i’m experiencing with regexp and ruby and follo the page
http://www.rubycentral.com/book/ref_c_regexp.html
at “===” i’ve found an example :
a = “HELLO”
case a
when /^a-z*$/; print “Lower case\n”
when /^A-Z*$/; print “Upper case\n”
else; print “Mixed case\n”
end
saying it produces :
=> Upper case
i got :
Mixed case
why this discrapency, if any ???
is that due to the fact my script file is UTF-8 encoded ???
also with :
truc = ‘toto’
rgx=Regexp.new(‘^toto$’)
flag=(truc =~ rgx)? true : false
p “flag = #{flag}”
=> “flag = true”
flag=(truc === rgx) /// this one i don’t understand the result
p “flag = #{flag}”
=> “flag = false”
flag=(truc == rgx)
p “flag = #{flag}”
=> “flag = false”
flag=(truc =~ rgx)
p “flag = #{flag}”
=> “flag = 0”
why, when aString = ‘toto’ and ARegexp = Regexp.new(‘^toto$’)
the equality “===” returns false ???
Ross B. wrote:
On Thu, 2006-03-23 at 23:13 +0900, Une bévue wrote:
the equality “===” returns false ???
Adding to Ross’ excellent explanation: it helps to not view “===” as
an equality operator. Rather it’s a general matching operator, whatever
matching means in a certain context. For RX it will do an RX match, for
class objects it will do the kind_of? check, for a range it will check
include? etc. Btw, has anyone an idea why this does not apply to
Enumerable?
[1,2,3].include? 2
=> true
[1,2,3] === 2
=> false
Kind regards
robert
On Thu, 2006-03-23 at 23:13 +0900, Une bévue wrote:
end
saying it produces :
=> Upper case
i got :
Mixed case
why this discrapency, if any ???
I guess that’s a typo on the site, it’s correct in my printed 2nd ed:
a = “HELLO”
case a
when /^[a-z]$/; print “Lower case\n”
when /^[A-Z]$/; print “Upper case\n”
else; print “Mixed case\n”
end
-> Upper Case
(Notice the [] brackets that denote a character set)
p “flag = #{flag}”
=> “flag = false”
flag=(truc =~ rgx)
p “flag = #{flag}”
=> “flag = 0”
why, when aString = ‘toto’ and ARegexp = Regexp.new(’^toto$’)
the equality “===” returns false ???
Try this:
truc = ‘toto’
rgx=Regexp.new(’^toto$’)
flag=(truc =~ rgx)? true : false
p “flag = #{flag}”
=> “flag = true”
flag=(rgx === truc) # /// switch these around
p “flag = #{flag}”
=> “flag = true”
flag=(truc == rgx)
p “flag = #{flag}”
# => “flag = false”
flag=(truc =~ rgx)
p “flag = #{flag}”
# => “flag = 0”
See also the ‘what on earth…’ thread that’s been on the list recently
(yesterday/today I think).
Robert K. wrote:
Enumerable?
[1,2,3].include? 2
=> true
[1,2,3] === 2
=> false
It would be nice, but then how would this work:
irb(main):001:0> case [1,2,3]
irb(main):002:1> when [1,2,3]
irb(main):003:1> puts “same array!”
irb(main):004:1> end
same array!
=> nil
Ross B. [email protected] wrote:
(Notice the [] brackets that denote a character set)
fine, thanks, difficult to catch out typos particularly in regexps…
Try this:
[…]
flag=(rgx === truc) # /// switch these around
p “flag = #{flag}”
=> “flag = true”
i did both :
flag=(truc === rgx)
p “flag = #{flag} for flag=(truc === rgx)”
=> “flag = false for flag=(truc === rgx)”"
flag=(rgx === truc)
p “flag = #{flag} for flag=(rgx === truc)”
=> “flag = true for flag=(rgx === truc)”
that’s a really strange behaviour, to me, of ruby, a “symetrical”
operator symbol being not commutative ???
better to know 
See also the ‘what on earth…’ thread that’s been on the list recently
(yesterday/today I think).
ok, thanks very much !
I’m trying to use builder to construct jnlp files. I need to create
elements with “-” in the name and can’t. For example I need to output
the following xml fragment:
Here’s what I tried with builder:
x = Builder::XmlMarkup.new(:target => $stdout, :indent => 1)
x.security {
x.all-permissions
}
but the “-” is parsed in the name and this produces a NameError
NameError: undefined local variable or method `permissions’ for
main:Object
Is there a way to do this?
Robert K. wrote:
Enumerable?
[1,2,3].include? 2
=> true
[1,2,3] === 2
=> false
It would be nice, but then how would this work:
irb(main):001:0> case [1,2,3]
irb(main):002:1> when [1,2,3]
irb(main):003:1> puts “same array!”
irb(main):004:1> end
same array!
=> nil
YANAGAWA Kazuhisa wrote:
prints “foo”
Good point! Thanks to you and Joel!
Kind regards
robert
In Message-Id: [email protected]
Robert K. [email protected] writes:
[1,2,3].include? 2
=> true
[1,2,3] === 2
=> false
Once that can be but “fixed” later since… it can be a seed of
confusion and we can use “*” for array on when clause.
n = 2
array = [2, 4, 6]
case n
when *array
puts “foo”
else
puts “bar”
end
prints “foo”