On Sun, Oct 6, 2013 at 3:42 AM, Luís Oliveira <lolive...@common-lisp.net> wrote: > On Sun, Oct 6, 2013 at 12:36 AM, Liam Healy <l...@healy.washington.dc.us> > wrote: >>> Having the foreign-string-alloc call lisp-string-to-foreign would >>> cause the string length to be calculated twice. But it indeed seems >>> like they could both share a helper function at least. >> >> Are you sure? >> >> ;;; LMH new function >> (defun length-of-string-as-foreign (string encoding start end >> null-terminated-p) >> (+ (funcall (octet-counter (lookup-mapping *foreign-string-mappings* >> encoding)) > [...] > >> ;;; LMH new version >> (defun foreign-string-alloc (string &key (encoding >> *default-foreign-encoding*) >> (null-terminated-p t) (start 0) end) > [...] >> (lisp-string-to-foreign >> string ptr length :start start :end end :encoding encoding) > [...] > > >> The only duplication of effort is mapping and null-len, which seem >> like pretty lightweight operations. > > This version of foreign-string-alloc calls the octet-counter function > twice. Once via length-of-string-as-foreign then again via > lisp-string-to-foreign. > > Cheers, > > -- > Luís Oliveira > http://kerno.org/~luis/
Is that important? octect-counter is a slot lookup. I've always considered slots the equivalent of ordinary variables, so this seems at least as efficient as the alternatives. Liam
