Gsub not matching?

ruby-talk
1

Hi,

Can anyone see an obvious reason why
question.gsub!(/\{#{number_range}\}/, new_num) is not finding the
existing match in the question?

question = "A {30-45} year old {asthmatic, diabetic, hypertensive}
{male, .4} presents with blurry vision in the {left} eye. ... "

# Manage number range
if question.match(/\{ {0,5}([0-9][0-9]? {0,3}- {0,3}[0-9][0-9]?)
{0,5}\}/)
  number_range = question.match(/\{ {0,5}([0-9][0-9]? {0,3}-
{0,3}[0-9][0-9]?) {0,5}\}/)
  x1 = question.match(/\{ {0,5}([0-9][0-9]? {0,3}- {0,3}[0-9][0-9]?)
{0,5}\}/).to_s[1..-2].split('-')
  new_num = (rand(x1[0].to_i..x1[1].to_i)).to_s
  question.gsub!(/\{#{number_range}\}/, new_num)
end

when I "puts number_range" I get {30-45} so it should find the match.

PS any suggestions on refactoring the code would be welcome also as I am
learning on my own.

Thanks

Dave

···

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Posted via http://www.ruby-forum.com/.

2

I think it's the input, my value for number_range does not have the {...}:

question = "A {30-45} year old {asthmatic, diabetic, hypertensive} {male,
.4} presents with blurry vision in the {left} eye. ... "

number_range = '30-45'
new_num = '42'

puts question.gsub!(/\{#{number_range}\}/, new_num) => A 42 year old
{asthmatic, diabetic, hypertensive} {male, .4} presents with blurry vision
in the {left} eye. ...

3

How about:

question = "A {30-45} year old {asthmatic, diabetic, hypertensive}
{male, .4} presents with blurry vision in the {left} eye. ... "

if /\{\s*(\d+)\s*-\s*(\d+)\s*\}/ =~ question
  n1 = Integer($1)
  n2 = Integer($2)
  question[/\{\s*(\d+)\s*-\s*(\d+)\s*\}/] = "{#{rand(n1..n2)}}"

  puts question
end

or even

question = "A {30-45} year old {asthmatic, diabetic, hypertensive}
{male, .4} presents with blurry vision in the {left} eye. ... "

if /\{\s*(\d+)\s*-\s*(\d+)\s*\}/ =~ question
  n1 = Integer($1)
  n2 = Integer($2)
  question[/\{(\s*\d+\s*-\s*\d+\s*)\}/, 1] = rand(n1..n2).to_s

  puts question
end

Cheers

robert

···

On Tue, Feb 4, 2014 at 2:41 PM, Dave Castellano <lists@ruby-forum.com> wrote:

Hi,

Can anyone see an obvious reason why
question.gsub!(/\{#{number_range}\}/, new_num) is not finding the
existing match in the question?

question = "A {30-45} year old {asthmatic, diabetic, hypertensive}
{male, .4} presents with blurry vision in the {left} eye. ... "

# Manage number range
if question.match(/\{ {0,5}([0-9][0-9]? {0,3}- {0,3}[0-9][0-9]?)
{0,5}\}/)
  number_range = question.match(/\{ {0,5}([0-9][0-9]? {0,3}-
{0,3}[0-9][0-9]?) {0,5}\}/)
  x1 = question.match(/\{ {0,5}([0-9][0-9]? {0,3}- {0,3}[0-9][0-9]?)
{0,5}\}/).to_s[1..-2].split('-')
  new_num = (rand(x1[0].to_i..x1[1].to_i)).to_s
  question.gsub!(/\{#{number_range}\}/, new_num)
end

when I "puts number_range" I get {30-45} so it should find the match.

PS any suggestions on refactoring the code would be welcome also as I am
learning on my own.

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

4

Robert Klemme wrote in post #1135495:

or even

question = "A {30-45} year old {asthmatic, diabetic, hypertensive}
{male, .4} presents with blurry vision in the {left} eye. ... "

if /\{\s*(\d+)\s*-\s*(\d+)\s*\}/ =~ question
  n1 = Integer($1)
  n2 = Integer($2)
  question[/\{(\s*\d+\s*-\s*\d+\s*)\}/, 1] = rand(n1..n2).to_s

  puts question
end

Cheers

robert

Thank you! You have given me lots to look up and learn about from your
examples.

Dave

···

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5

Dave Castellano wrote in post #1135501:

Robert Klemme wrote in post #1135495:

if /\{\s*(\d+)\s*-\s*(\d+)\s*\}/ =~ question
  n1 = Integer($1)
  n2 = Integer($2)

Can you point me in the direction to look in order to understand the $1 and $2.

Are they variables inherent to regex?

···

Dave

--
Posted via http://www.ruby-forum.com/\.

6

Dear Dave,

Pattern matching sets some global variables :
$~ is equivalent to ::last_match;
$& contains the complete matched text;
$` contains string before match;
$' contains string after match;
$1, $2 and so on contain text matching first, second, etc capture group;
$+ contains last capture group.

Abinoam Jr.

···

From: Class: Regexp (Ruby 2.1.0)

On Tue, Feb 4, 2014 at 9:30 PM, Dave Castellano <lists@ruby-forum.com> wrote:

Dave Castellano wrote in post #1135501:

Robert Klemme wrote in post #1135495:

if /\{\s*(\d+)\s*-\s*(\d+)\s*\}/ =~ question
  n1 = Integer($1)
  n2 = Integer($2)

Can you point me in the direction to look in order to understand the $1 and $2.

Are they variables inherent to regex?

Dave

--
Posted via http://www.ruby-forum.com/\.

7

Abinoam Jr. wrote in post #1135563:

Dear Dave,

From:

Pattern matching sets some global variables :
$~ is equivalent to ::last_match;
$& contains the complete matched text;
$` contains string before match;
$' contains string after match;
$1, $2 and so on contain text matching first, second, etc capture group;
$+ contains last capture group.

Abinoam Jr.

Thank you - thats a huge help!

Dave

···

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Posted via http://www.ruby-forum.com/\.

8

There is one important thing you should know: these global variables
are not really global. They are per thread and per scope.

$ ruby -e '/fo+/ =~ "foo"; p $~;Thread.new {p $~}.join'
#<MatchData "foo">
nil
$ ruby -e 'def m(s) /f.+/ =~ s; p $~ end;/f.+/ =~ "foo"; p $~;m("faa");p $~'
#<MatchData "foo">
#<MatchData "faa">
#<MatchData "foo">
$ ruby -e '/f.+/=~"foo";p $~;1.times {/f.+/=~"faa";p $~};p $~'
#<MatchData "foo">
#<MatchData "faa">
#<MatchData "faa">

This is convenient as it avoids multiple matches to interfere with each other.

Btw. you can also make the regex fill local variables:

$ ruby -e '/(?<match>f.+)/=~"foo";p match'
"foo"
$ ruby -e '/f(?<match>.+)/=~"foo";p match'
"oo"

Kind regards

robert

···

On Wed, Feb 5, 2014 at 3:56 AM, Dave Castellano <lists@ruby-forum.com> wrote:

Abinoam Jr. wrote in post #1135563:

Class: Regexp (Ruby 2.1.0)

Pattern matching sets some global variables :
$~ is equivalent to ::last_match;
$& contains the complete matched text;
$` contains string before match;
$' contains string after match;
$1, $2 and so on contain text matching first, second, etc capture group;

Thank you - thats a huge help!

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/