[erlang-questions] [eeps] EEP 9

[Fredrik Svahn]

Thanks, good suggestion. I will add it.

BR /Fredrik

On Fri, Mar 7, 2008 at 1:41 PM, Serge Aleynikov <saleyn@REDACTED> wrote:
> In addition to what others already have said, this function would be
>  helpful:
>
>         binary:join(List, Delim) -> binary()
>
>         where:
>            List  = [binary()] | [string()]
>            Delim = binary() | string()
>
>         Examples:
>            > binary:join([<<"abc">>, <<"def">>], <<$|>>).
>            <<"abc|def">>
>
>            > binary:join(["abc", "def"], [$|]).
>            <<"abc|def">>
>
>  Very good work!
>
>  Regards,
>
>  Serge
>
>
>
>  Fredrik Svahn wrote:
>  > Thanks for the positive response both here an on the EEPs mailing list!
>  >
>  > My suggestion is that we continue the discussion regarding EEP-9 here
>  > on the erlang-questions mailing list since it has a broader audience
>  > than eeps@REDACTED I think it would make it a lot easier if we can
>  > keep it in this thread.
>  >
>  > For those who do not subscribe to the eeps mailing list, I would like
>  > to once again stress that this EEP does not cover improvements which
>  > requires changes to the compiler. It has been suggested to me that the
>  > smaller the EEP the faster it gets implemented so let us please keep
>  > the scope as narrow as possible. There is always room for new EEPs.
>  >
>  > A shortcut to EEP-9: http://www.erlang.org/eeps/eep-0009.html
>  >
>  > Now, to answer your questions:
>  >
>  >> 1) Can the reference implementation be made available publicly as a
>  >> patch to R12B-1?  (Or actually in any fashion would be great.)
>  >
>  > The reference implementation in erlang is attached, the c part will
>  > follow in the next message as there is a maximum message size on
>  > erlang-questions. It matches the described functions minus what was
>  > added after a first round of comments from the OTP developers (the
>  > regexps for instance are probably going to have many more features
>  > after what I hear!). I may also have added one or two relatively
>  > simple functions, e.g. atom_to_binary, after the implementation was
>  > submitted.
>  >
>  >> 2) Which algorithm was choosen for the binary:match()?  For multiple
>  >> keyword, Aho-Corasick would be great, especially if the interface was
>  >> something like this:
>  >
>  > In the reference implementation Aho-Corasick was indeed used for
>  > multiple keywords. Boyer-Moore was a logical choice for single
>  > keywords and there was even a brute force approach for short
>  > keywords/searchstrings.
>  >
>  >>    MatchContext = binary:match_compile( [<<"the">>, <<"big">>,
>  >>                                          <<"frog">>] ),
>  >>    Value = <<"when we had a frog, he was big">>,
>  >>    [{3, 14}, {2, 27}] = binary:match( MatchContext, Value )
>  >
>  > Thanks for the comment. I think it makes a lot of sense to have a
>  > separation of the building of the trie and the actual searching as you
>  > suggest, especially if you are searching many binaries for the same
>  > keyword(s). I am not sure how easy it would be to implement it,
>  > though. I guess the returned match context would have to be some kind
>  > of reference or packed in a binary. Maybe someone from the OTP team
>  > could comment on that. I actually wanted to have the same thing for
>  > regular expressions.
>  >
>  > I note that you also want a function which returns all the matches not
>  > just the first one. Given that binary:match/3 takes indexes of the
>  > start and end position of the search it is easy to also add a function
>  > "binary:matches/2" in binary.erl which returns all the matches by
>  > repeatedly calling match/3. Having both "match/2" and "matches/2"
>  > would be similar to how it is done in the regexp module.
>  >
>  > BR /Fredrik
>  >
>  >
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>
>
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