Formatting a long regex: can a character class [] be split overlines?

[Alexey Muranov]

Hello,
i am wandering if it is possible to split a character class ([...]) in
Ruby regex over multiple lines.

I know that the /x option allows to ignore whitespace, so i can write :

email_format = /\A(
[A-Za-z\d\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]+
\.)*
[A-Za-z\d\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]+
@([a-z\d\-]+\.)+[a-z\d\-]+\z/x

However, if i try to split inside a character class:

name_format = /\A[A-Za-z\d
\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]\z/x

i get the warning:

warning: character class has duplicated range

(apparently it is about the space character being included multiple
times inside []).
I want the space and newlines to be disregarded inside [] to format it
over multiple lines, is this possible?

Thanks,

Alexey.

 

[Jose Calderon-Celis]

[Note: parts of this message were removed to make it a legal post.]

http://es.w3support.net/index.php?db=so&id=150095

 

[7stud --]

Alexey Muranov wrote in post #996071:

Hello,
i am wandering if it is possible to split a character class ([...]) in
Ruby regex over multiple lines.

I know that the /x option allows to ignore whitespace, so i can write :

email_format = /\A(
[A-Za-z\d\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]+
\.)*
[A-Za-z\d\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]+
@([a-z\d\-]+\.)+[a-z\d\-]+\z/x

However, if i try to split inside a character class:

name_format = /\A[A-Za-z\d
\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]\z/x

i get the warning:

warning: character class has duplicated range

(apparently it is about the space character being included multiple
times inside []).
I want the space and newlines to be disregarded inside [] to format it
over multiple lines, is this possible?

Thanks,

Alexey.

1) Never write a regex with thousands of escapes. Are you aware that
inside a character class, the special regex characters lose their
special meaning?

2) Break up long regexes into smaller pieces.


my_char_class = '[A-Za-z#\d!#$%&\'*+-/=?^_`{|}~]'

my_regex = /
\A
#{my_char_class}
[.]
#{my_char_class}
\z
/x


if my_regex.match "?./"
puts 'yes'
end

--output:--
yes

 

[7stud --]

It's also possible to escape a newline:

name_format = /\A[A-Za-z\d\
\!\#\$\%\&\'\*\+\-\/\=\?\^\_\`\{\|\}\~]\z/x

but then you can't indent the second line or else your regex will
contain a bunch of spaces.

 

[7stud --]

You could also use a here doc and avoid having to escape any character
inside the string:

str = <<'LOTS_OF_SYMBOLS'
[A-Za-z\d!#$%&'*+-/=?^_`{|}~]
LOTS_OF_SYMBOLS

puts str.chomp

--output:--
[A-Za-z\d!#$%&'*+-/=?^_`{|}~]