Re: proposal: rename 'subtype' declarator to 'set'
On Fri, 11 Nov 2005, Eric wrote: I think 'subset' might be a nicer colour for this bikeshed. For an [snip] Ehh. By that definition arn't all sets subsets? Anyway I didn't see It depends on the axiomatic model of your choice. Speaking of which it is perhaps not terribly OT to discuss here which one to mimic for Perl6 -provided that it is sensible/advisable/useful to mimic one axiomatic set theory at all-: a class based one (a' la Goedel-Bernays) or a Universe based one? Michele -- The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time. - Ninety-Ninety Rule
Re: proposal: rename 'subtype' declarator to 'set'
On Wed, Nov 09, 2005 at 01:45:21PM +0100, TSa wrote:
: So, why not call the thing what it is---a set *type* declarator!
:
: set SmallInt of Int where { abs 10 };
:
: set SomeNums of Num = (3.14, 4, 89, 23.42);
:
: set Bit of Int = (0,1);
Interesting idea. I expect a bit of interference from the verb
to set, but that's probably not a showstopper, particularly since
the next token isn't a variable.
: Enumerations are then just sets of pairs
:
: set NumWords of Pair = { zero = 0, one = 1, two = 2, three = 3 };
: # or with ( ... ) instead?
:
: enum NumWords = zero one two three; # short form of the above
:
:
: Without the 'of' it doesn't look so good
:
: set Num SomeNums = (3.14, 4, 89, 23.43);
:
: but OTOH, it looks nicely like
:
: my Num @SomeNums = (3.14, 4, 89, 23.43);
:
: my Int %NumWords = { zero = 0, one = 1, two = 2, three = 3 };
:
: YMMV, though ;)
I'd like to lose the = if possible. We don't say
sub foo = { ... }
: Does that work? Perhaps even while maintaining compatibility with the
: set *value* creator sub that exists in Pugs, IIRC?
:
: my $x = set( 1, 2, 3 ); # $x contains a set reference at best
They can perhaps be unified, especially if we lose the = noise. Probably
have to require the parens syntactically though, just as though you'd said
my $x = my($a,$b,$c);
Larry
Re: proposal: rename 'subtype' declarator to 'set'
On 12/11/05, Larry Wall [EMAIL PROTECTED] wrote:
On Wed, Nov 09, 2005 at 01:45:21PM +0100, TSa wrote:
: So, why not call the thing what it is---a set *type* declarator!
:
: set SmallInt of Int where { abs 10 };
:
: set SomeNums of Num = (3.14, 4, 89, 23.42);
:
: set Bit of Int = (0,1);
Interesting idea. I expect a bit of interference from the verb
to set, but that's probably not a showstopper, particularly since
the next token isn't a variable.
I think 'subset' might be a nicer colour for this bikeshed. For an
extra three characters you lose the confusion with to set, and it
highlights the fact that you're (usually) declaring a *constrained*
subset of the original type.
Stuart
Re: proposal: rename 'subtype' declarator to 'set'
I think 'subset' might be a nicer colour for this bikeshed. For an extra three characters you lose the confusion with to set, and it highlights the fact that you're (usually) declaring a *constrained* subset of the original type. Stuart Ehh. By that definition arn't all sets subsets? Anyway I didn't see any confusion with to set at all. subset confused me quite a bit though. Besides it might not be a sub set at all. set types full half quarter jumbo automatic; You could call that a subset of words, but i think this has extra clarity over: subset types full half quarter jumbo automatic; First thing i think when seeing that is...subset of what? where is the larger set defined? Of course I have no knowledge of set theory at all, just a humble programming giving his input.
proposal: rename 'subtype' declarator to 'set'
Larry Wall wrote:
On Mon, Nov 07, 2005 at 01:05:16PM +0100, TSa wrote:
: With the introduction of kind capture variables ^T we could complety
: drop the subtype special form. As you pointed out the adding of
: constraints happens with the where clause anyway. Thus we return to
: the usage of the compile time name assignment form
:
: ::Blahh ::= ::Fasel where {...}
:
: where the :: in all cases means working on the MIR (Meta Information
: Repository) which is the world of names (In Russian, Mir (Мир) means
: peace, and connotes community. --- cited from Wikipedia).
Except that a type declarator can remove the need for all those extra ::
markers. (Actually, the ::Fasel can be presumably written Fasel if
Fasel is already declared, so the only strangeness is on the left.
We could hack identifier-left-of ::= like we did identifier-left-of =,
or we could turn ::= into more of a general alias macro idea. But I think
people generally like declarators out to the left for readability.)
So, why not call the thing what it is---a set *type* declarator!
set SmallInt of Int where { abs 10 };
set SomeNums of Num = (3.14, 4, 89, 23.42);
set Bit of Int = (0,1);
Enumerations are then just sets of pairs
set NumWords of Pair = { zero = 0, one = 1, two = 2, three = 3 };
# or with ( ... ) instead?
enum NumWords = zero one two three; # short form of the above
Without the 'of' it doesn't look so good
set Num SomeNums = (3.14, 4, 89, 23.43);
but OTOH, it looks nicely like
my Num @SomeNums = (3.14, 4, 89, 23.43);
my Int %NumWords = { zero = 0, one = 1, two = 2, three = 3 };
YMMV, though ;)
Does that work? Perhaps even while maintaining compatibility with the
set *value* creator sub that exists in Pugs, IIRC?
my $x = set( 1, 2, 3 ); # $x contains a set reference at best
--
$TSa.greeting := HaloO; # mind the echo!
