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Re: non-local exits are icky

This page is part of the web mail archives of SRFI 50 from before July 7th, 2015. The new archives for SRFI 50 contain all messages, not just those from before July 7th, 2015.

>>>>> "Tom" == Tom Lord <lord@xxxxxxx> writes:

Tom> An FFI should be able to handle a situation where:

Tom> 	Scheme calls out to C, eventually to handle_event.

Tom>         handle_event calls to C, to my_hook_fn.

Tom>         my_hook_fn calls out to Scheme

Tom> Unless the GUI library I'm using has made it safe to longjmp past
Tom> handle_event, I can not implement this using the proposed FFI.  A
Tom> Scheme error underneat my_hook_fn will want to exit all the way past
Tom> handle_event.

This all hinges on your definition of "Scheme error."  The errors
signalled by the primitives in SRFI 50 all mean that there's a *bug*
in your program.  I'll admit that being able to "handle" this kind of
situation would be useful, but I don't even know what the right way to
do this would be in *Scheme*, much less in C.

Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla