Robert Feldt <feldt / ce.chalmers.se> wrote:
>
>Hi,
>
>A q for you recursively minded folks out there:
>Anyone got a Ruby regexp matching valid Ruby regexps?
>
Unless Ruby's Regexp engine has some extensions I have
not heard about, this is impossible.

A Ruby regexp can contain any set of balanced parens.
Balanced parens are a classic problem that is unsolvable
in a regular expression.

Keep in mind that regular expressions are methods of
stating a pattern to look for.  They are not a general
parsing tool.  Attempting to use them as the latter is
like using a hammer as a screw-driver.  It kinda works
until you have a delicate problem...

Instead use regular expressions to find tokens and then
proceed with standard parsing techniques.

Cheers,
Ben
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