adding BraceMatching operation

src/core/config/Categories.json

@@ -230,7 +230,8 @@
             "Escape string",
             "Unescape string",
             "Pseudo-Random Number Generator",
-            "Sleep"
+            "Sleep",
+            "Brace Matching"
         ]
     },
     {

src/core/operations/Bracematching.mjs

@@ -0,0 +1,102 @@
+/**
+ * @author DBHeise [david@heiseink.com]
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+//import OperationError from "../errors/OperationError";
+
+/**
+ * Brace Matching operation
+ */
+class BraceMatching extends Operation {
+
+    /**
+     * BraceMatching constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Brace Matching";
+        this.module = "Default";
+        this.description = "Extracts nested grouping";
+        this.infoURL = "https://wikipedia.org/wiki/Brace_matching";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "Open Brace Character",
+                type: "string",
+                value: "("
+            },
+            {
+                name: "Close Brace Character",
+                type: "string",
+                value: ")"
+            },
+            {
+                name: "String Chars",
+                type: "string",
+                value: "\"'"
+            },
+            {
+                name: "Escape Char",
+                type: "string",
+                value: "\\"
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const [openChar, closeChar, strChars, escChar] = args;
+        let ans = "";
+        let isInString = false;
+        let nestLevel = 0;
+        let stringChar = null;
+        for (let i = 0; i < input.length; i++) {
+            const ch = input[i];
+            if (ch === openChar) {
+                if (!isInString) {
+                    nestLevel++;
+                    if (nestLevel === 1) {
+                        continue;
+                    }
+                }
+            } else if (ch === closeChar) {
+                if (!isInString) {
+                    nestLevel--;
+                    if (nestLevel < 1) {
+                        break;
+                    }
+                }
+            }
+            if (ch === escChar) {
+                ans += ch;
+                ans += input[i + 1];
+                i++;
+                continue;
+            } else if (stringChar && ch === stringChar) {
+                isInString = false;
+                stringChar = null;
+            } else if (strChars.indexOf(ch) > -1) {
+                if (!isInString) {
+                    isInString = true;
+                    stringChar = ch;
+                }
+            }
+            if (nestLevel > 0) {
+                ans += ch;
+            }
+        }
+        return ans;
+    }
+}
+
+export default BraceMatching;
+

tests/operations/index.mjs

@@ -90,6 +90,7 @@ import "./tests/Typex";
 import "./tests/BLAKE2b";
 import "./tests/BLAKE2s";
 import "./tests/Protobuf";
+import "./tests/BraceMatching";
 
 // Cannot test operations that use the File type yet
 //import "./tests/SplitColourChannels";

tests/operations/tests/BraceMatching.mjs

@@ -0,0 +1,101 @@
+/**
+ * Brace Matching tests.
+ *
+ * @author DBHeise [david@heiseink.com]
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import TestRegister from "../TestRegister";
+
+TestRegister.addTests([
+    {
+        name: "Brace Matching Simple",
+        input: "(test)",
+        expectedOutput: "test",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["(", ")", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Simple with extra text",
+        input: "this is a simple (test) of this function",
+        expectedOutput: "test",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["(", ")", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Simple with strings",
+        input: "{test \"}\"}",
+        expectedOutput: "test \"}\"",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["{", "}", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Simple with strings 2",
+        input: "{test '}'}",
+        expectedOutput: "test '}'",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["{", "}", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Simple nested",
+        input: "[this [test] good]",
+        expectedOutput: "this [test] good",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["[", "]", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Simple escaped",
+        input: "<test \\> foo bar>",
+        expectedOutput: "test \\> foo bar",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["<", ">", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Complex multi nesting 1",
+        input: "(((((test)))))(((((test)))))",
+        expectedOutput: "((((test))))",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["(", ")", "\"'", "\\"]
+            }
+        ]
+    },
+    {
+        name: "Brace Matching Complex multi nesting 2",
+        input: "(((((test))))(((((test))))))",
+        expectedOutput: "((((test))))(((((test)))))",
+        recipeConfig: [
+            {
+                "op": "Brace Matching",
+                "args": ["(", ")", "\"'", "\\"]
+            }
+        ]
+    }
+]);
+