[lextypes] DLL proof of concept

[John Cowan]

I wrote:

> There are additional interfaces for implementing parameterized datatypes, 

Oops, I see that DTLL *does* allow parameterized datatypes.  So add a fourth
interface, DatatypeBuilder.  A DatatypeLibrary can be asked to return a
DatatypeBuilder given a name.  Then the DatatypeBuilder provides two methods,
one to specify a parameter name and value, and the other to return a
Datatype that encapsulates the base type and all the values.  The other
DatatypeLibrary method, returning a Datatype directly, is just shorthand for
getting a DatatypeBuilder and asking it to deliver a Datatype immediately
with no parameters set.

-- 
What is the sound of Perl?  Is it not the       John Cowan
sound of a [Ww]all that people have stopped     jcowan at reutershealth.com
banging their head against?  --Larry            http://www.ccil.org/~cowan