I only just downloaded and tried out Jarc 16 (which you don't have a thread for, but you mentioned at http://arclanguage.org/item?id=11915), and I noticed this:
Jarc> (do:compose idfn idfn)
(stdin):1: Error: Type-error:
compose is not of type LIST
I was using do:compose in some generated code as a way to force the macro meaning of 'compose, as opposed to the special meaning (compose ...) has in functional position.
There's an easy workaround--(do (compose ...))--and there's an easy fix too. In Jarc's utils.arc, 'expand-metafn is slightly different from arc.arc's 'expand-metafn-call: Instead of checking the caar of the remaining arguments with (iscar (car fs) 'compose), it checks the car with (is (safecar fs) 'compose). So it doesn't actually splice together nested 'compose calls; it just sometimes causes an error taking the cdr of the symbol 'compose. :)
As long as I'm looking at the source for 'expand-metafn, the if clause for 'andf seems a bit off:
I think you mean (is (car f) 'andf) there. ^_^ Also, that implementation of 'andf evaluates the outer arguments a variable number of times. The Arc 3.1 version--I haven't looked at others--evaluates them exactly once by expanding like this instead:
((andf a b) c d)
=>
((fn (gs1 gs2) (and (a gs1 gs2) (b gs1 gs2))) c d)
Furthermore, the parameters of 'if (and 'and, by extension) should be macro-expanded when the (if ...) form is compiled, but Jarc doesn't do this.
Whew! Here's a transcript highlighting some of those differences:
Jarc 16:
Jarc> (mac foo args (prn "expanding foo with " args) `',args)
#3(tagged mac #<procedure>)
Jarc> (and (foo) (foo "true"))
expanding foo with nil
nil
Jarc> (if (foo) (foo "true"))
expanding foo with nil
nil
Jarc> (foo&foo)
expanding foo with nil
nil
Jarc> (foo&foo "true")
expanding foo with ("true")
expanding foo with ("true")
("true")
Jarc> (foo&foo (do prn!evaluating "true"))
expanding foo with ((do prn!evaluating "true"))
expanding foo with ((do prn!evaluating "true"))
((do prn!evaluating "true"))
Jarc> (idfn&idfn (do prn!evaluating "true"))
evaluating
evaluating
"true"
Arc 3.1 (but your gensyms may vary; I load Lathe in my libs.arc):
Use (quit) to quit, (tl) to return here after an interrupt.
arc> (mac foo args (prn "expanding foo with " args) `',args)
#(tagged mac #<procedure: foo>)
arc> (and (foo) (foo "true"))
expanding foo with ()
expanding foo with (true)
nil
Jarc> (if (foo) (foo "true"))
expanding foo with ()
expanding foo with (true)
nil
arc> (foo&foo)
expanding foo with ()
expanding foo with ()
nil
arc> (foo&foo "true")
expanding foo with (gs1999)
expanding foo with (gs1999)
(gs1999)
arc> (foo&foo (do prn!evaluating "true"))
expanding foo with (gs2000)
expanding foo with (gs2000)
evaluating
(gs2000)
arc> (idfn&idfn (do prn!evaluating "true"))
evaluating
"true"
