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Reference to polymorphic function ?
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| Date: | -- (:) |
| From: | Ingo Bormuth <ibormuth@e...> |
| Subject: | Reference to polymorphic function ? |
Hi list,
the following declaration of put_to_screen nicely accepts all kinds
of values as v. This is the expected behaviour.
# let put_to_screen v = print_string ( Marshal.to_string v [] ) ;;
val put_to_screen : 'a -> unit = <fun>
# put_to_screen "test" ;;
%%%%%test- : unit = ()
# put_to_screen 5 ;;
%%%%%E- : unit = ()
Nevertheless, if I store the polymorphic function in a reference to
create a closure for all kinds of output methodeis, any attemps to use
that function are thwarted by the type interferer.
# let put = ref put_to_screen ;;
val put : ('_a -> unit) ref = {contents = <fun>}
# !put "test" ;;
%%%%%%test- : unit = ()
# !put 5 ;;
This expression has type int but is here used with type string
How can I keep the interferer from explicitly resolving the type of v ?
# put;;
- : (string -> unit) ref = {contents = <fun>}
Thanks !
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