What is Expressiveness in a Computer Language

[genea]

Joe Marshall wrote:
{...}
> The issue of `static vs. dynamic types' comes up about twice a year in
> comp.lang.lisp  It generally gets pretty heated, but eventually people
> come to understand what the other person is saying (or they get bored
> and drop out of the conversation - I'm not sure which).  {...}

  I think that the thing about "Language Expressiveness" is just so
elusive, as it is based on each programmers way of thinking about
things, and also the general types of problems that that programmer is
dealing with on a daily basis.  There are folks out there like the Paul
Grahams of the world, that do wonderfully complex things in Lisp,
eschew totally the facilities of the CLOS, the lisp object system, and
get the job done ... just because they can hack and have a mind picture
of what all the type matches are "in there head".  I used to use forth,
where everything goes on a stack, and it is up to the programmer to
remember what the heck the type of a thing was that was stored there...
maybe an address of a string, another word {read function}, or an
integer...  NO TYPING AT ALL, but can you be expressive in forth... You
can if you are a good forth programmer... NOW that being said, I think
that the reason I like Haskell, a very strongly typed language, is that
because of it's type system, the language is able to do things like
lazy evaluation, and then though it is strongly typed, and has
wonderful things like type classes, a person can write wildly
expressive code, and NEVER write a thing like:
    fromtoby :: forall b a.
            (Num a, Enum a) =>
            a -> a -> a -> (a -> b) -> [b]
The above was generated by the Haskell Compiler for me... and it does
that all the time, without any fuss.  I just wrote the function and it
did the rest for me... By the way the function was a replacement for
the { for / to / by } construct of like a C language and it was done in
one line...  THAT TO ME IS EXPRESSIVE, when I can build whole new
features into my language in just a few lines... usually only one
line..   I think that is why guys who are good to great in dynamic or
if it floats your boat, type free languages like Lisp and Scheme find
their languages so expressive, because  they have found the macro's or
whatever else facility to give them the power...  to extend their
language to meet a problem, or fit maybe closer to an entire class of
problems.. giving them the tool box..  Haskeller', folks using Ruby,
Python, ML, Ocaml, Unicon.... even C or whatever... By building either
modules, or libraries... and understand that whole attitude of tool
building.. can be equally as expressive "for their own way of doing
things".  Heck, I don't use one size of hammer out in my workshop, and
I sure as hell don't on my box...   I find myself picking up Icon and
it's derivative Unicon to do a lot of data washing chores.. as it
allows functions as first class objects... any type can be stored in a
list...  tables... like a hash ... with any type as the data  and the
key... you can do    things like
i := 0
every write(i+:=1 || read())
which will append a sequence of line numbers to the lines read in from
stdin.. pretty damn concise and expressive in my book...  Now for other
problems .. Haskell with it's single type lists... which of course can
have tuples, which themselves have tuples in them with a list as one
element of that tuple... etc.. and you can build accessors for all of
that for function application brought to bear on one element of one
tuple allowing mappings of that function to all of that particular
element of ... well you get the idea.. It is all about how you see
things and how your particular mindset is...  I would agree with
someone that early on in the discussion said the thing about "type's
warping your mind" and depending on the individual, it is either a good
warp or a bad warp, but that is why there is Ruby and Python, and
Haskell and even forth... for a given problem, and a given programmer,
any one of those or even Cobol or Fortran might be the ideal tool... if
nothing else based on that persons familiarity or existing tool and
code base.   

enough out of me... 
-- gene