11), 10)
+  })
+
+  it('reverse', () => {
+    const B: _.Bounded<number> = _.reverse({
+      ...N.Ord,
+      top: 10,
+      bottom: 0
+    })
+    U.deepStrictEqual(B.top, 0)
+    U.deepStrictEqual(B.bottom, 10)
+  })
+})