[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[ANN] hyper search engine 0.2

From: Amirouche Boubekki
Subject: [ANN] hyper search engine 0.2
Date: Sun, 19 Jun 2016 11:49:02 +0200
User-agent: Roundcube Webmail/1.1.2


Yesterday someone on IRC asked for a new feature; the ability
to use xor/and/not/or to express queries. So here is it!

# Kesako?

The implementation is straight forward. Actually I defined
`xor*`, `and*`, `not*` and `or*` procedures that looks like

(define* ((xor* a b) uid)
  (if (procedure? a)
      (if (procedure? b)
          ((xor* (a uid) (b uid)) uid)
          ((xor* (a uid) b) uid))
      (if (procedure? b)
          ((xor* a (b uid)) uid)
          (xor a b))))

As you can see it only accepts two arguments :(

Luckily you do no need to understand that to use it,
but it looks funny. That's why I pasted it.

Anyway, given a list of uids that you can retrieve with
`(documents db)` or `(search* db tokens ...)` you can filter
the results with the help of `(keyword db name)`:

(filter (and* (keyword db "hypermove") (keyword db "guile")) uids)

This is equivalent to `(search* db "hypermove" "guile")` but it is less

Previously you could not for instance query the following:

(and* (keyword db "commercial") (or* (keyword db "hypermove") (keyword db "gnu")))

Right now, `keyword` is an implementation detail. But in
the future maybe, you could think of other ways to filter
documents for instance based on some kind of ranking.

# Note on performance

Now a word on `(documents db)`. `documents` does almost
a full scan of a database... To speed things up a little,
you rely on `search*` which is faster but you have
to reword your query. For instance, the previous query,
could actually be done like that:

(filter (or* (keyword db "hypermove") (keyword db "gnu")) (search* db "commercial"))

The documentation is up-to-date on the website:


Amirouche ~ amz3 ~

reply via email to

[Prev in Thread] Current Thread [Next in Thread]