Info Catalog flex: I get an error about undefined yywrap() flex: FAQ flex: How can I expand macros in the input?

flex: How can I change the matching pattern at run time?

 
 How can I change the matching pattern at run time?
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 You can't, it's compiled into a static table when flex builds the
 scanner.
 

Info Catalog flex: I get an error about undefined yywrap() flex: FAQ flex: How can I expand macros in the input?