From: Allison Randal <[EMAIL PROTECTED]>
Date: Thu, 29 May 2008 02:22:37 +0200
. . .
Any of these alternatives can be marked as optional. Positional
parameters must come before all lookahead or named parameters. Lookahead
parameters must come before all named parameters. Positional, lookahead,
and named parameters must come before any slurpy parameters. And
required parameters must come before all optional parameters.
Allison
These ordering constraints could be summarized as follows:
positional < lookahead < named
required < optional
I assume you meant "order by positionality, then by optionality";
otherwise, ordering a required named parameter vs. an optional
positional parameter would be tough. That yields the following
declaration order (ignoring :slurpy):
Pos? Named? Reqd? => Example
yes no yes => .param pmc A
yes no no => .param pmc B :optional
yes yes yes => .param pmc C :lookahead('c')
yes yes no => .param pmc D :optional :lookahead('d')
no yes yes => .param pmc E :named('e')
no yes no => .param pmc F :optional :named('f')
I can see why B has to be after A and before C, and I assume ":lookahead
before :named" makes the implementation easier, but I can't see the need
for any particular ordering of C vs. D, or E vs. F. Am I missing
something? Just curious,
-- Bob Rogers
http://rgrjr.dyndns.org/
