[init]

.gitignore

@@ -0,0 +1 @@
+node_modules

index.js

@@ -0,0 +1,5 @@
+'use strict';
+
+const Slider = require('./structures/slider');
+
+module.exports = Slider;

package.json

@@ -0,0 +1,29 @@
+{
+  "name": "@codefeathers/window",
+  "version": "0.0.1",
+  "description": "A sliding window algorithm to insert a new array into an existing one.",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/codefeathers/sliding-window.git"
+  },
+  "keywords": [
+    "sliding-window",
+    "insertion",
+    "algorithm",
+    "array",
+    "javascript"
+  ],
+  "author": "Muthu Kumar @MKRhere <https://mkr.pw>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/codefeathers/sliding-window/issues"
+  },
+  "homepage": "https://github.com/codefeathers/sliding-window#readme",
+  "dependencies": {
+    "@codefeathers/iseq": "^1.1.0"
+  }
+}

structures/slider.js

@@ -0,0 +1,41 @@
+'use strict';
+
+const isEq = require('@codefeathers/iseq/isEq');
+
+const Window = require('./window');
+
+const wrap = (f, ...x) => (...y) => f(...x, ...y);
+
+class Slider {
+	constructor (options) {
+		this.windowSize = options.window;
+		this.prefer = options.prefer;
+		this.accepting = options.accepting;
+	}
+
+	slide (to, from) {
+		const k = this.windowSize;
+		const host = new Window(...to);
+		const guest = new Window(...from);
+		const recurse = (window, i) => {
+			let x, y, z;
+			x = host.findIndex(wrap(isEq, window[0]));
+			let switcher = true;
+			if(x !== -1)
+				for (let j = 1; j < window.length; j++)
+					if(host.findIndexAfter(x, wrap(isEq, window[j])) === -1) {
+						switcher = false;
+						break;
+					}
+			if(switcher) return [ x, i ];
+			const newWindow = new Window(...guest.slice(++i, k));
+			if(newWindow.length !== 0 && newWindow.length === k) return recurse(newWindow, i);
+			return [ -1, -1 ];
+		};
+		const window = new Window(...guest.slice(0, k));
+		const index = recurse(window, 0);
+		return index;
+	}
+};
+
+module.exports = Slider;

structures/window.js

@@ -0,0 +1,36 @@
+class Window extends Array {
+
+	constructor (...args) {
+		if(args.length === 1) return args;
+		return super(...args);
+	}
+
+	recurse (fn) {
+		let index = 0;
+		const call = (arr, acc = []) => {
+			if(arr[0]) {
+				const res = fn(index++, arr[0]);
+				return call(arr.slice(1), [ res, ...acc ]);
+			}
+			return acc;
+		};
+		return call(this);
+	}
+
+	findIndexAfter(index, predicate) {
+		const self = this;
+		let i = index + 1;
+		while(i < self.length) {
+			if(predicate(self[i])) return i;
+			i++;
+		}
+		return -1;
+	}
+
+	empty () {
+		this.recurse(i => this.splice(i));
+		return this;
+	}
+};
+
+module.exports = Window;