lens.ts - npm Package Compare versions

Comparing version 0.2.0 to 0.2.1

dist/index.d.ts

@@ -10,8 +10,2 @@ export declare class Lens<T, U> {
 }
-export declare class KeyLens<T, K extends keyof T> extends Lens<T, T[K]> {
-    constructor(key: K);
-}
-export declare class IndexLens<E> extends Lens<Array<E>, E> {
-    constructor(idx: number);
-}
 export declare function lens<T>(): Lens<T, T>;

dist/index.js

 "use strict";
-var __extends = (this && this.__extends) || (function () {
-    var extendStatics = Object.setPrototypeOf ||
-        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
-        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
-    return function (d, b) {
-        extendStatics(d, b);
-        function __() { this.constructor = d; }
-        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
-    };
-})();
 Object.defineProperty(exports, "__esModule", { value: true });
@@ -19,3 +9,3 @@ var Lens = /** @class */ (function () {
     Lens.prototype.k = function (key) {
-        return this.compose(new KeyLens(key));
+        return this.compose(keyL(key));
     };
@@ -34,23 +24,26 @@ Lens.prototype.compose = function (other) {
 Lens.prototype.i = function (idx) {
-    return this.compose(new IndexLens(idx));
+    // implementation is the same as .k()
+    return this.compose(keyL(idx));
 };
-var KeyLens = /** @class */ (function (_super) {
-    __extends(KeyLens, _super);
-    function KeyLens(key) {
-        return _super.call(this, function (t) { return t[key]; }, function (v) { return function (t) {
-            return Object.assign({}, t, (_a = {}, _a[key] = v, _a));
-            var _a;
-        }; }) || this;
+function copy(x) {
+    if (Array.isArray(x)) {
+        return x.map(function (e) { return e; });
     }
-    return KeyLens;
-}(Lens));
-exports.KeyLens = KeyLens;
-var IndexLens = /** @class */ (function (_super) {
-    __extends(IndexLens, _super);
-    function IndexLens(idx) {
-        return _super.call(this, function (t) { return t[idx]; }, function (v) { return function (t) { return t.map(function (_v, _i) { return _i === idx ? v : _v; }); }; }) || this;
+    else if (x && typeof x === 'object') {
+        return Object.keys(x).reduce(function (res, k) {
+            res[k] = x[k];
+            return res;
+        }, {});
     }
-    return IndexLens;
-}(Lens));
-exports.IndexLens = IndexLens;
+    else {
+        return x;
+    }
+}
+function keyL(prop) {
+    return new Lens(function (t) { return t[prop]; }, function (v) { return function (t) {
+        var copied = copy(t);
+        copied[prop] = v;
+        return copied;
+    }; });
+}
 function lens() {
@@ -57,0 +50,0 @@ return new Lens(function (t) { return t; }, function (v) { return function (t) { return v; }; });

package.json

 {
   "name": "lens.ts",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "TypeScript Lens implementation",
@@ -5,0 +5,0 @@ "main": "dist/index.js",

README.md

@@ -83,8 +83,3 @@ # lens.ts [![travis-ci](https://travis-ci.org/utatti/lens.ts.svg?branch=master)](https://travis-ci.org/utatti/lens.ts)
 ``` typescript
-import {
-  lens,
-  Lens,
-  KeyLens,
-  IndexLens
-} from 'lens.ts';
+import { lens, Lens } from 'lens.ts';
 ```
@@ -106,2 +101,4 @@
 
+Usually, you don't need to import `Lens` directly.
+
 ``` typescript
@@ -120,3 +117,3 @@ class Lens<T, U> {
 
-Retrives an actual value from an actual source.
+Retrive an actual value from an actual source.
 
@@ -159,3 +156,3 @@ ``` typescript
 
-Composes 2 lenses into one.
+Compose 2 lenses into one.
 
@@ -171,3 +168,3 @@ ``` typescript
 
-A helper method to narrow the lens for a property of `U`.
+Narrow the lens for a property of `U`.
 
@@ -180,5 +177,2 @@ ``` typescript
 lens.k('name') // :: Lens<Person, string>
-
-// ↑ is a shortcut for ↓
-lens.compose(new KeyLens<Person, 'name'>('name'))
 ```
@@ -188,4 +182,4 @@
 
-A helper method to narrow the lens for an element of an array `U`. A type error
-is thrown if `U` is not an array.
+Narrow the lens for an element of an array `U`. A type error is thrown if `U` is
+not an array.
 
@@ -196,19 +190,6 @@ ``` typescript
 lens.i(10) // :: Lens<T, E>
-
-// ↑ is *roughly* a shortcut for ↓
-lens.compose(new IndexLens<E>(10))
 ```
 
-### `KeyLens`, `IndexLens`
-
-They are exported for the references of the `.k()` and `.i()` methods above, but
-it's not recommended using them by themselves. Please use the helper methods.
-
-``` typescript
-lens().k('name') // instead of .compose(new KeyLens('name'))
-lens().i(10) // instead of .compose(new IndexLens(10))
-```
-
 ## License
 
 [MIT](LICENSE)

src/index.ts

@@ -9,3 +9,3 @@ export class Lens<T, U> {
   public k<K extends keyof U>(key: K): Lens<T, U[K]> {
-    return this.compose(new KeyLens(key));
+    return this.compose(keyL(key));
   }
@@ -29,21 +29,28 @@
 Lens.prototype.i = function(idx) {
-  return this.compose(new IndexLens(idx));
+  // implementation is the same as .k()
+  return this.compose(keyL(idx as any));
 };
 
-export class KeyLens<T, K extends keyof T> extends Lens<T, T[K]> {
-  constructor(key: K) {
-    super(
-      t => t[key],
-      v => t => Object.assign({}, t, { [key]: v })
-    );
+function copy<T>(x: T): T {
+  if (Array.isArray(x)) {
+    return x.map(e => e) as any;
+  } else if (x && typeof x === 'object') {
+    return Object.keys(x).reduce((res, k) => {
+      res[k] = (x as any)[k];
+      return res;
+    }, {} as any);
+  } else {
+    return x;
   }
 }
 
-export class IndexLens<E> extends Lens<Array<E>, E> {
-  constructor(idx: number) {
-    super(
-      t => t[idx],
-      v => t => t.map((_v, _i) => _i === idx ? v : _v)
-    );
-  }
+function keyL<T, K extends keyof T>(prop: K): Lens<T, T[K]> {
+  return new Lens(
+    t => t[prop],
+    v => t => {
+      const copied = copy(t);
+      copied[prop] = v;
+      return copied;
+    }
+  );
 }
@@ -50,0 +57,0 @@

No alert changes

Worsened metrics

Total package byte prevSize

8876

decreased by-12.35%

Lines of code

110

decreased by-5.17%

Number of lines in readme file

188

decreased by-9.18%

No dependency changes