[rattray]

I'm currently thinking through the design of a pattern-matching feature for JavaScript, through a superset I'm building called LightScript[0].

I liked that this article laid out the specific options and various shades of gray that can constitute parts of "pattern matching".

I'm curious for thoughts on a syntax like this:

    x = match y:
      case > 3: () => "it's bigger than three"
      case 2: () => "it's strictly equal to two"
      case Integer: (x) => `some int smaller than two: ${x}`
      case String: (s) => `some string: ${s}`
      case Array: ([ first, ...rest ]) => `a list starting with ${first}`
      case Object: ({ a, b }) => `an object with property a: ${a}`
      

This is somewhat more difficult given that even when using Flow or TypeScript, there's relatively little type granularity available at runtime.

Any thoughts?

[0] http://lightscript.org