Bug: Template and Tail-call Optimization
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#include "share/atspre_staload.hats"
extern fun {a:t@ype} show (a): void
implement {a} show (x) = gprint_val<a> x
datatype maybe (a:t@ype) =
| Nothing (a) of ()
| Just (a) of a
implement (a) show<maybe a> (m) =
case+ m of
// | Nothing () => gprint_val<string> "Nothing"
| Nothing () => ignoret (show<string> "Nothing")
// | Just x => gprint_val<a> x
| Just x => ignoret (show<a> x)
// this is a bug due to tail-call optimization
// use ignoret, or use patscc --tlcalopt-disable
extern fun {a:t@ype} cmp (a, a): int
implement {a} cmp (x, y) = gcompare_val_val<a> (x, y)
implement (a) cmp<maybe a> (x, y) =
case+ (x, y) of
| (Nothing _, Nothing _) => 0
| (Nothing _, Just _) => ~1
| (Just _, Nothing _) => 1
| (Just x, Just y) => cmp<a> (x, y)
implement main0 () = {
val _ = show<maybe int> (Nothing{int} ())
val _ = show<maybe char> (Just ('a'))
val _ = cmp<maybe int> (Just 3, Just 5)
}
Ats
INFO