From: Phrogz <gavin@...>
Date: 2006-10-06T22:50:11+09:00
Subject: Re: Compound Parallel Operators

Martin Coxall wrote:
> > Wouldn't it be nice if all compound operators worked with parallel
> > assignment?
> > a,b,c *= x,y,z
> > would thus be interpreted as
> > a *= x
> > b *= y
> > c *= z
>
> That's a scary bit of perlish implicitness. They call it "Do What I
> Mean", when actually it's "Attempt to Do What You Think I Mean Getting
> it Right 60% of The Time".

Where do you draw the line? By that rationale, Isn't "a *= b" or "a,b =
x,y" DWIM?

I would say DWIM only becomes a problem when the interpretation of a
particular syntax varies based on the context. In this case (and a*=b
and a,b=x,y) the language has one and only one clear interpretation.

Now, I would consider it a valid argument to say "Let's not codify a
particular interpetation of some syntax that conflicts with another
reasonable interpretation, because it will be surprising to a notable
percentage of programmers." Would anyone say that they personally have
a different expectation for what "a,b += x,y" might mean?


> You know, time taken to type out expressions is not the limiting
> factor in a programmer's efficiency.

No, but it certainly contributes. I don't write 'block'-based functions
in JavaScript because it is prohibitively annoying to type an anonymous
function:

myArray.each( function( a ){ alert( a ) } );

I'm not going to say that terser is always better, but one of Ruby's
strong suits is its ability to succinctly express what you mean.

Death by a thousand paper cuts is still death, and every little bit of
polish helps. IMO.