Open on Github

note: if you want to use an extension that is quite a bit more complete, you should check out Stitch by bscotch.

A simple extension that should support any versions including and above the 2022.0 (LTS) version of GameMaker Studio 2. It aims to support the latest stable versions of gamemaker as they come out.
(This extension uses a fair amount of the source code from an old(ish) extension created by LiarOnce under the MIT License)

What this extension will do:

• autocompletion, hover, and highlighting of important tokens, such as local variables, macros, built-in functions, etc.
• provide goto definition references for constants (namely script functions and macros)
• provide colors for color literals, color_make_* functions, and macros
• allow maximum customizability
  • you are able to toggle nearly every feature of the extension via user/workspace settings

What this extension will not do:

• provide autocompletion/intellisense for the contents of the global struct
• provide autocompletion/intellisense for instance variables (due to the many nuances with using them)
• know what the context of self is at any given moment, especially for in global functions
  (however, this may be possible in object events, we shall see)

Capabilities I plan on adding in the future:

• an easier way to implement all of the built-in functions and constants
• infer the types of variables to provide info in things like hover, completions, etc.
• move more of the responsibilities from the client to the language server