3 ms·

I don't think so? Judging by the documentation that's just the usual option (also available in CL) to have struct fields stored in an array, list, name value pa

by foldr 4y ago

I don't think so? Judging by the documentation that's just the usual option (also available in CL) to have struct fields stored in an array, list, name value pair list, etc. There's no suggestion that it would accomplish unboxing in general. I guess it is possible that if each field of the struct had the same type (say, a float), then the backing storage for the struct would be an unboxed array of floats, and an array of such structs would then come out with its backing storage as an unboxed multidimensional array of floats. But: * I'd really want to see this actually working to believe it. The documentation doesn't make clear what would happen in this circumstance. (Time to spin up OpenGenera? Ha!) * At best this works for structures with homogenous field types. My example of a 2D vector happens to fit that criterion, but it is also useful to have unboxed arrays of structures with heterogenous field types. http://www.bitsavers.org/pdf/symbolics/software/genera_8/Symbolics_Common_Lisp_Programming_Constructs.pdf http://www.bitsavers.org/pdf/symbolics/software/genera_8/Sym... (page 450 according to the on-page numbering).

pjmlp 4y ago
Accessors take care of reading/writing from the backing storage mechanism. If you want to be really picky, don't forget the whole OS was written in Lisp, and even the C, Pascal and Ada compilers targeted it, and much follow the same semantics. The same folder has the manuals for C and Pascal. And if you want to be really sure how it goes, there is the low level forms for Assembly like coding, e.g. sys:art-q, which is used to pack C structures into arrays.
- foldr 4y ago
  (:type :array) is documented as the default. So there must be something more required to create an unboxed array of structs than just that. If, for whatever reason, it is important to you to persuade the internet that the Lisp dialect of a long-defunct operating system was able to define unboxed arrays of structs, then I think you should at least show example code demonstrating this. The more salient point, however, is that Common Lisp can't do this.

by foldr 4y ago

pjmlp 4y ago

Accessors take care of reading/writing from the backing storage mechanism. If you want to be really picky, don't forget the whole OS was written in Lisp, and even the C, Pascal and Ada compilers targeted it, and much follow the same semantics. The same folder has the manuals for C and Pascal. And if you want to be really sure how it goes, there is the low level forms for Assembly like coding, e.g. sys:art-q, which is used to pack C structures into arrays.

foldr 4y ago
(:type :array) is documented as the default. So there must be something more required to create an unboxed array of structs than just that. If, for whatever reason, it is important to you to persuade the internet that the Lisp dialect of a long-defunct operating system was able to define unboxed arrays of structs, then I think you should at least show example code demonstrating this. The more salient point, however, is that Common Lisp can't do this.