Re: Argument scope
On Mon, 6 Dec 2010, Andreas Leitgeb wrote:
Tom Anderson <twic@urchin.earth.li> wrote:
BufferedWriter out;
with (out) {
write("foo");
newLine();
write("bar");
newLine();
}
Which basically redefines the implicit target of invocations inside its
scope from 'this' to something else. It's a little wordier.
Pascal had it already.
You snipped the bit where i said we were stealing this from Delphi!
I learnt Pascal before I got in touch with C, and bemourned the lack of
"with" in C. I'd love to finally see it at least in Java :-)
I'm now swinging back against it:
http://stackoverflow.com/questions/514482/is-delphi-with-keyword-a-bad-practice
Although i see Visual Basic has a version which combines Pascal's 'with'
with my idea about leading full stops:
http://stackoverflow.com/questions/71419/whats-wrong-with-delphis-with/71470#71470
So you write:
with (out) {
.write("foo");
.newLine();
.write("bar");
.newLine();
}
This is better than the Smalltalk ripoff, because it makes the receiver
clearm and it's better than the Pascal ripoff, because it defeats the
error where things unexpectedly come into scope, mentioned in the first
StackOverflow link above.
If an object were designed for sequences of void method-calling, then it
should have its methods return "this", instead, so one could do
ref.callThis().callThat().callAnother(). ...
A construction which i hate with a burning passion.
...
How does that have any semantic meaning?
semantic meanings are overrated :-)
PS: there's also:
BufferedWriter _ = ...;
_.doThis(); _.doThat(); ...
or, using short names like "b", or "bw".
GET OUT.
tom
--
a moratorium on the future