Beispiel Typed

Jan Burse, erstellt 23. Aug 2016
/**
* Prolog code for the type inference
* without subject to occurs check.
*
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* regarding the provided information. XLOG Technologies GmbH assumes
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* provided by XLOG Technologies GmbH.
*
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* and patent rights in particular - are the sole property of XLOG
* Technologies GmbH. If the company was not the originator of some
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*
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* of the information is only allowed for non-commercial uses. Selling,
* giving away or letting of the execution of the library is prohibited.
* The library can be distributed as part of your applications and libraries
* for execution provided this comment remains unchanged.
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* Jekejeke is a registered trademark of XLOG Technologies GmbH.
*/
:- use_module(library(experiment/maps)).
/*******************************************************/
/* Type Inference for Simple Types */
/*******************************************************/
% typed(+Expression, +Context, -Type)
typed(X, C, T) :-
var(X), !,
get(C, X, T).
typed(lam(X,E), C, (S->T)) :-
typed(E, [X-S|C], T).
typed(app(E,F), C, T) :-
typed(E, C, (S->T)),
typed(F, C, S).
% ?- typed(app(E,F), [E-A,F-B], C).
% A = (B->C)
% ?- typed(app(F,F), [F-A], B).
% A = (A->B) or crash, both undesired
% ?- typed(lam(X,lam(Y,app(Y,X))), [], A).
% A = (_C->(_C->_I)->_I)

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