[erlang-questions] idea: service pack one

Bjorn Gustavsson <>
Thu Nov 15 13:41:00 CET 2007


Joel Reymont <> writes:

> The difference seems to be in matching an empty binary vs <<_Head:N/
> binary>>.
> 
> Why exactly is the 2nd pattern so much faster?

The first pattern (<<>>) does not match. That was worked around (by the original
author) by adding the following clause:

index(Str, _Char, N) when N > size(Str) ->
    0;

What I did what to make sure that the pattern could match (<<_Head:N/binary>>),
and comment out the now redundant second clause.

/Bjorn
-- 
Björn Gustavsson, Erlang/OTP, Ericsson AB



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