What is Expressiveness in a Computer Language

[Darren New]

Matthias Blume wrote:
> In Danvy's solution, the format argument is not a string.

That's what I said, yes.

>>You can't read the printf format from a configuration file
>>(for example) to support separate languages.

> You don't need to do that if you want to support separate languages.

That's kind of irrelevant to the discussion. We're talking about 
collections of dynamically-typed objects, not the best mechanisms for 
supporting I18N.

> Moreover, reading the format string from external input is a good way
> of opening your program to security attacks, since ill-formed data on
> external media are then able to crash you program.

Still irrelevant to the point.

> I am sure one could adapt Danvy's solution to support such a thing.

I'm not. It's consuming arguments as it goes, from what I understood of 
the paper. It's translating, essentially, into a series of function 
calls in argument order.

> Obviously, a Danvy-style solution (see, e.g., the one in SML/NJ's
> library) is not necessarily structured that way.  I don't see the
> problem with typing, though.

You asked for an example of a heterogenous list that would be awkward in 
a statically strongly-typed language. The arguments to printf() count, 
methinks. What would the second argument to apply be if the first 
argument is printf (since I'm reading this in the LISP group)?

-- 
   Darren New / San Diego, CA, USA (PST)
     My Bath Fu is strong, as I have
     studied under the Showerin' Monks.