comp.lang.functional Google Group

Re: Interactive ML weirdness

2009-12-18T15:35:45Z

[snip]
[snip]
I won't cover ground that others have already done so ably. You can't
modify running programs in any straightforward way that I know of, but
perhaps you can accomplish what you want by creating a higher-order
function which takes as inputs the names in question and returns as
output a function which implements the algorithm with the bindings

Re: Interactive ML weirdness

2009-12-18T14:30:15Z

What you've assumed to be "the same scope" is actually different scopes.

Re: Interactive ML weirdness

2009-12-18T10:02:19Z

Strictly speaking, you start a new scope whenever you define a new
variable in a let-construct with multiple bindings:
let
val x = e1
val x = f(x)
in g(x) end
is expanded into
let
val x = e1
in
let
val x = f(x)
in g(x) end
end
In the expanded version it is clear that a new scope is introduced.

Re: Interactive ML weirdness

2009-12-18T08:30:31Z

It is useful in conjunction with features like open/include, where
requiring disjointness would be a major pain (in fact, OCaml imposes
certain restrictions on this, and it *is* sometimes painful). It also
is useful for certain idioms of functionally "updating" values without
having to reinvent new names all the time. For example:

Re: Interactive ML weirdness

2009-12-18T05:11:34Z

And I thought I understood lexical scoping and closures... But, the
behavior I'm remarking on is that ML allows a name to have multiple
bindings within the same scope. In other words, a single scope can
contain multiple objects with the same name. I don't understand how
that is beneficial.
Also, with redefinable bindings, the result of a program depends on

Re: Interactive ML weirdness

2009-12-18T00:39:10Z

There's nothing bizarre about this.
Functional languages don't have assignment, they have binding. In a
typical imperative language, a name refers to an lvalue (i.e. a region of
memory). An assignment operation modifies the named lvalue. In a
functional language, a name is bound to a value. Rebinding the name causes

Call for Papers & Sessions: The 2010 International Conference on Software Engineering Research and Practice (SERP'10), USA, July 2010

2009-12-17T15:55:55Z

It would be greatly appreciated if this announcement could be
shared with individuals whose research interests include
software engineering research and practice. Thanks.
-------
CALL FOR PAPERS
and
Call For Workshop/Session Proposals

Call for Papers Reminder (extended): IAENG International Conference on Computer Science (ICCS 2010)

2009-12-17T09:29:37Z

CFP Reminder (extended): IAENG International Conference on Computer
Science (ICCS 2010)
Draft Manuscript submission deadline (extended): 30 December, 2009
Camera-Ready papers & Pre-registration deadline: 10 January, 2010
ICCS 2010: 17-19 March, 2010
[link]
All submitted papers will be under peer review and accepted papers

Re: Interactive ML weirdness

2009-12-17T07:31:05Z

It's a feature. Lexical scoping is the only reasonable semantics you
can have in a typed language.
Disallowing shadowing would be a very bad idea, as it would make code
extremely fragile: you could break a perfectly fine piece of code just
by *adding* something somewhere else.
If you want to be able to change functions while the program is

Interactive ML weirdness

2009-12-17T00:01:28Z

I've discovered the bizarre behavior of interactive ML when redefining
objects. It allows you to create a new object with a repeated name,
but objects referencing the name from an earlier stage keep it with
the old value.
I know ML is said to have static assignment, but I expected something
like "Error: Can't define foo because it already exists." The default

Re: is laziness leakier?

2009-12-14T20:50:48Z

I suspect that you mean "eagerness".
Strict vs non-strict is an issue of semantics. Lazy vs eager is an
implementation issue.
It's possible to make use of eager evaluation in a language with
non-strict semantics, but you have to be careful (i.e. only use it if you
can determine that it is safe to do so).

is laziness leakier?

2009-12-14T12:13:36Z

Greetings,
After having learned SML and (to a much lesser extent) Scheme I've
tried to learn a bit of Haskell. I've read through Graham Hutton's
introductory book but haven't had time to plunge into something like
"Real World Haskell" yet, so my impressions are just that -
impressions not based on deep knowledge, but this is the usenet - who

Call for Papers: The 2010 International Conference on e-Learning, e-Business, Enterprise Information Systems, and e-Government (EEE'10), USA, July 2010

2009-12-14T05:32:57Z

It would be greatly appreciated if this announcement could be
shared with individuals whose research interests include
e-learning, e-business, enterprise information systems, and
e-government. Thanks.
-------
CALL FOR PAPERS
and
Call For Workshop/Session Proposals

Re: Pure language; Term rewriting

2009-12-13T23:22:30Z

oops - it's not from Lisp. (I confuse Q with Qi ;)

Re: Pure language; Term rewriting

2009-12-13T21:54:47Z

I want just note, that term rewriting is well known technique, which
exists at least 30 years.
As I know, now the main beast in this niche is Maude. [shameless plug:
also look on termware for embedding term rewriting into Java
applications] Also most interpreters of lazy functional languages
[clean, haskell] use very similar technique of graph rewriting.