Timothy S. Nelson wrote:
On Sat, 4 Apr 2009, Darren Duncan wrote:
Speaking of libraries, I already implemented a table type ... it's
called Set::Relation/::V2 and its on CPAN right now ... for Perl 5 ...
I still have to port it to Perl 6, unless someone else wants to do
that, but I designed
Xiao Yafeng wrote:
I don't think an array of hashes and a hash of arrays could perfectly
represent a Table type.
There are several important facts of a relational model:unordered
columns and tupples, various constraints on columns. E.g. how can we
represent multi-unique constraints as an array
I don't think an array of hashes and a hash of arrays could perfectly
represent a Table type.
There are several important facts of a relational model:unordered
columns and tupples, various constraints on columns. E.g. how can we
represent multi-unique constraints as an array of hashes?
On
On Sat, 4 Apr 2009, Darren Duncan wrote:
Speaking of libraries, I already implemented a table type ... it's called
Set::Relation/::V2 and its on CPAN right now ... for Perl 5 ... I still have
to port it to Perl 6, unless someone else wants to do that, but I designed it
so that would be easy
On Fri, Apr 3, 2009 at 10:52 PM, Moritz Lenz mor...@faui2k3.org wrote:
Xiao Yafeng wrote:
1. Could I set multi-return type?like
sub test as (Int, Str) {...}
as is coercion - so to what would it coerce? Int or Str? How could the
compiler know? Or do you mean
On Sat, 4 Apr 2009, Xiao Yafeng wrote:
3. Could I define primary key for a bag variable?
All items in a Bag are primary keys, but there's no data additional
data associated with it.
I mean whether I can see Set as a table and Bag as a table with a
unique constraint? like:
subset
Timothy S. Nelson wrote:
On Sat, 4 Apr 2009, Xiao Yafeng wrote:
I mean whether I can see Set as a table and Bag as a table with a
unique constraint? like:
I think you have that backwards. A Set is conceptually like a Bag with a
uniqueness constraint, not the other way around.
Xiao Yafeng wrote:
1. Could I set multi-return type?like
sub test as (Int, Str) {...}
as is coercion - so to what would it coerce? Int or Str? How could the
compiler know? Or do you mean something like a tuple?
2. set is unordered collection of values， subset is new
Moritz Lenz wrote:
2. set is unordered collection of values， subset is new type. People are
apt to confuse the two concepts.
Note that people never write subset in their code, the write things like
sub f($x where { ... } ) and the where constructs the subset type. I
don' think that's
On Fri, 3 Apr 2009, Moritz Lenz wrote:
Xiao Yafeng wrote:
1. Could I set multi-return type?like
sub test as (Int, Str) {...}
as is coercion - so to what would it coerce? Int or Str? How could the
compiler know? Or do you mean something like a tuple?
I think
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