> Oh, I see. I though it was meant to be used interchangeably. I can't use > string->blob, though, because that will copy the data and I need to modify > it from C. What foreign type should I use for this sort of thing? > > - (c-pointer char) with (location "string") works, but is a lot of typing > > - scheme-pointer seems to work, but: > > requires type cast in C: > > (print ((foreign-lambda* c-string ((scheme-pointer x)) "((char*)x)[0] = 65; > return(x);") "xBC")) > > allows all types, I just want blob/string: > > (print ((foreign-lambda* c-string ((scheme-pointer x)) "((char*)x)[0] = 65; > return(x);") 45.0)) > > is there a "string" foreign type that works like "blob", that provides a > (char*) argument and checks that argument is a string? Or is there a > string->blob/shared procedure anywhere?
You could also keep everything as it is and ignore the warning, but I understand that it isn't the cleanest solution. I'm not aware of any documented interchangability between strings and blobs, it is an implementation artefact. "string->blob/shared" would make sense but is not possible in the current implementation (srfi-4 vectors have an indirection to the raw data buffer, there this conversion only changes the wrapper object, but strings and blobs contain the data without the indirection.) So, I can't think of a solution that answers all of your questions. I would go with the scheme-pointer. We could add another foreign type, that accepts strings but doesn't copy. I'll look into that. felix _______________________________________________ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
