ghost@aladdin.com (L. Peter Deutsch) (01/02/91)
I'm puzzled about two things in the operation of the PostScript
'bind' operator.
1) The Red Book seems to imply that bind will affect the top level of
a procedure even if the procedure is read-only or execute-only, but
not interior read- or execute-only procedures. Is this really the
case?
2) Does bind affect packed arrays? If not, packed arrays are of
substantially less value for the thing I would have thought they
would be ideal for, namely, procedures.
I would welcome enlightenment on this obscure subject.
L. Peter Deutsch :: Aladdin Enterprises :: P.O. box 60264, Palo Alto, CA 94306
ghost@aladdin.com ; {uunet,sun,decwrl}!parcplace!aladdin!ghost ; (415)329-0264
"Implementation is the sincerest form of flattery."taft@adobe.com (Ed Taft) (01/06/91)
In article <38.UUL1.3#5127@aladdin.com> ghost@aladdin.com (L. Peter Deutsch) writes: >1) The Red Book seems to imply that bind will affect the top level of >a procedure even if the procedure is read-only or execute-only, but >not interior read- or execute-only procedures. Is this really the >case? Regrettably, the red book description is misleading on this point. An array that isn't writable will not be affected by bind, whether it is the top-level array or a nested one. >2) Does bind affect packed arrays? Yes, bind affects packed arrays to arbitrary depth, in spite of the fact that packed arrays are always read-only. Note that for arrays, the interpreter marks nested arrays read-only as it goes along. This is how it avoids infinite recursion if nested arrays form a circular structure. This is not necessary for packed arrays, since it's impossible to create a circular structure consisting entirely of packed arrays. Ed Taft taft@adobe.com ...decwrl!adobe!taft