From: matz@... (Yukihiro Matsumoto)
Date: 2000-12-04T00:15:47+09:00
Subject: [ruby-talk:6768] Re: printing/accessing arrays and hashes

Hi,

In message "[ruby-talk:6678] Re: printing/accessing arrays and hashes"
    on 00/12/01, Raja S. <raja@cs.indiana.edu> writes:
|---------------------------------------------------------------------------
|
|Problem:  Array/hash access via #[] (i.e.m a[i], h[i]) does not raise an
|          exception for out of range indices/keys.  
|
|Fix:      Hash#fetch raises an exception but unfortunately nothing equivalent
|          for arrays. 

Probably Hash#fetch equivalent for Array is good answer.  What do you
guys think is the best name for it?  Array#get? Array#fetch?

|Quirk:    Printing hash literals as the first argument to print causes
|          syntax problems: 
|
|          print {'a'=>1, 'b'=>2}
|
|Fix:      Precede by an empty string.
|          print "", {'a'=>1, 'b'=>2}

Or use parentheses.  If there's good way to distinguish blocks and
hashes, without confusing yacc generated parser, I'd like to know.

|---------------------------------------------------------------------------
|
|Problem;  a[i..j / i...j / i,cnt] returns nil instead of [] for non-existing
|          segments.
|
|          Creates a problem for iterators as #each isn't defined for nil.
|
|Fix:      Don't know of a clean one.
|
|Comment:  Either #each needs to be defined for nil [Doesn't feel right]
|
|          Or a[i..j / i...j / i,cnt] should return the empty array, [], for out
|          out of bounds segments. [This feels right] 
|
|---------------------------------------------------------------------------

This is iteresting comment.  Let's discuss.  If index is out of bound,
what should [] return?  nil or empty array?

							matz.