I have been using a little extension of Array that I wrote for awhile:
class Array
def and?() each{|e| return false unless yield e }; true end
def or?() each{|e| return true if yield e }; false end
end
Then I discovered Array#detect because of a post by Jason Creighton, he
used it in his WrapHash class (btw, nice class Jason).
Why thank you.
So I run to irb
and played with #detect. It’s cool and I’ll be using it but it’s not a
replacement for my #and? and #or? methods. I still have to mess with
Array myself.
Okay, any? and all? were mentioned in other posts but ‘ri’ is your
friend. The 1.8 version is on rdoc.sf.net, go to the download page and
scroll down to the bottom. Here’s what you can do with it:
~$ ri Enumerable
This is a test ‘ri’. Please report errors and omissions
on http://www.rubygarden.org/ruby?RIOnePointEight
···
On Tue, 26 Aug 2003 03:17:32 +0900 mgarriss mgarriss@earthlink.net wrote:
module: Enumerable
The Enumerable mixin provides collection classes with several
traversal and searching methods, and with the ability to sort. The
class must provide a method each, which yields successive members
of the collection. If Enumerable#max, #min, or #sort is used, the
objects in the collection must also implement a meaningful <=>
operator, as these methods rely on an ordering between members of
the collection.
all?, any?, collect, detect, each_with_index, entries, find,
find_all, grep, include?, inject, map, max, member?, min,
partition, reject, select, sort, sort_by, to_a, zip
any? is a unique method so we don’t have to say “Enumerable#any?”
~$ ri any?
This is a test ‘ri’. Please report errors and omissions
on http://www.rubygarden.org/ruby?RIOnePointEight
-------------------------------------------------------- Enumerable#any?
enumObj.any? [{| obj | block } ] → true or false
Passes each element of the collection to the given block. The
method returns true if the block ever returns a value other that
false or nil. If the block is not given, Ruby adds an implicit
block of {|obj| obj} (that is any? will return true if at least one
of the collection members is not false or nil.
%w{ ant bear cat}.any? {|word| word.length >= 3} #=> true
%w{ ant bear cat}.any? {|word| word.length >= 4} #=> true
[ nil, true, 99 ].any? #=> true
~$ ri collect
This is a test ‘ri’. Please report errors and omissions
on http://www.rubygarden.org/ruby?RIOnePointEight
The method named `collect’ is not unique among Ruby’s classes and
modules:
Array#collect, Enumerable#collect
Oops, Array implements its own #collect, we have to be more specific
~$ ri Enumerable#collect
This is a test ‘ri’. Please report errors and omissions
on http://www.rubygarden.org/ruby?RIOnePointEight
----------------------------------------------------- Enumerable#collect
enumObj.collect {| obj | block } → anArray
Returns a new array with the results of running block once for
every element in enumObj.
(1..4).collect {|i| i*i } #=> [1, 4, 9, 16]
(1..4).collect { "cat" } #=> ["cat", "cat", "cat", "cat"]
This incredibly handy tool is, of course, by Dave Thomas.
Jason Creighton