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comparison lib/basis.urs @ 564:803b2f3bb86b

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Monad type class seems to be working
author Adam Chlipala <adamc@hcoop.net>
date Fri, 19 Dec 2008 10:27:58 -0500
parents 5d494183ca89
children 74800be65591
comparison
equal deleted inserted replaced
563:44958d74c43f 564:803b2f3bb86b
67 val read_string : read string 67 val read_string : read string
68 val read_bool : read bool 68 val read_bool : read bool
69 val read_time : read time 69 val read_time : read time
70 70
71 71
72 (** * Transactions *) 72 (** * Monads *)
73
74 class monad :: Type -> Type
75 val return : m ::: (Type -> Type) -> t ::: Type
76 -> monad m
77 -> t -> m t
78 val bind : m ::: (Type -> Type) -> t1 ::: Type -> t2 ::: Type
79 -> monad m
80 -> m t1 -> (t1 -> m t2)
81 -> m t2
82
83 (** ** Transactions *)
73 84
74 con transaction :: Type -> Type 85 con transaction :: Type -> Type
75 86 val transaction_monad : monad transaction
76 val return : t ::: Type 87
77 -> t -> transaction t
78 val bind : t1 ::: Type -> t2 ::: Type
79 -> transaction t1 -> (t1 -> transaction t2)
80 -> transaction t2
81 88
82 89
83 (** HTTP operations *) 90 (** HTTP operations *)
84 91
85 val requestHeader : string -> transaction (option string) 92 val requestHeader : string -> transaction (option string)