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A comment on Is there a regular expression to detect a valid regular expression?. Parent comment

Re:Is there a regular expression to detect a valid regular e... by raldi on Sunday September 08, 2019 @10:11AM (#20910639)
Sure there is. Read the linked answer, or just google it.

Example:

https://regular-expressions.mobi/recurse.html?wlr=1

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Re:Is there a regular expression to detect a valid regular e... by jtanderson on Sunday September 08, 2019 @10:21AM (#20910703)
Right but parent is thinking of the quesion "is the language of valid regular expressions itself regular?", which a very different question and of course false by an easy application of the pumping lemma. However, as shown in the SO answer, they "cheat" by using some features that don't align completely with the mathematical definitions.

edit: typo.

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Re:Is there a regular expression to detect a valid regular e... by josalhor on Sunday September 08, 2019 @10:15AM (#20910661)
It depends if we're talking regex in the mathematical sense or in the programming one.
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