The C# code from C# ‘pragma foreign_proc’ declarations
will be placed in the bodies of static member functions
of an automatically generated C# class.
Since such C# code will become part of a static member function,
it must not refer to the
It may however refer to static member variables or static member functions
declared with ‘pragma foreign_code’.
The input and output variables for a C# ‘pragma foreign_proc’ will have C# types corresponding to their Mercury types. The exact rules for mapping Mercury types to C# types are described in C# data passing conventions.
C# code in a
pragma foreign_proc declaration
for any procedure whose determinism indicates that it can fail
must assign a value of type
to the variable
:- pred string.contains_char(string, character). :- mode string.contains_char(in, in) is semidet. :- pragma foreign_proc("C#", string.contains_char(Str::in, Ch::in), [will_not_call_mercury, promise_pure], " SUCCESS_INDICATOR = (Str.IndexOf(Ch) != -1); ").
C# code for procedures whose determinism indicates that they cannot fail
should not access
Arguments whose mode is input
will have their values set by the Mercury implementation
on entry to the C# code.
If the procedure succeeds,
the C# code must set the values of all output arguments.
If the procedure fails,
the C# code need only set
SUCCESS_INDICATOR to false.