Re: APL & Programming Concepts

Polivka@[EMAIL PROTECTED]
 wrote:
>  <snip>
> 
> Stage 4.  Application Development
> 	At this stage of the use of APL, there is a need to interact with the
> non-APL world with its COM, DLL, OLE, API, etc.  Performance could
> become an issue.  Looking for good outside techniques comes into
> play.  (See System Design with APL+ WIN)  Only at this point could
> computer science issues such as typing become a concern.
 >
 >  <snip>

wrong

it is NOT "only at this point"

even before leaving a wholly APL environment, I might wish to define a 
"rational" datatype, represented by a pair of integers

and then, of course, I shall want to be able to (re)define 
multiplication, so that A×B can accept rational arguments, and deliver a 
rational result

I don't want to use named cover functions for rational multiplication, 
any more than I want to use them for complex multiplication

your vision of "typing" seems to be limited to the static typing 
facilities currently available in most compiled languages

liberate your thinking -- what if you could strongly type a variable at 
runtime? what if you could define new types at runtime? what if you 
could extend primitives to cover these new datatypes?

/phil

P.S: you ignored the need to validate actual values in a function call