2009/7/2 Bil Kleb <Bil.Kleb@[...].gov> :
>  Hi,
> 
>  Given an array of integers, I need to delete all those
>  entries that are lower than the current array index.
> 
>  I first thought of the non-existent,
> 
>   array.delete_if_with_index{ |e,i| e < i }
> 
>  then,
> 
>   remove_indices = []
>   array.each_with_index{ |e,i| remove_indices << i if e < i }
>   array.delete_at( remove_indices )
> 
>  or the same, but with a fictious inject_with_index,
> 
>   remove_indices = inject_with_index([]){|acc,e,i| acc << i if e < i }
>   array.delete_at( remove_indices )
> 
>  and finally the 1.9 possibility,
> 
>   array.map_with_index!{ |e,i| e < i ? nil : e }.compact!
> 
>  before compromising with
> 
>   array = (0...array.size).zip(array).map{ |i,e| e < i ? nil : e }.compact
> 
>  Anything more elegant available?
> 
>  Or perhaps an alternative way to attack the problem?

irb(main):010:0>  a = %w{foo bar baz}
=>  ["foo", "bar", "baz"]
irb(main):011:0>  current = 1
=>  1
irb(main):012:0>  a.slice! 0...current
=>  ["foo"]
irb(main):013:0>  a
=>  ["bar", "baz"]

Kind regards

robert


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