What flavor of Regex does Visual Studio Code use?

Eric picture Eric · Feb 11, 2017 · Viewed 87.4k times · Source

Trying to search-replace in Visual Studio Code, I find that its Regex flavor is different from full Visual Studio. Specifically, I try to declare a named group with string (?<p>[\w]+) which works in Visual Studio but not in Visual Studio Code. It'll complain with the error Invalid group.

Apart from solving this specific issue, I'm looking for information about the flavor of Regexes in Visual Studio Code and where to find documentation about it, so I can help myself with any other questions I might stumble upon.

Full Visual Studio uses .NET Regular Expressions as documented here. This link is mentioned as the documentation for VS Code elsewhere on Stackoverflow, but it's not.

Answer

Shaun Luttin picture Shaun Luttin · Feb 12, 2017

Rust Regex in the Find/Replace in Files Sidebar

Rob Lourens of MSFT wrote that the file search uses Rust regex. The Rust language documentation describes the syntax.

Rob Lourens on GitHub

JavaScript Regex in the Find/Replace in File Widget

Alexandru Dima of MSFT wrote that the find widget uses JavaScript regex. As Wicktor commented, ECMAScript 5's documentation describes the syntax. So does the MDN JavaScript Regular Expression Guide.

Alexandru Dima on GitHub

Test the Difference

The find in files sidebar does not support (?=foobar) whereas the find in file widget does support that lookahead syntax.

Shows a lookahead working in the widget but not in the sidebar.

Regarding Find/Replace with Groups

To find/replace with groups, use parentheses () to group and $1, $2, $3, $n to replace.

Here is an example.

Before:

This is the text before the replace.

After:

This is the text after the replace.