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SEQUENCE-FUNCTIONS-EXCLUDE-ARRAYS (Version 4)
- To: Dave.Touretzky@C.CS.CMU.EDU
- Subject: SEQUENCE-FUNCTIONS-EXCLUDE-ARRAYS (Version 4)
- From: "Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>
- Date: Mon, 16 Nov 1987 10:22 EST
- Cc: CL-Cleanup@SAIL.STANFORD.EDU
- In-reply-to: Msg of 16 Nov 1987 01:57-EST from Dave.Touretzky
- Sender: FAHLMAN@C.CS.CMU.EDU
I don't understand Fahlman's objection to calling arrays sequences. We've
considered every sequence function in CLtL, and extended them to arrays in
all the cases that made sense, which is all cases except when the result
would be a sequence that could have a diferent number of elements than
the input sequence. Given this step, we should either admit that arrays
are sequences, or else rename the sequence functions to ``sequence or array
functions.''
When we consider a sweeping change in the type hierarchy, it is
necessary to scan the entire manual for occurrences of "sequence" to
make sure there's not some damned little comment that will cause
trouble. Even then, there are probably some gotchas. Have you done
this?
Rearranging the type hierarchy is a big incompatible step. The
extensions to the various sequence functions were of marginal value, but
when considered as a minor extensions, the convenience probably
outweighs the cost. If people feel that changes in the type hierarchy
are a necessary part of this extension, then a whole new set of
considerations come into play. I think that the added convenience is
not sufficient to justify a change in the type hierarchy -- at least,
the case has to be considered much more carefully.
-- Scott