Extracting vowels and consonants using regular expression

[Dondi]

I am trying to parse a string and extract all vowels and consonants
into two separate substrings. However, I can't get my solution to
work. Any pointers are appreciated. Here is the approach I am using:

1) Extended the String Class with the following methods:

class String
def vowels
self.scan(/[aeiou]|(?![aeiou])y(?![aeiou])/i)
end

def consonants
self.scan(/![aeiou]|(?=[aeiou])y(?=[aeiou])/i)
end
end

2) Invoke the methods:

test_paragraph = "Mary had a little lamb"
@vowel_sub_str = test_paragraph.vowels
@consonant_sub_str = test_paragraph.consonants

However, the result is just two empty strings. I believe the problem
is in the regular expression, but I can't figure out just where. Any
ideas/pointers are appreciated.

Thanks.

 

[Stefano Crocco]

Alle Saturday 02 February 2008, Dondi ha scritto:

I am trying to parse a string and extract all vowels and consonants
into two separate substrings. However, I can't get my solution to
work. Any pointers are appreciated. Here is the approach I am using:

1) Extended the String Class with the following methods:

class String
def vowels
self.scan(/[aeiou]|(?![aeiou])y(?![aeiou])/i)
end

def consonants
self.scan(/![aeiou]|(?=[aeiou])y(?=[aeiou])/i)
end
end

2) Invoke the methods:

test_paragraph = "Mary had a little lamb"
@vowel_sub_str = test_paragraph.vowels
@consonant_sub_str = test_paragraph.consonants

However, the result is just two empty strings. I believe the problem
is in the regular expression, but I can't figure out just where. Any
ideas/pointers are appreciated.

Thanks.

A simple (but I fear not too efficient) way is:

class String

def vowels
gsub(/[^aeiou]/, '')
end

def consonants
gsub(/[aeiou]/, '')
end

end

Stefano

 

[Robert Dober]

A simple (but I fear not too efficient) way is:

Not sure if OP excluded non letters from the input

class String

def vowels
gsub(/[^aeiou]/, '')
end

def consonants
gsub(/[aeiou]/, '')
end

end

Stefano

This shall do it in one run, quite complicated code, interested if
something more elegant can be found.
class String
def v_c
each_char.inject(["",""]){ |r, c|
case c
when /[aeiouy]/i
[r.first << c, r.last ]
when /[^a-z]/i
r
else
[r.first, r.last << c ]
end
}
end
end

HTH
Robert

 

[Corey Haines]

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

Elegant? I don't know, but I kind of like it.

"corey".split(//).partition { |x| "aeiouAEIOU"[x] }

returns

=> [["o", "e"], ["c", "r", "y"]]

irb(main):006:0> "corey haines".split(//).partition { |x| "aeiouAEIOU"[x] }
=> [["o", "e", "a", "i", "e"], ["c", "r", "y", " ", "h", "n", "s"]]

you might want to skip spaces


-Corey

A simple (but I fear not too efficient) way is:

Not sure if OP excluded non letters from the input

class String

def vowels
gsub(/[^aeiou]/, '')
end

def consonants
gsub(/[aeiou]/, '')
end

end

Stefano

This shall do it in one run, quite complicated code, interested if
something more elegant can be found.
class String
def v_c
each_char.inject(["",""]){ |r, c|
case c
when /[aeiouy]/i
[r.first << c, r.last ]
when /[^a-z]/i
r
else
[r.first, r.last << c ]
end
}
end
end

HTH
Robert

 

[Robert Dober]

Elegant? I don't know, but I kind of like it.

"corey".split(//).partition { |x| "aeiouAEIOU"[x] }

returns

=> [["o", "e"], ["c", "r", "y"]]

irb(main):006:0> "corey haines".split(//).partition { |x| "aeiouAEIOU"[x] }
=> [["o", "e", "a", "i", "e"], ["c", "r", "y", " ", "h", "n", "s"]]

you might want to skip spaces


-Corey

Excellent Corey, allow me to make it fit *any* string, I still have
not seen any statement that we are treating letters only

"cor4ey ha2ines".scan(/[a-z]/i).join.each_char.partition { |x| "aeiouAEIOU"[x] }

Robert

 

[Robert Dober]

"cor4ey ha2ines".scan(/[a-z]/i).join.each_char.partition { |x| "aeiouAEIOU"[x] }

and some golfing

{ |x| /[aeiou]/i =~ x }

R.

 

[Corey Haines]

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

Sweet! I like pulling the numbers out, but I get this in irb

irb(main):001:0> "cor4ey ha2ines".scan(/[a-z]/i).join.each_char.partition {
|x| "aeiouAEIOU"[x] }
NoMethodError: undefined method `each_char' for "coreyhaines":String

Why not use split(//) instead of each_char?

Elegant? I don't know, but I kind of like it.

"corey".split(//).partition { |x| "aeiouAEIOU"[x] }

returns

=> [["o", "e"], ["c", "r", "y"]]

irb(main):006:0> "corey haines".split(//).partition { |x| "aeiouAEIOU"[x] }
=> [["o", "e", "a", "i", "e"], ["c", "r", "y", " ", "h", "n", "s"]]

you might want to skip spaces


-Corey

Excellent Corey, allow me to make it fit *any* string, I still have
not seen any statement that we are treating letters only

"cor4ey ha2ines".scan(/[a-z]/i).join.each_char.partition { |x|
"aeiouAEIOU"[x] }

Robert

 

[Corey Haines]

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

Cool. I wasn't sure exactly how to do that. Now I do! And, in the words
of one of my personal favorite philosophers, "Knowing is half the battle."

"cor4ey ha2ines".scan(/[a-z]/i).join.each_char.partition { |x|

"aeiouAEIOU"[x] }
and some golfing

{ |x| /[aeiou]/i =~ x }

R.

 

[Robert Dober]

Oh sorry using 1.9 excluseviley now...
Robert

 

[Corey Haines]

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

Okay. Sounds good. I'm still on 1.8.

Thanks for the ideas.

-Corey