Ur/Web: tests/impl.ur annotate

Polymorphic variants

author	Adam Chlipala <adam@chlipala.net>
date	Thu, 19 Aug 2010 17:28:52 -0400
parents	8d3aa6c7cee0
children

rev	line source
adamc@1093	1 fun id [t :: Type] (x : t) = x
adamc@15	2 val id_self = id [t :: Type -> t -> t] id
adamc@15	3
adamc@1093	4 fun idi [t ::: Type] (x : t) = x
adamc@1093	5 val idi_self = idi @@idi
adamc@17	6
adamc@1093	7 fun picker [na :: Name] [a ::: Type] [nb :: Name] [b ::: Type] [fs ::: {Type}] [[na] ~ [nb]] [[na, nb] ~ fs]
adamc@1093	8 (r : $([na = a, nb = b] ++ fs)) = {na = r.na, nb = r.nb}
adamc@17	9 val getem = picker [#A] [#C] {A = 0, B = 1.0, C = "hi", D = {}}
adamc@18	10 val getem2 = picker [#A] [_] {A = 0, B = 1.0, C = "hi", D = {}}
adamc@18	11 val getem3 = picker [#A] [_::Name] {A = 0, B = 1.0, C = "hi", D = {}}
adamc@17	12
adamc@1093	13 fun picker_ohmy [na ::: Name] [a ::: Type] [nb ::: Name] [b ::: Type] [fs ::: {Type}] [[na] ~ [nb]] [[na, nb] ~ fs]
adamc@1093	14 (r : $([na = a, nb = b] ++ fs)) = {na = r.na, nb = r.nb}
adamc@17	15 val getem_ohmy = picker_ohmy {A = 0, B = 1.0, C = "hi", D = {}}
adamc@1093	16
adamc@1093	17 fun proj [fs] [t] [nm :: Name] [[nm] ~ fs] (r : $([nm = t] ++ fs)) = r.nm
adamc@1093	18 val one = proj [#A] {A = 1, B = True}

Mercurial > urweb