“Simon Strandgaard” neoneye@adslhome.dk schrieb im Newsbeitrag
news:20040506182920.02fd89f5.neoneye@adslhome.dk…
“Simon Strandgaard” neoneye@adslhome.dk schrieb im Newsbeitrag
news:20040506120251.43669286.neoneye@adslhome.dk…
homepage:
http://raa.ruby-lang.org/list.rhtml?name=iterator
download:
http://rubyforge.org/frs/?group_id=18&release_id=467
External iterators with some STL inspiration.
[snip]
Great! This looks good. I’d just do some small interface changes.
I am always open to suggestions 
Move Array#create_iterator to Enumerable and rename it to
Enumerable#iterator (we’re lazy typers) if possible.
Good suggestion… will change it.
Alternatively you could provide this wrapper:
module Enumerable
def iterator; Iterator::Continuation.new(self, :each); end
end
Also a good suggestion… will change it.
Make Iterator::Concat#initialize to be able to do
iterator = Iterator::Concat.new(i1, i2, i3) # brackets removed
iterator = Iterator::Concat.new(i1, ary2, i3)
Major dillema, I don’t know how to do it.
My current Concat#initialize looks like “def initialize(iterators,
position=nil)”
Ah, I see.
If I do “def initialize(*iterators, position=nil)”… that won’t work ?
irb(main):001:0> def m(*args, x=nil)
irb(main):002:1> p args
irb(main):003:1> p x
irb(main):004:1> end
SyntaxError: compile error
(irb):1: syntax error
def m(*args, x=nil)
^
(irb):1: syntax error
from (irb):1
irb(main):005:0>
Any hints on how to pass ‘position’ to initialize ?
def init(*args)
if Numeric === args[-1]
pos = args[-1]
args.slice!(-1, 1)
else
pos = nil
end
puts “iterators: #{args.inspect}”
puts “position : #{pos.inspect}”
end
irb(main):066:0> init “a”,“s”,1
iterators: [“a”, “s”]
position : 1
=> nil
irb(main):067:0> init “a”,“s”
iterators: [“a”, “s”]
position : nil
=> nil
irb(main):068:0> init
iterators:
position : nil
=> nil
Or even
def init2(*args)
pos = nil
iters =
args.each do |arg|
case arg
when Numeric
raise ArgumentError, “duplicate start positions” if pos
pos = arg
when Iterator # place appropriate type(s) here
iters << arg
when Enumerable
iters << Iterator::Continuation.new(arg, :each)
else
raise ArgumentError, “Don’t know what to do with #{arg.inspect}”
end
end
puts “iterators: #{iters.inspect}”
puts “position : #{pos.inspect}”
end
Nice to have but maybe not worth the effort:
Iterator#reset
Its already there… #first and #last both resets the iterator.
Ooops, overlooked that one.
Thanks for these great suggestions… keep them coming.
You’re welcome.
Kind regards
robert
···
“Robert Klemme” bob.news@gmx.net wrote:
