Add lite version

Author: kethan

README.md

@@ -2,11 +2,16 @@
 
 [![tests](https://github.com/kethan/usub/actions/workflows/node.js.yml/badge.svg)](https://github.com/kethan/usub/actions/workflows/node.js.yml) [![Version](https://img.shields.io/npm/v/usub.svg?color=success&style=flat-square)](https://www.npmjs.com/package/usub) [![Badge size](https://deno.bundlejs.com/badge?q=usub&treeshake=[*]&config={"compression":"brotli"})](https://unpkg.com/usub) [![Badge size](https://deno.bundlejs.com/badge?q=usub&treeshake=[*]&config={"compression":"gzip"})](https://unpkg.com/usub)
 
+#### lite
+
+[![Badge size](https://deno.bundlejs.com/badge?q=usub/lite&treeshake=[*]&config={"compression":"brotli"})](https://unpkg.com/usub/lite) [![Badge size](https://deno.bundlejs.com/badge?q=usub/lite&treeshake=[*]&config={"compression":"gzip"})](https://unpkg.com/usub/lite)
+
 This javascript library provides utility functions for handling observables, signals, and asynchronous data streams across various reactive programming libraries. It supports flexible customization to integrate with different libraries, ensuring seamless subscription management and automatic cleanup.
 
 ## Table of Contents
 
 -   [Installation](#installation)
+-   [Lite](#lite)
 -   [Usage](#usage)
     -   [Basic Setup](#basic-setup)
     -   [Promise](#promise)
@@ -46,6 +51,22 @@ To use this utility, simply import it into your project:
 import { is, api, sub, get } from "usub";
 ```
 
+### lite
+
+The lite utility does not contain subscribe, and set method for observ-* patterns.
+
+**cdn**: https://unpkg.com/usub/lite
+
+**es**: https://unpkg.com/usub/lite?module
+
+## Installation
+
+To use lite version, simply import it into your project:
+
+```js
+import { is, api, sub, get } from "usub/lite";
+```
+
 ## Usage
 
 ### Basic Setup

lite/index.js

@@ -0,0 +1,54 @@
+const
+    // FinalizationRegistry to clean up subscriptions when objects are garbage collected
+    registry = new FinalizationRegistry(unsub => (unsub && unsub?.call?.())),
+
+    // API object providing basic functions for handling effects and values
+    api = {
+        // Handle any reactive subscription
+        any: undefined,
+        // If any cleanup is requested
+        cleanup: undefined,
+        // Executes the provided function
+        effect: (f) => f(),
+        // Returns false for any value (placeholder implementation)
+        is: (v) => v?.call,
+        // Retrieves the value (returns it as is)
+        get: (v) => v?.call(),
+    },
+
+    // Utility function to handle and unwrap values of signals, observable, etc especially functions
+    get = (v) => api.is(v) ? get(api.get(v)) : v?.call ? get(v()) : v,
+
+    // Checks if the argument is considered an observable
+    is = (arg) => arg && !!(
+        arg[Symbol.asyncIterator] ||     // Async iterator
+        arg[Symbol.iterator] ||          // Sync iterator
+        arg.then ||                      // Promise
+        api.is(arg) ||                   // Custom observable check
+        arg.call                         // Function
+    ),
+    // Subscribe to an observable or value, and provide a callback for each value
+    sub = (target, stop, unsub) => (next, error, cleanup) => target && (
+        unsub = ((!api?.any && (api.is(target) || target?.call)) && api.effect(() => (next(get(target)), api?.cleanup?.(cleanup), cleanup))) ||
+        (
+            target.then?.(v => (!stop && next(get(v)), cleanup?.()), error) ||
+            (target[Symbol.asyncIterator] || target[Symbol.iterator]) && (async v => {
+                try {
+                    // FIXME: possible drawback: it will catch error happened in next, not only in iterator
+                    for await (v of target) { if (stop) return; next(get(v)) }
+                    cleanup?.()
+                } catch (err) { error?.(err) }
+            })()
+        ) && (_ => stop = 1) ||
+        (api?.any?.(target)?.(next, error, cleanup)),
+        // register autocleanup
+        registry.register(target, unsub),
+        unsub
+    );
+
+export {
+    api,
+    is,
+    sub,
+    get
+}

package.json

@@ -1,26 +1,37 @@
 {
 	"name": "usub",
 	"description": "Subscribe to any reactive sources",
-	"version": "0.3.2",
+	"version": "0.4.0",
 	"type": "module",
 	"source": "./src/index.js",
 	"main": "./dist/index.js",
 	"module": "./dist/index.es.js",
 	"unpkg": "./dist/index.min.js",
 	"umd:main": "./dist/index.umd.js",
 	"exports": {
-		"browser": "./dist/index.es.js",
-		"umd": "./dist/index.umd.js",
-		"require": "./dist/index.js",
-		"import": "./dist/index.es.js",
-		"default": "./dist/index.es.js"
+		".": {
+			"browser": "./dist/index.es.js",
+			"umd": "./dist/index.umd.js",
+			"require": "./dist/index.js",
+			"import": "./dist/index.es.js",
+			"default": "./dist/index.es.js"
+		},
+		"./lite": {
+			"browser": "./lite/dist/index.es.js",
+			"umd": "./lite/dist/index.umd.js",
+			"require": "./lite/dist/index.js",
+			"import": "./lite/dist/index.es.js",
+			"default": "./lite/dist/index.es.js"
+		},
+		"./package.json": "./package.json"
 	},
 	"repository": {
 		"type": "git",
 		"url": "git+https://github.com/kethan/usub.git"
 	},
 	"files": [
-		"dist"
+		"dist",
+		"lite"
 	],
 	"scripts": {
 		"build": "rollup --config rollup.config.js",

rollup.config.js

@@ -36,4 +36,5 @@ const resolve = (pkg, input = "src/index", output = "dist/index") => ({
 
 export default [
 	resolve("usub"),
+	resolve("usub", "lite/index", "lite/dist/index")
 ]

src/index.js

@@ -53,7 +53,7 @@ const
                 } catch (err) { error?.(err) }
             })()
         ) && (_ => stop = 1) ||
-        (api?.any?.(target)?.(next, cleanup, error)),
+        (api?.any?.(target)?.(next, error, cleanup)),
         // register autocleanup
         registry.register(target, unsub),
         unsub