🚀 go-pugleaf

In article <ROCKWELL.92Apr8231542@socrates.umd.edu>, rockwell@socrates.umd.edu (Raul Deluth Miller-Rockwell) writes:
|> [...]
|> Well, in a very real sense, all objects except identifiers are
|> statically declared.  [...]

You mean, all objects except identifiers _and_ expressions involving
identifiers.  But this is a trivial property that's shared by all
programming languages - literals and built-in intrinsics have
statically determined attributes.  If you write code involving
only literals and intrinsics, then all attributes of your program
are static - so why write a program?

|> [...]             Also, there is a class of identifiers which may
|> only be declared once.  [...]

Really?  Please present the mechanism for doing this.  In particular
however, I want the ability to declare identifiers to have _some_
fixed attributes and _some_ attributes that are allowed to vary.
For example, I want to be able to say that X is a scalar floating-point
number - those characteristics of X are fixed for the life of the 
program - but I want the actual _value_ of X to be allowed to be 
changed.

|> [...]                   Finally, note that a compiler would likely
|> create an object whose semantics are fixed.

I don't know what you mean here.  The purpose of _any_ programming
language is to define the semantics of an algorithm.  As such, the
compiler always generates something with _some_ fixed properties.
The question is whether the end user of the language has control
over which properties are fixed and which aren't.

|> [...]
|>    Expressiveness is just exactly the issue.  J does not let me
|>    express clearly those constraints that I know when I write the
|>    code.
|> 
|> It lets me express arbitrary constraints.  Of course, I have the
|> advantage of having learned the language.

Really?  Then you can tell me the very thing I keep asking and you keep 
dodging - how do I declare that a given identifier has a specific type
for the life of the program - yet its _value_ can change?

J. Giles