Racket "wat"s

inspired by Gary Bernhardt's original "Wat" talk

This repository is an ongoing work in progress, and is intended to be a community effort. If you have anything new wat's to contribute, or think one should be removed, please create a pull request!

List of wat's

• Numbers are mutable

Welcome to Racket v7.5.0.900.
> (immutable? 5)
#f

• Unquote can be weird:

Welcome to Racket v7.5.0.900.
> `(4 . ,(+ 1 2))
(4 . 3)
> '(4 . ,(+ 1 2))
'(4 unquote (+ 1 2))

• Argument order for collections:

Welcome to Racket v7.5.0.900.
> (member 'x (list 'x 'y))
#t
> (vector-member 'x (vector 'x 'y))
#t
> (set-member? (set 'x 'y) 'x)
#t

• gensym is special

Welcome to Racket v7.5.0.900.
> (define x (gensym))
> x
'g78
> (eq? x 'g78)
#f

• hash-map doesn't return a hash

Welcome to Racket v7.5.0.900.
> (map list '(1 2 3))
'((1) (2) (3))
> (vector-map list #(1 2 3))
'#((1) (2) (3))
> (hash-map (hash 'x 1 'y 2) list)
'((x 1) (y 2))  ; that's not a hash map...

• append semantics

append with an empty list as the first argument just returns the second argument, regardless of what it is

Welcome to Racket v7.5.0.900.
> (append '(1 2) '#(1 2))
'(1 2 . #(1 2))
> (append '() '#(1 2))
'#(1 2)
> (append (list) '#(1 2))
'#(1 2)

• specials

why use async channels when u can

> (define-values [in out] (make-pipe-with-specials))
> (write-special + out)
#t
> (read-char-or-special in)
#<procedure:+>

• the top level is hopeless

> (define (map) map)
> (eq? (map) map)
#f
> (define (map) map)
> (eq? (map) map)
#t

> (define (map) (#%top . map))
> (eq? (map) map)
#t

• TODO more