I need to create an array representing a series of string tuples, padding with a null between them. In c, it would be something like:
tuples[1] = "bar";
tuples[2] = NULL;
I tried the following in newlisp:
That did not, apparently, work... anyone know better than I?
actually is does work (if this is what you want?):
> (setf packed (pack "s4 s4 s1" "foo" "bar" ""))
"foo 00bar 00 00"
>
but you could have that easier:
(setq packed "foox00barx00x00") ; or 2 digit hex
are you sure you don't want an array of string pointers, like char * data[] or char ** data (same)? Your: tuples[0] = "foo" ... example suggests, that it is what you want:
the third pointer in the array would be a NULL pointer, as usual in this kind of C array.
ps: look also here: http://www.newlisp.org/CodePatterns.html#extending
last row in both tables at the end of the chapter
... forgot to mention:
make sure that your strings in newLISP are anchored to a fixed location, i.e:
(set 'packed (pack "lu lu lu" str-array))
I thought that "lu lu lu" would coerce the strings into integers. The case I am working toward is a function that requires parameters to be passed as an array of tuples (string * string), terminated with a NULL. The documentation is here:
http://xmlsoft.org/xslt/html/libxslt-transform.html#xsltApplyStylesheet
I am trying to pass the params argument and construct it from an arbitrary association list.
those integers in:
will be taken as string pointers in the receiving function. The receiving function will take each of the three integers as a pointer to a string and check for NULL. When it hits the third, it knows that the end of the array is reached.
void showStrings(char * * params)
{
while(*params != NULL)
printf("->%sn", *params++);
}
compile on Mac OS X (on Linux use -shared instead of -bundle and -o test.so):
and import and use:
showStrings <AFFBE>
> (setq sarray '("foo" "bar" 0))
("foo" "bar" 0)
> (showStrings (pack "lu lu lu" sarray))
-> foo
-> bar
0
>
The last 0 is the return value from the function (void).