In re the discussion of $^O, etc, etc, I'd like to throw out
some ideas on these line noise features and (for lack of a better
name) perl control values.
IMHO there are two distinct sets of problems here. One is that
the existing $[linenoise] vars are horrible names and really need
some syntactic sugar. `use English' is a help, but it's limited
and requires Yet Another Module be loaded when you compile. The
other set is that some vars are:
o useless
o unused (as far as we know)
o duplicated by other features
o standing in the way of advance because of backwards compatibility
o hard to deprecate without nagging the crap out of users running
the programs
I'd prefer that we break these vars out into a set of hashes with
appropriate names:
$PERL_CORE{warnings} vs $^W
$PERL_CORE{version} vs $^V
$PERL_FORMATS{name} vs $^
$PERL_FORMATS{lines_left} vs $-
These ought to be `protected' in the sense that one could change
the value of an entry, but not remove/add an entry to these hashes.
The result in some sense this mimics what `use English' does, but
gives us some additional wins:
o no need for Yet Another Module to be loaded
o it promotes code readability
o probably promotes core Perl maintainability
o should we move formats (or any similar current core functionality)
to a loadable module, this neatly encapsulates all the data with
a single referenced name (this idea shamelessly ripped off from
common TCL usage)
o solves problems with $<linenoise> variable proliferation
o promotes introspection - its easy to determine what's possible in
a given `module' via ``foreach $key ( %PERL_CTL )''. Then you can
just look them up in the manual. :-)
`use strict foo' should set $PERL_STRICT{foo}, etc. Then we dynamicly
manipulate it by manipulating the hash, not by sprinkling `use strict'
lines around the place.
For deprecation, we should have a %PERL_DEPRECATED{mod}{thing} hash as
well. `mod' is `CORE', `FORMATS', etc, as above. A value of 0 means the
function is actually gone, 1 means it's disappearing next major release,
2 mean next minor, etc. The programmer can control what happens when
the feature is used by setting a %PERL_DEPRECATED{mod}{warning} value
to 0 for default, 1 for once, 2 for never, etc, etc.
