Simple gsub question \' \` what?

Ruby
1

Sorry for the simple question, I just can’t figure this out after a
couple hours…

I need to parse a string:

string = column-1:block-0,block-2,block-1,block-3

and I need to extract everything before the : (colon) into one variable
(should end up like this:
string1 = column-1

and then the rest of the string (block-0,block-2,block-1,block3) into an
array…

How can I use gsub to extract everything before the colon?

I’ve looked at the documentation and just can’t understand how to use
the ` or ' syntax… I want the two new strings to be:

string1 = column-1
string2 = [“block-0”, “block-2”, “block-1”, “block-3”]

I’m thinking it’s something like this:

string.gsub(/:/, “`”)

really, I just don’t get it…

the documentation that I’m looking at is here:
http://dev.rubycentral.com/ref/ref_c_string.html

thanks a bunch!
-Dustin

2

Alle venerdì 30 marzo 2007, Dustin A. ha scritto:

-Dustin

I don’t think you need gsub here. gsub is used to replace parts of a
string
with other characters. What you need is a regexp. This should work:

string.match( /^([^:]):(.)$/ )
string1=$1
string2=$2.split(’,’)

The regexp will put anything from the beginning of the string until the
first : (excluded) in the global variable $1 and anything after the : in
the
variable $2. You can then convert $2 to an array of string using the
String#split method.

I hope this helps

Stefano

3

Hello,

you could just use split:

split = string.split(’:’)
string1 = split[0]
string2 = split[1].split(’,’)

– Kristoffer

4

Dustin A. wrote:

and then the rest of the string (block-0,block-2,block-1,block3) into an
array…

I’d use two calls to split:

irb(main):001:0> string = ‘column-1:block-0,block-2,block-1,block-3’
=> “column-1:block-0,block-2,block-1,block-3”
irb(main):002:0> string1, s = string.split(’:’)
=> [“column-1”, “block-0,block-2,block-1,block-3”]
irb(main):003:0> string1
=> “column-1”
irb(main):004:0> string2 = s.split(’,’)
=> [“block-0”, “block-2”, “block-1”, “block-3”]
irb(main):005:0>

You could probably turn that into a one-liner but that’s just golfing.

5

On Mar 30, 2007, at 5:39 PM, Timothy H. wrote:

(should end up like this:
irb(main):002:0> string1, s = string.split(‘:’)
=> [“column-1”, “block-0,block-2,block-1,block-3”]
irb(main):003:0> string1
=> “column-1”
irb(main):004:0> string2 = s.split(‘,’)
=> [“block-0”, “block-2”, “block-1”, “block-3”]
irb(main):005:0>

You could probably turn that into a one-liner but that’s just golfing.

Here’s a bit of “live” code that does the same thing (plus .to_f on
the elements before turning them into a Vector, but you can knock
that part out yourself)

def add line
id, vals = line.split(/:\s*/, 2)
@labels << id
@data << Vector[*(vals.split(‘,’).map {|v| v.to_f})]
end

Note that the second arg (2) to split is important if a ‘:’ can occur
anywhere in your block-N parts. Of course, you just need vals.split
(‘,’)

-Rob

Rob B. http://agileconsultingllc.com
[email protected]