Regex.recompile

You're seeing just the function recompile, go back to Regex module for more information.
Link to this function

recompile(regex)

View Source (since 1.4.0)

Specs

recompile(t()) :: {:ok, t()} | {:error, any()}

Recompiles the existing regular expression if necessary.

This checks the version stored in the regular expression and recompiles the regex in case of version mismatch.