[Openmcl-devel] NSStrings

Paul D. Lathrop plathrop at nmu.edu
Wed Mar 3 05:57:30 PST 2004

I am doing some work with the cocoa/objc bridge (for the Clotho 
project) and I've come across some confusion involving passing a string 
from the lisp to the objc runtime. What I am working on currently is 
implementing a function that will swap the case of the current 
selection. I am able to get the selection and change it's case. I am 
then allocating an nsstring using the following form:

(ccl::%make-nsstring new-string)

new-string is the lispy form of the string I'm trying to send. The 
problem is, when the string reaches the cocoa component I'm sending it 
to, it has one character's worth of garbage appended to it. The lisp 
doesn't see this garbage at all - it registers the nsstring as:

#<NS-CONSTANT-STRING "FOObarBAz" (#x155190)>

whereas, Cocoa gives me:


(note the extra char on the end). Am I missing a "proper" way of 
accomplishing this? If not, what am I missing? The only clue I have 
left is that the string I get *from* the objc runtime is:

#<NS-CF-STRING "fooBARbaZ" (#x160B50)>

Which is not what I am sending back. Could this be a problem? If it is, 
how do I allocate the appropriate type of string? If I'm missing 
something obvious, feel free to RTFM me.

Paul Lathrop

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