Eliminating assignments and variable syntax (accessors)
bparsia at email.unc.edu
Thu Aug 12 12:48:37 UTC 1999
At 10:55 PM -0400 8/11/99, Lex Spoon wrote:
>Well, it's certainly open to discussion :) I'd think it best to count the
>first indent as just part of method definition. So to get a block inside a
>method, you'd have to add *another* indentation, like this:
> | x y z |
> x := 1
> y := 2
> z := 3
Blargh! That's gross! Imagine the errors! You can't *tell*, without a
comment, whether this is a misindentation or a block. *Silent*, *SEMANTIC*
errors due to copy and paste are evil. Python doesn't have *that* problem.
I *think* that *mere* indentation doesn't generate a new block in python.
Indendation replaces the role of braces in C or begin...end in Pascal--you
have *keywords* indicating *what sort* of block you're dealing with
(neither has closures, even ersatz ones, so this problem doesn't crop up).
And, IIRC, you have a *colon* marking the start, e.g.,:
if bar == 3:
return bar * 10
So, really, the opening delimiter of a block is something like *colon*
newline, rather than just new line. (I get bit by this all the time!)
>This syntax also works out fine for storing a block into a variable:
> | b x y |
> b :=
> x := 1
> y := 2
>It doesn't *look* real nice, but the fact that it's different is surely a
However big a contributer it may be, it's contribution is *totally* swamped
by the contribution of the intrinsic butt-ugliness of it :) Ugh. Espeically
with the caret making the "b"s visually misalign!
>Unfortunately, as you point out, it's tricky to send a message directly to
>a block. Hadn't thought about that one... Tough tough tough.... Maybe it
>would be worth living without this ability, just to have a syntax that is
>easier to scan through?
Maybe...but this syntax *isn't* easier to scan through!
>Well, I for one am not yet convinced, but it still seems like a neat idea.
>For languages with lots of control structure, like Python, the code comes
>out looking *really* elegant.
I don't know about *elegant*. It surely comes out *consistent* which is
nice. I find Python rather syntax heavy and the main advantage of the
whitespace stuff is to lighten it a bit (since in *any* language, if you're
sane, you'll use whitespace & indentation to pragamtically indicate block
structure; Python merely turns the pragmatics into syntax, which has some
I know other langauges use whitespace "Pythonically" (ML? Icon?) but I have
little to no experience with them.
> But is it useful in a language like Smalltalk, where blocks are so
>important and where there is next to nil syntax?
No. :) I'd say it's not useful in Lispy languages either, where indentation
plays a huge pragmatic role. I *don't* like the idea, for example, of
*eliminanting* the parens in an outlining editor (as some have done).
Rather *augmenting* them seems more sensible.
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