Probably a stupid question, but is there a way to use :gsub replacement
without $0 $1 $2 $3 (and without "\0\1\2\3")?
I would prefer something like:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
p [name, family]
# instead of this
p [$1, $2]
end
--
Posted via http://www.ruby-forum.com/.
is it a requirement that you use gsub?
irb(main):008:0> name, family = "John Smith".split
=> ["John", "Smith"]
irb(main):009:0> p [name, family]
["John", "Smith"]
=> nil
On Fri, 2011-04-08 at 00:25 +0900, Alexey Petrushin wrote:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
p [name, family]# instead of this
p [$1, $2]
end
Alexey Petrushin wrote in post #991484:
Probably a stupid question, but is there a way to use :gsub replacement
without $0 $1 $2 $3 (and without "\0\1\2\3")?
There is also $~ (Regexp.last_match); $1/$2/etc are just a facade.
I would prefer something like:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
p [name, family]# instead of this
p [$1, $2]
end
"John Smith".gsub /(.+)\s(.+)/ do
name, family = $~.captures
p [name, family]
end
Not pretty, but you can wrap it up in your own method:
class String
def gsubcap(*arg)
gsub(*arg) { yield $~.captures }
end
end
"John Smith".gsubcap /(.+)\s(.+)/ do |name, family|
p [name, family]
end
--
Posted via http://www.ruby-forum.com/\.
Or if you are a ruby 1.9 user, you could use named capture groups
instead. I'm not sure they make the regexp itself any clearer in this
case though:
"John Smith".gsub /(?<name>.+)\s(?<family>.+)/ do
p [$~[:name],$~[:family]]
end
--
Posted via http://www.ruby-forum.com/.
Alexey Petrushin wrote in post #991484:
Probably a stupid question, but is there a way to use :gsub replacement
without $0 $1 $2 $3 (and without "\0\1\2\3")?
Where are you replacing anything?
I would prefer something like:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
p [name, family]# instead of this
p [$1, $2]
end
"John Smith".scan(/\S+/) do |match|
puts match
end
--output:--
John
Smith
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Alexey Petrushin wrote in post #991484:
I would prefer something like:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
p [name, family]# instead of this
p [$1, $2]
end
i also wonder if gsub is necessary... there's no replacement here as
far as i can tell. my oversimplified monkey brain comes up with this:
irb(main):001:0> str = "John Smith - Minister of Funny Walks."
=> "John Smith - Minister of Funny Walks."
irb(main):002:0> arr = str.split(" ")
=> ["John", "Smith", "-", "Minister", "of", "Funny", "Walks."]
irb(main):003:0> name, family = arr[0], arr[1]
=> ["John", "Smith"]
irb(main):004:0> puts name
John
=> nil
irb(main):005:0> puts family
Smith
=> nil
this also makes some assumptions about the data, of course...
-j
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Thanks for advices, I didn't know about $~ containting arrays of
results, add new 'substitute' method is probably the best solution.
This solution is not very generalizable. It only works as presented for
cases where all the stuff you want to discard looks the same.
No, it's no less generalizable than $X stuff, use splats if You have
different matches.
"John Smith".substitute{|*tokens| ...}
And yes the provided sample is unclear, there where actually no
replacement, maybe it should be something like that:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
"#{name[0..0]}. #{family}"
end
Here's the complete solution:
class String
def substitute(*args)
gsub(*args){yield Regexp.last_match.captures}
end
def substitute!(*args)
gsub!(*args){yield Regexp.last_match.captures}
end
end
Thanks for help!
--
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This solution is not very generalizable. It only works as presented for
cases where all the stuff you want to discard looks the same. I wouldn't
want to have to deal with this kind of thing for a particularly complex
case:
str = 'John Smith: A Good Man -- A Good Husband. RIP (1976)'.split
first, *remainder = str.split
last, *non_name = remainder.split(': ')
desc1, *the_rest = non_name.split(' -- ')
desc2, *deceased = the_rest.split('. ')
. . . so, is there some way to use more descriptive variable names than
the default $1, $2, et cetera, for captures from within a regex? I'm not
aware of any, but I too would find that agreeable.
On Fri, Apr 08, 2011 at 12:36:23AM +0900, Reid Thompson wrote:
On Fri, 2011-04-08 at 00:25 +0900, Alexey Petrushin wrote:
> "John Smith".gsub /(.+)\s(.+)/ do |name, family|
> p [name, family]
>
> # instead of this
> p [$1, $2]
> end
is it a requirement that you use gsub?irb(main):008:0> name, family = "John Smith".split
=> ["John", "Smith"]
irb(main):009:0> p [name, family]
["John", "Smith"]
=> nil
--
Chad Perrin [ original content licensed OWL: http://owl.apotheon.org ]
Brian Candler wrote in post #991490:
Alexey Petrushin wrote in post #991484:
Probably a stupid question, but is there a way to use :gsub replacement
without $0 $1 $2 $3 (and without "\0\1\2\3")?There is also $~ (Regexp.last_match); $1/$2/etc are just a facade.
I would prefer something like:
"John Smith".gsub /(.+)\s(.+)/ do |name, family|
p [name, family]# instead of this
p [$1, $2]
end"John Smith".gsub /(.+)\s(.+)/ do
name, family = $~.captures
p [name, family]
end
And if you want to avoid writing code in perl:
str = "John Smith"
pattern = /(.+)\s(.+)/
result = str.gsub(pattern) do
md_obj = Regexp.last_match
first_name, last_name = md_obj[1], md_obj[2]
p first_name, last_name
end
Or to avoid any indexing, you could do this:
str = "John Smith"
pattern = /(.+)\s(.+)/
result = str.gsub(pattern) do |match|
first_name, last_name = match.split
p first_name, last_name
"some replacement"
end
puts result
--output:--
"John"
"Smith"
some replacement
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irb(main):001:0> "John;Smith".scan /\S+/ do |match|
irb(main):002:1* puts match
irb(main):003:1> end
John;Smith
=> "John;Smith"
Ups.
Better:
irb(main):04:0> "John;Smith".scan /\w+/ do |match|
irb(main):05:1* puts match
irb(main):06:1> end
John
Smith
The code still makes assumptions about the data, though: it is uniform
in that only the first n parts are the name, and not n[+|-]1.
On Thu, Apr 7, 2011 at 8:10 PM, 7stud -- <bbxx789_05ss@yahoo.com> wrote:
"John Smith".scan(/\S+/) do |match|
puts match
end
--
Phillip Gawlowski
Though the folk I have met,
(Ah, how soon!) they forget
When I've moved on to some other place,
There may be one or two,
When I've played and passed through,
Who'll remember my song or my face.
name, family, = arr
On Apr 7, 11:57 pm, jake kaiden <jakekai...@yahoo.com> wrote:
irb(main):001:0> str = "John Smith - Minister of Funny Walks."
=> "John Smith - Minister of Funny Walks."
irb(main):002:0> arr = str.split(" ")
=> ["John", "Smith", "-", "Minister", "of", "Funny", "Walks."]
irb(main):003:0> name, family = arr[0], arr[1]
Chad Perrin wrote in post #991517:
. . . so, is there some way to use more descriptive variable names than
the default $1, $2, et cetera, for captures from within a regex? I'm
not
aware of any, but I too would find that agreeable.
Yes, ruby 1.9 has named capture groups. I posted an example earlier in
this thread.
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