Regexp rescue method

[th8254]

How would I write a rescue method to recover from a failed regexp
parsing?

-Thanks

 

[Tim Hunter]

How would I write a rescue method to recover from a failed regexp
parsing?

-Thanks

I don't think that raises an error. You'd have to check for a nil result
instead.

 

[James Edward Gray II]

I don't think that raises an error. You'd have to check for a nil
result instead.

I took the question to mean, how would I recover from a malformed
Regexp error like:

re = /[/

SyntaxError: compile error
(irb):1: invalid regular expression; '[' can't be the last character
ie. can't start range at the end of pattern: /[/
from (irb):1

I don't know of a way to recover from that specific example either,
which is why I didn't jump to answer:

begin ?> re = /[/
rescue SyntaxError
puts "Your Regexp is malformed."
end

SyntaxError: compile error
(irb):3: invalid regular expression; '[' can't be the last character
ie. can't start range at the end of pattern: /[/
from (irb):6

But, if you change the way the expression is built, it does seem to
become a recoverable error:

begin ?> re = Regexp.new("[")
rescue RegexpError
puts "Your Regexp is malformed."
end

Your Regexp is malformed.
=> nil

James Edward Gray II

 

[Florian Aßmann]

I can't catch it even with rescue Object... wow.

you could also eval it, k, thats even more evil:

begin
re =3D eval '/abc/'
p re
re =3D eval '/[/'
rescue SyntaxError
puts 'hit'
end

Sincerely
Florian

I don't think that raises an error. You'd have to check for a nil
result instead.

=20
I took the question to mean, how would I recover from a malformed Regex= p
error like:
=20

re =3D /[/

SyntaxError: compile error
(irb):1: invalid regular expression; '[' can't be the last character ie= =2E
can't start range at the end of pattern: /[/
from (irb):1
=20
I don't know of a way to recover from that specific example either,
which is why I didn't jump to answer:
=20

begin ?> re =3D /[/
rescue SyntaxError
puts "Your Regexp is malformed."
end

SyntaxError: compile error
(irb):3: invalid regular expression; '[' can't be the last character ie= =2E
can't start range at the end of pattern: /[/
from (irb):6
=20
But, if you change the way the expression is built, it does seem to
become a recoverable error:
=20

begin ?> re =3D Regexp.new("[")
rescue RegexpError
puts "Your Regexp is malformed."
end

Your Regexp is malformed.
=3D> nil
=20
James Edward Gray II
=20
=20
=20[/QUOTE]