+# API Notation Updates
+
+A few years ago I created an API notation to use with software specification documents: Back then I was working in a team that relied heavily on software specifications, and we were maintaining projects in objective-c, ruby, and javascript, so the notation emerged out of the need to communicate the public APIs in a way that was generic enough to make implementation in any language simple, while concise enough to avoid integration issues.
+
+For example, I could use it to describe the library I use to build this blog[1]
+
+```
+// Library to generate an ephemeral html blog with a gemini archive
+Blog
+ -max_posts <Int>
+ -posts_directory <String>
+ -archive_directory <String>
+ -static_directory <String>
+ -templates_directory <String>
+ -remote_config <String>
+ #add(post_location <String>) => Promise<Void>
+ #update(post_location <String>) => Promise<Void>
+ #publish(host <String>) => Promise<Void>
+ #publish_archive(host <String>) => Promise<Void>
+ #add_remote(remote <String>) => Promise<Void>
+ #remove_remote() => Promise<Void>
+ #sync_down() => Promise<Void>
+ #sync_up() => Promise<Void>
+ #generate() => Promise<Void>
+```
+
+=> https://git.sr.ht/~rbdr/blog/tree/main/item/lib/blog.js [1] A Javascript implementation of that API
+
+I had been using it unchanged for almost ten years, but recently decided to drop a specific symbol for callbacks, and instead add a "Throws" symbol #>. You can see the definition here, or in its home page[2]
+
+```
+// Anything after two forward slashes is a comment
+NameOfClass.WithPossibleNamespace
+ + class property
+ - instance property
+ ~> listened events (socket)
+ +> listened events (class/module)
+ -> listened events (instance)
+ <~ dispatched events (socket)
+ <+ dispatched events(class/module)
+ <- dispatched events (instance)
+ :: class method
+ # instance method
+
+Other symbols
+ => returns
+ #> throws
+[xx] optional
+<data type>
+
+Recommended order: class first, then sockets, then instance. Internally:
+Properties, events, methods.
+```
+
+One of the patterns that I started using for functions is to instead define the whole function signature as part of the type definition. So for example, if you have a method that receives a function as an argument, you could write the following:
+
+```
+GenericManipulator
+ #manipulate<T>(input T, manipulator<T>(input T, options <ManipulationOptions>) => T #> ManipulationError) => T #> ManipulationError
+```
+
+I've found this pattern covers most cases where I need to pass a function.
+
+In slightly related news, since I've recently moved fully to using `neovim`, I've also created a tree-sitter parser[3] that you can use as a neovim plugin. It was really fun to learn, but the documentations was clear and easy to follow. A bit less easy to follow was how to get the syntax highlighting to actually work with neovim, but it ended up working.
+
+=> https://www.unlimited.pizza/api.html [2] API definition
+=> https://git.sr.ht/~rbdr/tree-sitter-api-notation [3] tree-sitter parser and neovim plugin.
+
+If you use other editors, there's older versions of the plugin available for vim[4], vscode[5], and TextMate / Sublime Text[6]. They don't support the #> throws notation.
+
+=> https://git.sr.ht/~rbdr/api-notation.vim [4] Syntax for vim
+=> https://git.sr.ht/~rbdr/api-notation.vscode [5] Syntax for vscode
+=> https://git.sr.ht/~rbdr/api-notation.tmLanguage [6] Syntax for TextMate and Sublime text
git.r.bdr.sh / rbdr / blog.unlimited.pizza / commitdiff