Re: another take on hackers and painters

[Scott McKay <address@hidden>]

At 3:15 PM -0500 5/20/03, mcguire@cs.utexas.edu wrote:
>  > Clerical programmers [...] will not know what to do with the freedom
>>  given by things such as dynamic typing.
>
>Ok, so I'm none too bright.  What exact freedoms do you get with dynamic
>typing?  It seems like a type problem is going to result in a broken
>program either way, so you still have to think about types and making
>sure the right collection of stuff gets put in the right place.  The
>only real advantages I can see are:

In the context of a lightweight language, you get to
get things working faster.  I understand that in real
"software engineering" this is not necessarily a goal,
but getting small programs working quickly is incredibly
useful.  It's also the case that understanding the type
signature of a whole program from its very beginning can
be quite hard.  Being able to delay doing this can be
more than a little useful in an exploratory mode.

Dylan tried -- quite successfully, IMO -- to have it
both ways, by treating static typing as a compile-time
optimization of dynamic typing.

>* A dynamic type system makes the language implementation easier.
>Writing a decent static type checker is harder than a decent dynamic
>type checker.
>
>* Macros:  I know staticly typed macro-ish systems exist, but with the
>execption of camlp4, I don't know of any that are a standard part of a
>language or even a standard part of an implementation.  Again, dynamic
>typing makes it easier, better integrated, and thus more common.
>
>
>Tommy McGuire