[Note: parts of this message were removed to make it a legal post.]

Hello,

I'm wondering if there is a method for the String class that splits a string on some characters and keeps the split characters in the elements of the resulting array?

The split method returns an array in this example:

p "This is a sentence. This is a sentence! This is a sentence?".strip.split(/\.|\?|\!/)


["This is a sentence", " This is a sentence", " This is a sentence"]

The three sentences in the above string have very different meanings, but loose those meanings without the punctuation, so I'd like to keep the punctuation. I'd like a method that keeps the split characters, and returns this array:

["This is a sentence.", " This is a sentence!", " This is a sentence?"]

Does such an array exist? If not, would it be possible to modify the split method to produce that result?

I'm running Ruby 1.8.6 on Windows.

Thanks for your .

> Does such an array exist? If not, would it be possible to modify the split method to produce that result?

If you put the pattern in a group, it will be included in the array --
but not quite in the way you described:

irb(main):001:0> p "This is a sentence. This is a sentence! This is a
sentence?".strip.split(/(\.|\?|\!)/)
["This is a sentence", ".", " This is a sentence", "!", " This is a
sentence", "?"]

Regards,
Thomas.

2008/2/25, Glenn <glenn_ritz@yahoo.com>:
> Hello,
>
> I'm wondering if there is a method for the String class that splits a string on some characters and keeps the split characters in the elements of the resulting array?
>
> The split method returns an array in this example:
>
> p "This is a sentence. This is a sentence! This is a sentence?".strip.split(/\.|\?|\!/)
>
>
> ["This is a sentence", " This is a sentence", " This is a sentence"]
>
> The three sentences in the above string have very different meanings, but loose those meanings without the punctuation, so I'd like to keep the punctuation. I'd like a method that keeps the split characters, and returns this array:
>
> ["This is a sentence.", " This is a sentence!", " This is a sentence?"]
>
> Does such an array exist? If not, would it be possible to modify the split method to produce that result?
>
> I'm running Ruby 1.8.6 on Windows.

Hm, you could do it with lookbehind on 1.9. On 1.8 you only have
lookforward which gives you this:

irb(main):002:0> "a. b.".split /(?=\.\s+)/
=> ["a", ". b."]

Not quite what you wanted. :-)

But here's an alternative approach which works with 1.8:

irb(main):005:0> "a. b. c! d? e.".scan /.*?[.!?](?:\s|$)/
=> ["a. ", "b. ", "c! ", "d? ", "e."]

Kind regards

robert

--
use.inject do |as, often| as.you_can - without end

On Feb 25, 2008, at 6:43 AM, Robert Klemme wrote:

> 2008/2/25, Glenn <glenn_ritz@yahoo.com>:
>> Hello,
>>
>> I'm wondering if there is a method for the String class that splits
>> a string on some characters and keeps the split characters in the
>> elements of the resulting array?
>>
>> The split method returns an array in this example:
>>
>> p "This is a sentence. This is a sentence! This is a
>> sentence?".strip.split(/\.|\?|\!/)
>>
>>
>> ["This is a sentence", " This is a sentence", " This is a sentence"]
>>
>> The three sentences in the above string have very different
>> meanings, but loose those meanings without the punctuation, so I'd
>> like to keep the punctuation. I'd like a method that keeps the
>> split characters, and returns this array:
>>
>> ["This is a sentence.", " This is a sentence!", " This is a
>> sentence?"]
>>
>> Does such an array exist? If not, would it be possible to modify
>> the split method to produce that result?
>>
>> I'm running Ruby 1.8.6 on Windows.
>
> Hm, you could do it with lookbehind on 1.9. On 1.8 you only have
> lookforward which gives you this:
>
> irb(main):002:0> "a. b.".split /(?=\.\s+)/
> => ["a", ". b."]
>
> Not quite what you wanted. :-)

We can turn look-ahead into into look-behind, though it's not pretty:

$ ruby -ve 'p "This is a sentence. This is a sentence! This is a
sentence?".reverse.split(/(?=(?:\A|\s+)[.!?])/).map { |s|
s.reverse }.reverse'
ruby 1.8.6 (2007-09-24 patchlevel 111) [i686-darwin9.1.0]
["This is a sentence. ", "This is a sentence! ", "This is a sentence?"]

James Edward Gray II