Hi, Rubyists.
What is the best way of attacking field split on ';' when the string looks
like:
s = 'a;b;c\;;d;'
s.split(/???;/)
=> ["a", "b", "c\;", "d"]
Or is it best to use s.each_byte and do it by hand?
--
-mark. (probertm @ acm dot org)
How about something ala
irb(main):015:0> "aa;bbb\\;;abc;;d\\\\;e;".scan(/(?:\\[^.]|[^;])*;/)
=> ["aa;", "bbb\\;;", "abc;", ";", "d\\\\;", "e;"]
On Thursday 30 September 2004 23:15, Mark Probert wrote:
Hi, Rubyists.
What is the best way of attacking field split on ';' when the string looks
like:s = 'a;b;c\;;d;'
s.split(/???;/)
=> ["a", "b", "c\;", "d"]Or is it best to use s.each_byte and do it by hand?
--
Simon Strandgaard
Mark Probert wrote:
Hi, Rubyists.
What is the best way of attacking field split on ';' when the string looks like:
s = 'a;b;c\;;d;'
s.split(/???;/)
=> ["a", "b", "c\;", "d"]Or is it best to use s.each_byte and do it by hand?
Normally this would call for fixed width lookbehind,
/(?<!\\);/
but as far as I know its not included in the ruby regexp engine.
But for further clarification:
How should 'a;b\\;;c' be split?
If backslashs can be escaped (and you'd want that because otherwise you can't have a field "b\" its more difficult.
And maybe the CSV library can help you here.
regards,
Brian
--
Brian Schröder
http://ruby.brian-schroeder.de/
Mark Probert wrote:
Hi, Rubyists.
Moin!
What is the best way of attacking field split on ';' when the string looks like:
s = 'a;b;c\;;d;'
s.split(/???;/)
=> ["a", "b", "c\;", "d"]Or is it best to use s.each_byte and do it by hand?
This works, (even with escaped escape characters) but you might be better off doing it by hand to keep complexity low:
irb(main):025:0> str = "hello;world;foo\\;bar;no escape\\\\;blar"; puts str hello;world;foo\;bar;no escape\\;blar => nil irb(main):026:0> str.scan(/(?:(?!\\).(?:\\{2})*\\;|[^;])+/).map { |str| str.gsub(/\\(.)/, '\1') }
=> ["hello", "world", "foo;bar", "no escape\\", "blar"]
Regards,
Florian Gross
maybe this one is better ?
irb(main):001:0> "aa;bbb\\;;abc;;d\\\\;e;f".scan(/(?:\A|;)((?:\\[^.]|[^;])*)/)
{ p $1 }
"aa"
"bbb\\;"
"abc"
""
"d\\\\"
"e"
"f"
=> "aa;bbb\\;;abc;;d\\\\;e;f"
irb(main):002:0>
On Thursday 30 September 2004 23:29, Simon Strandgaard wrote:
On Thursday 30 September 2004 23:15, Mark Probert wrote:
> Hi, Rubyists.
>
> What is the best way of attacking field split on ';' when the string
> looks like:
>
> s = 'a;b;c\;;d;'
> s.split(/???;/)
> => ["a", "b", "c\;", "d"]
>
> Or is it best to use s.each_byte and do it by hand?How about something ala
irb(main):015:0> "aa;bbb\\;;abc;;d\\\\;e;".scan(/(?:\\[^.]|[^;])*;/)
=> ["aa;", "bbb\\;;", "abc;", ";", "d\\\\;", "e;"]
--
Simon Strandgaard
Hi ..
