Add comparing to a formula string

sfdx-source/apex-extensions/main/default/classes/utils/fflib_StringUtils.cls

@@ -0,0 +1,47 @@
+/**
+ * File Name: fflib_StringUtils
+ *
+ * @author : architect ir. Wilhelmus G.J. Velzeboer
+ */
+public with sharing class fflib_StringUtils
+{
+	public static String getBetweenBrackets(String open, String close, String expression, Integer index)
+	{
+		Integer openChar = open.charAt(0);
+		Integer closeChar = close.charAt(0);
+
+		// If index given is invalid and is
+		// not an opening bracket.
+		if (expression.charAt(index) != openChar)
+			new StringException('Expected char \'' + open + '\' as position ' + index);
+
+		// Stack to store opening brackets.
+		List<Integer> stack = new List<Integer>();
+
+		// Traverse through string starting from
+		// given index.
+		for (Integer i = index; i < expression.length(); i++)
+		{
+
+			// If current character is an opening bracket push it in stack.
+			if (expression.charAt(i) == openChar)
+			{
+				stack.add(expression.charAt(i));
+			}
+			// If current character is a closing bracket, pop from stack.
+			// If stack is empty, then this closing bracket is required bracket.
+			else if (expression.charAt(i) == closeChar)
+			{
+				stack.remove(stack.size()-1);
+				if (stack.isEmpty())
+				{
+					return expression.substring(index + 1, i);
+				}
+			}
+		}
+
+		return null;
+	}
+
+	public class StringException extends Exception {}
+}

sfdx-source/apex-extensions/main/default/classes/utils/fflib_StringUtils.cls-meta.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
+    <apiVersion>51.0</apiVersion>
+    <status>Active</status>
+</ApexClass>