ESM: Ported StrUtils and NetBIOS operations.

src/core/operations/Head.mjs

@@ -0,0 +1,68 @@
+/**
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import Utils from "../Utils";
+import {INPUT_DELIM_OPTIONS} from "../lib/Delim";
+
+/**
+ * Head operation
+ */
+class Head extends Operation {
+
+    /**
+     * Head constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Head";
+        this.module = "Default";
+        this.description = "Like the UNIX head utility.<br>Gets the first n lines.<br>You can select all but the last n lines by entering a negative value for n.<br>The delimiter can be changed so that instead of lines, fields (i.e. commas) are selected instead.";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                "name": "Delimiter",
+                "type": "option",
+                "value": INPUT_DELIM_OPTIONS
+            },
+            {
+                "name": "Number",
+                "type": "number",
+                "value": 10
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        let delimiter = args[0];
+        const number = args[1];
+
+        delimiter = Utils.charRep(delimiter);
+        const splitInput = input.split(delimiter);
+
+        return splitInput
+            .filter((line, lineIndex) => {
+                lineIndex += 1;
+
+                if (number < 0) {
+                    return lineIndex <= splitInput.length + number;
+                } else {
+                    return lineIndex <= number;
+                }
+            })
+            .join(delimiter);
+    }
+
+}
+
+export default Head;