How about something ala
irb(main):015:0> "aa;bbb\\;;abc;;d\\\\;e;".scan(/(?:\\[^.]|[^;])*;/)
=> ["aa;", "bbb\\;;", "abc;", ";", "d\\\\;", "e;"]
Thanks! That is close enough:
irb(main):019:0> s.scan(/(?:\\[^.]|[^;])*/).each do |it|
irb(main):020:1* next if it.empty?
irb(main):021:1> puts " --> #{it}"
irb(main):022:1> end
--> a is a word
--> b is too
--> c\; for fun
--> d -- forget it
=> ["a is a word", "", "b is too", "", "c\\; for fun", "", "d -- forget
it", "", ""]
Simon Strandgaard <neoneye@adslhome.dk> wrote:
--
-mark. (probertm @ acm dot org)
But for further clarification:
How should 'a;b\\;;c' be split?
Guess is that it should be
["a", "b\", nil, "c"]
characters escaped by backslash at semi-colon, colon and backslash i.e.
; => \; : => \: \ => \\
If backslashs can be escaped (and you'd want that because otherwise you
can't have a field "b\" its more difficult.And maybe the CSV library can help you here.
thanks,
Dany
> But for further clarification:
> How should 'a;b\\;;c' be split?
Guess is that it should be
["a", "b\", nil, "c"]
Sorry... I meant
["a", "b\\", nil, "c"] where b\\ would utimately become b\ when the escape chars are process in the data portion
characters escaped by backslash at semi-colon, colon and backslash i.e.
; => \; : => \: \ => \\
> If backslashs can be escaped (and you'd want that because otherwise you
> can't have a field "b\" its more difficult.
>
Didn't think about that one... I thought this was simple and the problem was my lack of programming experience...
Dany
On Thu, 30 Sep 2004 17:57:19 -0400 Dany Cayouette <danyc@nortelnetworks.com> wrote:
"Mark Probert" <probertm@nospam-acm.org> schrieb im Newsbeitrag
news:Xns95749654816D0probertmnospamtelusn@198.161.157.145...
Hi ..
>
> How about something ala
>
> irb(main):015:0> "aa;bbb\\;;abc;;d\\\\;e;".scan(/(?:\\[^.]|[^;])*;/)
> => ["aa;", "bbb\\;;", "abc;", ";", "d\\\\;", "e;"]
>Thanks! That is close enough:
irb(main):019:0> s.scan(/(?:\\[^.]|[^;])*/).each do |it|
irb(main):020:1* next if it.empty?
irb(main):021:1> puts " --> #{it}"
irb(main):022:1> end
--> a is a word
--> b is too
--> c\; for fun
--> d -- forget it
=> ["a is a word", "", "b is too", "", "c\\; for fun", "", "d -- forget
it", "", ""]
s = "aa;bbb\\;;abc;;d\\\\;e;"
=> "aa;bbb\\;;abc;;d\\\\;e;"
s.scan /(?:\\.|[^\\;])+/
=> ["aa", "bbb\\;", "abc", "d\\\\", "e"]
Regards
robert
Simon Strandgaard <neoneye@adslhome.dk> wrote:
[snip]
>> s = "aa;bbb\\;;abc;;d\\\\;e;"
=> "aa;bbb\\;;abc;;d\\\\;e;"
>> s.scan /(?:\\.|[^\\;])+/
=> ["aa", "bbb\\;", "abc", "d\\\\", "e"]
If its a csv file.. shouldn't output then be?
["aa", "bbb\\;", "abc", "", "d\\\\", "e", ""]
On Friday 01 October 2004 09:45, Robert Klemme wrote:
--
Simon Strandgaard
"Simon Strandgaard" <neoneye@adslhome.dk> schrieb im Newsbeitrag news:200410012022.59526.neoneye@adslhome.dk...
On Friday 01 October 2004 09:45, Robert Klemme wrote:
[snip]>> s = "aa;bbb\\;;abc;;d\\\\;e;"
=> "aa;bbb\\;;abc;;d\\\\;e;"
>> s.scan /(?:\\.|[^\\;])+/
=> ["aa", "bbb\\;", "abc", "d\\\\", "e"]If its a csv file.. shouldn't output then be?
["aa", "bbb\\;", "abc", "", "d\\\\", "e", ""]
Darn! You're right. Unfortunately using "*" instead of "+" is not sufficient: far too many empty strings are found that way.
robert