From: Daniel Berger <djberg96@...>
Date: 2005-10-23T23:57:49+09:00
Subject: Re: A comparison by example of keyword argument styles

Trans wrote:
> List is great but I don't program in Lisp because of my eyes become
> crossed in looking at it. I don't what the same thing in Ruby.
>
>   def foo( c: )  # looks bad
>
>   foo( c: :many )  # horrible!!!
>
> I don't understand why this is acceptable. Symbols are common
> arguments. Space significance is poo-poo'd everywhere else.

I could live with this particular exception.  Seriously, what are our
alternatives for keyword syntax in method calls?

"foo(x: 1)"
Pros: Probably easiest to parse.  Familiar to Smalltalkers and Lispers.
Cons: Symbols force space, look ugly.
Aside: I don't expect to see a lot of folks passing symbols to keywords
arguments in practice.

"foo(x => 1)"
Pros: Familiar syntax, fairly intuitive.
Cons: More verbose, difficult (impossible?) to distinguish from a Hash.

"foo(x = 1)"
Pros: Clean, simple, intutive.  Familiar to Pythonistas.
Cons: May very well be impossible to implement because '=' is an
expression.

"foo(x := 1)"
Pros: Avoids the SSW issue with symbols.
Cons: Unfamiliar syntax, smells like Ada.

If Evan can, by some wizardry, get '=' to work in Sydney, that is the
proposed syntax I would favor.  Otherwise, I can certainly live with
":" and a forced whitespace for symbols.

> This is terrible. Why do you not care about this Matz? Why do so many
> not seem to care about this?

He does care.  That's why he's joined this discussion in public, and
probably has some interest in seeing how Sydney does things.

Regards,

Dan