Design: WAT syntax as a valid JavaScript subset

[thysultan]

To permit comma separated S-expressions within the text format to allow the WAT syntax to be a valid parse-time JavaScript subset syntax like JSON is to JavaScript.

This would allow you to write the following example:

(func $swap (param i32 i32) (result i32 i32) (get_local 1) (get_local 0))

As the following:

(func, $swap, (param, i32, i32), (result, i32, i32), (get_local, 1) (get_local, 0))

One application of this is being able to write valid WAT syntax in JavaScript functions

function add (a, b) {
   (i32.const, a)
   (i32.const, b)
   (i32.const, add)
}

That you can add.toString() to extract valid WAT source code, that can make it easier to interleave WAT source code within JavaScript without the need for template literals when prototyping.

[KronicDeth]

S-expressions make me think of Lisp and because of that I would expect ' to mean quote and , to mean unquote.

[binji]

This is an interesting idea, but I'm not sure we'll want to modify the text format to support it.

[xtuc]

I'm really not sure we want to have JS-compatible WAST. Mostly because from a parser perpective it would be really hard to tell if you are writing WAST or JS.

I would rather use JS's template literals:

function add (a, b) {
   wast`
     (i32.const, a)
     (i32.const, b)
     (i32.const, add)
   `
}

[carlsmith]

You could knock up a WAT DSL in CoffeeScript very easily. Just to offer another option.