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A convenience macro for direct calls to foreign functions.
Note: this extension is only needed for CHICKEN versions 2.425 and higher
<macro>($ [RETURNTYPE] NAME (TYPE ARGUMENT) ...)<macro>
Invokes a C/C++ function by evaluating the arguments, performing the neccessary type-conversions for the foreign type-specifiers TYPE ... and calling NAME (which must be a symbol).
If RETURNTYPE is given, then the result will be converted properly and returned, otherwise void is assumed.
The type/argument lists may also be literal Scheme data or expressions of the form (quote LITERAL) or (location ...) - in this case the arguments are converted according to the type of the literal or are treated as a c-pointer, respectively.
Booleans, characters, numbers, strings, SRFI-4 number vectors and symbols are converted, all other data is passed as being of type scheme-object.
Callbacks into Scheme are not allowed inside the invoked foreign code.
This macro expands into one of the foreign-lambda*, foreign-code or foreign-value forms.
(require-library dollar) (import dollar)
csc ... -extend dollar ...
($ printf "%d times Hello, %s!\n" 1000 "world") (define f 99.2) (let-location ((double n)) (let ((f ($ double modf (double f) (location n)))) (cons n f) ) )
Bugs and Limitations
- 'csc ... -extend dollar ...' does not work as expected.
- minor documentation fixes.
- Chicken 4 release.
Copyright (c) 2000-2006, Felix L. Winkelmann All rights reserved.
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