Add ngrams operation

src/core/config/Categories.json

@@ -320,7 +320,8 @@
             "Unescape string",
             "Pseudo-Random Number Generator",
             "Sleep",
-            "File Tree"
+            "File Tree",
+            "N-gram"
         ]
     },
     {

src/core/operations/Ngram.mjs

@@ -0,0 +1,60 @@
+/**
+ * @author benjcal [benj.calderon@gmail.com]
+ * @copyright Crown Copyright 2024
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import {JOIN_DELIM_OPTIONS} from "../lib/Delim.mjs";
+
+/**
+ * ngram operation
+ */
+class Ngram extends Operation {
+
+    /**
+     * Ngram constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "N-gram";
+        this.module = "Default";
+        this.description = "Extracts n-grams from the input text. N-grams are contiguous sequences of n characters from a given text sample.";
+        this.infoURL = "https://wikipedia.org/wiki/N-gram";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "N-gram size",
+                type: "number",
+                value: 3
+            },
+            {
+                "name": "Join delimiter",
+                "type": "editableOptionShort",
+                "value": JOIN_DELIM_OPTIONS
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const nGramSize = args[0],
+            joinDelim = args[1];
+
+        const ngrams = [];
+        for (let i = 0; i <= input.length - nGramSize; i++) {
+            ngrams.push(input.slice(i, i + nGramSize));
+        }
+
+        return ngrams.join(joinDelim);
+    }
+
+}
+
+export default Ngram;