[PRL] values and expressions

[Sam Tobin-Hochstadt]

On Sun, 2005-10-23 at 00:16 -0400, Dave Herman wrote:
> Is it a really bad thing not to have the values of a language be a 
> subset of the expressions?

Do you mean 'the programmer-expressible expressions'?  If so, then lots
of languages have this property.  Consider a language like mzscheme, but
with the ability to provide arbitrary constructors for structs.  Then if
you have a struct like this:

(define-struct foo (a) 
  (init: (lambda () (initialize (current-seconds)))))

Then the value produced by the expression (foo) can't be represented as
a programmer-expressible value.  

sam th