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fn-pattern code in but not tested yet; hello compiles
author Adam Chlipala <adamc@hcoop.net>
date Thu, 28 May 2009 10:16:50 -0400
parents 395a5d450cc0
children 78504d97410b
comparison
equal deleted inserted replaced
821:395a5d450cc0 822:d4e811beb8eb
81 [] => rev acc 81 [] => rev acc
82 | x :: ls => fil (if f x then x :: acc else acc) ls 82 | x :: ls => fil (if f x then x :: acc else acc) ls
83 in 83 in
84 fil [] 84 fil []
85 end 85 end
86
87 fun exists (a ::: Type) f =
88 let
89 fun ex ls =
90 case ls of
91 [] => False
92 | x :: ls =>
93 if f x then
94 True
95 else
96 ex ls
97 in
98 ex
99 end
100
101 fun foldlMap (a ::: Type) (b ::: Type) (c ::: Type) f =
102 let
103 fun fold ls' st ls =
104 case ls of
105 [] => (rev ls', st)
106 | x :: ls =>
107 case f x st of
108 (y, st) => fold (y :: ls') st ls
109 in
110 fold []
111 end