(More of a demo than a real proposal.)
arc> (sequence->list "foo")
'(#\f #\o #\o)
arc> (sequence->list (in-range 10 0 -0.5))
'(10
9.5
9.0
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5)
arc> (each n (in-range 10 0 -0.5) (out n (expt n 2)))
'((10 100)
(9.5 90.25)
(9.0 81.0)
(8.5 72.25)
(8.0 64.0)
(7.5 56.25)
(7.0 49.0)
(6.5 42.25)
(6.0 36.0)
(5.5 30.25)
(5.0 25.0)
(4.5 20.25)
(4.0 16.0)
(3.5 12.25)
(3.0 9.0)
(2.5 6.25)
(2.0 4.0)
(1.5 2.25)
(1.0 1.0)
(0.5 0.25))
; use racket's sort
arc> (|sort| '(a b "foo" 21) (compare > string))
'("foo" b a 21)
arc> (|sort| '(a b "foo" 21) (compare < string))
'(21 a b "foo")
arc> (sequence->list (in-producer (thunk (bytes-ref (crypto-random-bytes 1) 0)) (%do [< _ 42])))
'(56 119)
arc> (sequence->list (in-producer (thunk (bytes-ref (crypto-random-bytes 1) 0)) (%do [< _ 42])))
'(192 163 45 163 79 184 218 105 67 67 240 228)
arc> (sequence->list (in-producer (thunk (bytes-ref (crypto-random-bytes 1) 0)) (%do [< _ 42])))
'(189)
arc> (sequence->list (in-producer (thunk (bytes-ref (crypto-random-bytes 1) 0)) (%do [< _ 42])))
'(141 148 243)
arc> (define (1+ (n 0)) (+ n 1))
arc> (1+ 21)
22
arc> (1+)
1
arc> (1+:1+:1+ 21)
24If an expression starts with a symbol bound to a racket syntax transformer, then the arc compiler switches to "racket-style" output.
(begin "everything in here is racket code...")
arc> (begin (require racket) (%do (+ "foo" 42)))
"foo42"
It's pretty convenient to call any racket function without worrying about interop.
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> If you want to switch back to arc, you can use (%do ...)
Personally I would prefer '.arc' or '%arc':
arc> (begin (require racket) (.arc (+ "foo" 42)))
"foo42"
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.arc / .racket (or .rkt) seems more intuitive than .arc / $
We could also keep the dollar sign in both cases, which I prefer aesthetically, because being familiar with javascript and C type languages, seeing a dot alone like that just seems weird.
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Basically, I think it's a bad idea to change `ac` into something which sometimes compiles Arc code and sometimes does something more like code-walking over s-expressions. I think Anarki's existing "$ ... unquote" syntax already serves this purpose and uses the same kind of code-walking but does so with a better separation of concerns.
Moreover, the way you're taking out the |foo| syntax so you can redefine it to be a variant of $ seems like a net loss.
(Some of my other comments on that review are less fundamental objections: Style nitpicks, observations of bugs, or wild ideas that I don't really expect anyone to act on in the short term.)
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