Wrapped String#gsub

Ruby Development
1

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$ cat test2.rb
class String
def wrap_gsub(*a, &b)
self.gsub(*a, &b)
puts “in wrapper ? #{$&}”
end
end

puts “wrapper”
“abc”.wrap_gsub(/([abc]+)/n) {|x| p $&}
puts “and out of wrapper - #{$&}”
puts “=======”
puts “original”
“abc”.gsub(/([abc]+)/n) {|x| p $&}

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$ ruby test2.rb
wrapper
nil
in wrapper ? abc
and out of wrapper -

original
“abc”
$ ruby --version
ruby 1.9.0 (2008-01-22 revision 0) [i686-linux]
mithrandir@losrorien ~/Development/ruby-1.8.6 $ ruby18 test2.rb
wrapper
nil
in wrapper ? abc
and out of wrapper -

original
“abc”
$ ruby18 --version
ruby 1.8.6 (2007-12-03 patchlevel 113) [i686-linux]

2

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Park Ji-In wrote:

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$ cat test2.rb
class String
def wrap_gsub(*a, &b)
self.gsub(*a, &b)
puts “in wrapper ? #{$&}” # <= e$B$3$l$N7k2L$G$"$ke(B nil e$B$,JV$j$^$9e(B
end
end

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$ cat test2.rb
class String
def wrap_gsub(*a, &b)
self.gsub(*a, &b)
puts “in wrapper ? #{$&}”
self
end
end

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3

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class String
def wrap_gsub(*a, &b)
self.gsub(*a, &b)
end
end

puts “wrapper”
“abc,abc”.wrap_gsub(/([abc]+)/) { puts $1 }
puts “original”
“abc,abc”.gsub(/([abc]+)/) { puts $1 }

– e$B7k2Le(B –

wrapper
nil
nil
original
“abc”
“abc”

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4

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Park Ji-In wrote:

original
“abc”
“abc”

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class String
def wrap_gsub(a)
self.gsub(a){ yield $1}
end
end

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class String
def wrap_gsub(*a)
self.gsub(*a)
end
end

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5

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#!/usr/bin/ruby
class String
def wrap_gsub(re, &b)
self=~re # =>
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self.gsub(re, &b)
end
end

“abc,abc”=~/([a]+)/
“abc,abc”.wrap_gsub(/([abc]+)/) { puts $1 } # =>
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~$ ruby -v test.rb
ruby 1.8.6 (2007-06-07 patchlevel 36) [i486-linux]
a
a

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#!/usr/bin/ruby
class String
def wrap_gsub2(*a)
self.gsub(*a){yield($~) if block_given?}
end
end

“abc,abc”.wrap_gsub2(/(a)(bc)/) {|m| puts m[0], m[1], m[2] }

---- e$B=PNOe(B
$ ruby -v test.rb
ruby 1.8.6 (2007-06-07 patchlevel 36) [i486-linux]
abc
a
bc
abc
a
bc

Park Ji-In e$B$5$s$O=q$-$^$7$?e(B:

6

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2008/1/26, KURODA Hiraku [email protected]:

“abc,abc”.wrap_gsub2(/(a)(bc)/) {|m| puts m[0], m[1], m[2] }

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DelegateClasse$B$bF1$87k2L$,$G$^$7$?!#e(B

require ‘delegate’

class Merong < DelegateClass(String)
def initialize(str)
@mystr = str
super(@mystr)
end
end

m = Merong.new(‘abc’)
s = m.gsub(/([abc]+)/) {$1.upcase}
puts s

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(eval):3:in __send__': undefined method upcase’ for nil:NilClass
(NoMethodError)
from (eval):3:in `gsub’
from delegate_test.rb:11

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