A regexp for an include? method

ruby-talk
1

Hi,

I want to see if a certain pattern is inside an array. I tried:
myArray.flatten.include?(/myPattern/)

but it always return false. Why? Is it because the "include?" doesn't takes
regular expressions?
Here's another example that I tried inside an irb session:

data = ["TC_TP1", "TC_TP2", "TC_TP3"]
=>["TC_TP1", "TC_TP2", "TC_TP3"]
data.include?(/TC_TP/)
=> false
data.include?(/TC_TP.*/)
=> false
data.include?(/TC_TP1/)
=> false
data.include?("TC_TP1")
=> true !!!

Thanks for your help.

2

It's because include? uses #eql? or == for comparison while regexp matching is done via === and =~. You can use #find, #select or #any?

irb(main):042:0> data.find {|x| /TC_TP/ =~ x}
=> "TC_TP1"
irb(main):043:0> data.find {|x| /XTC_TP/ =~ x}
=> nil
irb(main):044:0> data.select {|x| /XTC_TP/ =~ x}
=>
irb(main):045:0> data.select {|x| /TC_TP/ =~ x}
=> ["TC_TP1", "TC_TP2", "TC_TP3"]
irb(main):046:0> data.any? {|x| /TC_TP/ =~ x}
=> true
irb(main):047:0> data.any? {|x| /YTC_TP/ =~ x}
=> false

I'd go for any? as it short circuits, i.e. terminates after the first successful match.

Kind regards

    robert

···

Boucher, Eric <eric.boucher@messier-dowty.com> wrote:

Hi,

I want to see if a certain pattern is inside an array. I tried:
myArray.flatten.include?(/myPattern/)

but it always return false. Why? Is it because the "include?" doesn't
takes regular expressions?
Here's another example that I tried inside an irb session:

data = ["TC_TP1", "TC_TP2", "TC_TP3"]
=>["TC_TP1", "TC_TP2", "TC_TP3"]
data.include?(/TC_TP/)
=> false
data.include?(/TC_TP.*/)
=> false
data.include?(/TC_TP1/)
=> false
data.include?("TC_TP1")
=> true !!!

Thanks for your help.

3

Hi,

I want to see if a certain pattern is inside an array. I tried:
myArray.flatten.include?(/myPattern/)

but it always return false. Why? Is it because the "include?" doesn't takes
regular expressions?
Here's another example that I tried inside an irb session:

data = ["TC_TP1", "TC_TP2", "TC_TP3"]
=>["TC_TP1", "TC_TP2", "TC_TP3"]
data.include?(/TC_TP/)
=> false
data.include?(/TC_TP.*/)
=> false
data.include?(/TC_TP1/)
=> false
data.include?("TC_TP1")
=> true !!!

You can use grep() for this:

>> data = ["TC_TP1", "TC_TP2", "TC_TP3"]
=> ["TC_TP1", "TC_TP2", "TC_TP3"]
>> data.grep(/TC_TP/)
=> ["TC_TP1", "TC_TP2", "TC_TP3"]
>> !data.grep(/TC_TP/).empty?
=> true

Hope that gives you some fresh ideas.

James Edward Gray II

···

On Feb 22, 2006, at 6:52 AM, Boucher, Eric wrote:

4

Boucher, Eric wrote:

Hi,

I want to see if a certain pattern is inside an array. I tried:
myArray.flatten.include?(/myPattern/)

but it always return false. Why? Is it because the "include?" doesn't takes
regular expressions?
Here's another example that I tried inside an irb session:

data = ["TC_TP1", "TC_TP2", "TC_TP3"]
=>["TC_TP1", "TC_TP2", "TC_TP3"]
data.include?(/TC_TP/)
=> false
data.include?(/TC_TP.*/)
=> false
data.include?(/TC_TP1/)
=> false
data.include?("TC_TP1")
=> true !!!

Thanks for your help.

myArray.flatten.grep(/myPattern/)

5

What about using:
data.match(/TC_TP/)
should return nil if it doesn't match, otherwise returns the matching
string.

6

semmons99@gmail.com wrote:

What about using:
data.match(/TC_TP/)
should return nil if it doesn't match, otherwise returns the matching
string.

It doesn't return the matching string but an object of type MatchData. The matched string can be extracted from that. Another form is to use String# with regexp, like

arr.any? {|s| s[/TC_TP/]}

Kind regards

    robert