Re: Char-folding: how can we implement matching multiple characters as a single "thing"?

[Paul Eggert <eggert@cs.ucla.edu>]

On 11/30/2015 07:54 AM, Artur Malabarba wrote:
> Does anyone have alternative ideas?

Sure, scan the pattern greedily for possible sequences, left-to-right.  
In your example "fix" should expand to the regexp "\\([f][i]\\|fi\\)x" 
(where the "fi" is the ligature character), because once the "fi" is 
found, the scanner won't look for "ix" as a single character. This 
should cause the regexp to grow only polynomially rather than 
exponentially. The polynomial version won't match as many strings as the 
exponential version, but in practice it should be good enough.