As to using JSON source. Yeah, it's a bit ugly, and you have to type more than with S-expressions. BUT: the typing overhead is constant, so I don't really worry about it. After all, the real typing savings come from the macros that are enabled by this syntax.
"I'm just lazy enough to wish that someone else had already done so :P"
Awkwardly, by the time I had a nice reader, I realized I didn't have any particular semantics in mind for the little language! So I decided to work on the semantics I really cared about instead. :-p Although this semantics is still incomplete, the reader is there whenever I'm ready for it. Maybe it could come in handy for Wat.
It's yet another read-table-based lisp reader. Every syntax, including lists, symbols, and whitespace, is a reader macro. My implementation of the symbol syntax is a bit nontraditional, because I also intend to use it for string literals.
I specifically designed it so it can run stand-alone, without any dependencies on the rest of Nulan. It takes a string and returns a JS array of strings, numbers, and Symbols. You can easily write a simple function to transform the output so that it's compatible with wat.
You're also free to modify it, though I'm not sure what license to use for Nulan. It'll probably be either the BSD/ISC license or Public Domain.