From: Michael Neumann <mneumann@...>
Date: 2004-09-30T23:18:37+09:00
Subject: Re: Too Many Ways?

Gavin Kistner wrote:
> On Sep 30, 2004, at 7:12 AM, Chris Pine wrote:
> 
>> (Yes, if you are teaching Ruby to a functional programmer, you use map 
>> instead of collect (are those really the same? I just always avoided 
>> collect:  wrong english word, I think), but you still teach them only 
>> *one* of them.)
> 
> 
> Funny, I never understood what #map did. People used it all the time and 
> it baffled me. I kept saying "I should learn this method, because people 
> keep showing how to use it for powerful, terse solutions, but...I'm 
> baffled."

How would you feel if you were forced to use #map all the time? That's 
why I think it's good that Ruby follows TMTOWTDI. Python for example 
AFAIK only provides map() and #collect comes from Smalltalk, I think. 
Now, everyone from both worlds feel happy in Ruby ;-)

Of course when reading others' sourcecodes you'll get into trouble. But 
I don't as often as I write new code.

> Then someone showed me the #collect method, and I fell in love. It's 
> awesome. I extended arrays in Javascript to use it, I love it so much.
> 
> ...it was a week later than I pulled up the documentation and saw that 
> they're the same thing. Something about 'map' made absolutely no sense 
> to me (it implies a hash-like permanent connection between the old and 
> the new), and collect made perfect sense (go traipsing through the 
> entire field of daisies, picking up only the best ones).
> 
> So if we were deprecating duplicates, I vote to get rid of #map.
> (This is the part where 100 rubyists say "No! #collect sucks, #map is 
> king!" and my entire argument for less duplication is shot down by the 
> fact that people like different things.)

Well, of course both #map and #collect behave in the same way, but I'm 
not sure I use both of them in the same way! That's a bit similar to 
"{...}" and "do ... end" block, which are similar but used by some 
people in different situations. I think, I use #map when the result is 
short and very similar to the source (e.g. {|a| a+1}), and #collect if 
it spans multiple lines and the calcluation is big.

Regards,

   Michael