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Re: Constructor rationale questions
On Tue, 20 Sep 2005, Michael Sperber wrote:
I don't understand how your response fits the document. You talk
about hiding identifiers, the rationale in the draft is about
Sorry, I should have been more clear. Perhaps a better counterexample is to be
found in SRFI-76 itself:
"If the custom field initialization were omitted, it would still be possible to
perform custom initialization by writing a separate constructor procedure, which
would wrap a record type's actual constructor. However, this creates the need
for an extra procedure name which is not part of the record type's definition.
This means that extensions which deal with the record type's definition (such
extensions to support keyword arguments, etc.) don't have access to the record
type's actual constructor."
I have not read the reference implementations in detail, but presumably they
construct the syntactic layer on top of the procedural substrate. Yet the
procedural substrate makes no reference to a custom constructor. Doesn't this
contradict the last line above by showing that you can build a layer that allows
extensions with access to custom constructors from a layer that doesn't store
By the way, I think the two occurrences of "actual" in the above quote
were meant to denote different things.