From: gam3-ruby@...3.net
Date: 2016-09-16T13:57:39+00:00
Subject: [ruby-core:77294] [Ruby trunk Feature#12700] regexg heredoc support

Issue #12700 has been updated by Allen Morris.


I don't see how %r helps.

Here is an (rather forced) example of the advantage of a /HEREDOC/

~~~ ruby
a = "one"
b = "two"

raise "error" unless a.match(<</REG/x)[1] == b.match(<</REG/x)[1]
(.) # what we want to match
n   # what we want to skip
e   # more to skip
REG
t   # what we want to skip
w   # more to skip
(.) # what we want to match
REG

raise "error" unless a.match(%r|
(.) # what we want to match
n   # what we want to skip
e   # more to skip
|x)[1] == b.match(%r|
t   # what we want to skip
w   # more to skip
(.) # what we want to match
|x)[1]
~~~


----------------------------------------
Feature #12700: regexg heredoc support
https://bugs.ruby-lang.org/issues/12700#change-60533

* Author: Allen Morris
* Status: Rejected
* Priority: Normal
* Assignee: 
----------------------------------------
There is support for ', ", and ` heredocs, but there is no support for /.

Example code with new feature:

~~~ ruby
first = 'first'

orig = /#{first}
match\s # match
this    # match this
/x

right = <</REGEXP/x
#{first}
match\s # match
this    # match this
REGEXP

raise unless orig == right
~~~

There is no straight forward way to replace a regexp heredoc as a double quote heredoc requires that '\\s' be escaped.
As shown in the code below you can't use the string heredoc to directly replace a regexp heredoc because of this need for extra escaping.

~~~ ruby
first = 'first'

orig = /#{first}
match\s # match
this    # match this
/x

wrong = Regexp.new(<<REGEXP, Regexp::EXTENDED)
#{first}
match\s # match
this    # match this
REGEXP

right = Regexp.new(<<REGEXP, Regexp::EXTENDED)
#{first}
match\\s # match
this    # match this
REGEXP

raise unless orig != wrong
raise unless orig == right
~~~








---Files--------------------------------
regex_heredoc_patch (2.99 KB)


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