Easily Use Regular Expressions in Your Delphi Source Code

Delphi XE was the first release of Delphi to include support for regular expressions in the VCL. The RegularExpressionsCore unit contains the TPerlRegEx class, which is a wrapper around the PCRE library along with search-and-replace and split support. The RegularExpressions unit contains a set of records such as TRegex and TMatch that mimic the .NET classes such as Regex and Match.

If you are using Delphi 2010 or earlier to create Win32 applications, you will need to use a third party VCL component. RegexBuddy's Win32 Delphi source code snippets are based on the TPerlRegEx VCL component. This component is a wrapper around PCRE, with additional support for replace and split actions. The RegularExpressionsCore unit in Delphi XE is actually a slightly modified version of this component. You can download TPerlRegEx for free. TPerlRegEx Delphi source, PCRE C sources, PCRE OBJ files and DLL are included. You can choose to link the OBJ files directly into your application, or to use the DLL.

Microsoft's .NET framework provides a solid implementation of regular expressions. If you're using Delphi Prism (also known as Oxygene for .NET), or the Delphi for .NET compiler that CodeGear shipped with Delphi 8, 2005, 2006, and 2007, then simply add System.Text.RegularExpressions to the uses clause. You can then use all of the the regex classes from the .NET Common Language Runtime.

While .NET's regex support is solid, Microsoft's regex documentation is very poor. And it does not cover the Delphi language either. Fortunately, RegexBuddy makes it very easy to use the power of regexes in your Delphi Prism and Delphi for .NET source code.

See How Easy Coding with Regexes Can Be

First, use RegexBuddy to define a regex or retrieve a regexp saved in a RegexBuddy library. Rely on RegexBuddy's clear regex analysis, which is constantly updated as you build the pattern, rather than dealing with the cryptic regex syntax on your own. Detailed help on that syntax is always only a click away.

If you copied a regex written for another programming language, simply paste it into RegexBuddy, and select the original regex flavor. RegexBuddy will then automatically convert it to the .NET or PCRE regex flavor when you generate a Delphi Prism, Delphi for .NET, or Delphi for Win32 source code snippet.

If you created a new regular expression, test and debug it in RegexBuddy before using it in your Delphi source code. Test each regex in RegexBuddy's safe sandbox without risking precious data. Quickly apply the regex to a wide variety of input and sample data, without having to produce that input through your application.

Finally, let RegexBuddy generate a source code snippet that you can copy and paste directly into the RAD Studio IDE, or whichever Delphi code editor you use. Select "Delphi XE" as the language for code snippets that use the RegularExpressions unit in Delphi XE and later. Select "Delphi XE (Core) for Delphi XE's RegularExprssionsCore unit, or "Delphi (TPerlRegEx)" for the classic TPerlRegEx component for earlier Delphi versions, or "Delphi Prism" for Prism/Oxygene, or "Delphi (.NET)" for the discontinued Delphi for .NET compiler. Then choose what you want to use the regex for, and a fully functional code snippet is ready. You can change the names of variables and parameters to suit your naming style or the current situation, which RegexBuddy automatically remembers.

While the .NET Regex classes and the TPerlRegEx component are quite different, you don't have to remember the details of how to use either of them. Just tell RegexBuddy what you want to do, and you will get the proper Delphi Prism, Delphi for .NET, or Delphi for Win32 code straight away. Anything can be done: testing a string for a match, extracting search matches, validating input, search-and-replace, splitting a string, etc.