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From Jack Krupansky <jack.krupan...@gmail.com>
Subject Re: Spaces in regular expressions
Date Mon, 15 Feb 2016 15:22:12 GMT
You can have two parallel fields, one tokenized as a programming language
would (identifiers, operators) and one using the keyword tokenizer for each
line. You have to decide whether to treat each line as a separate Lucene
document or treat each source file as a multivalued field, one value per
source line. And then there is the issue of code sequences that span source
lines.

-- Jack Krupansky

On Mon, Feb 15, 2016 at 8:30 AM, Kudrettin Güleryüz <kudrettin@gmail.com>
wrote:

> Since documents are source code, I am considering matching on operators
> too.
>
> Using whitespace analyzer, A=foo(){ would be a single term, A = foo () {
> would be  five terms. Different documents can have a different combination
> of the identifiers and operators in the example. A regexp query like
> /A\s*=\s*foo\s*()\s*{/ could match all of them if multi term regexp was
> allowed. Is it not allowed by default, or not possible at all? Any
> suggestions?
>
> On Sat, Feb 13, 2016 at 5:09 PM Jack Krupansky <jack.krupansky@gmail.com>
> wrote:
>
> > Just to be clear, the whitespace tokenizer would treat "A=foo(){" as a
> > single token. I presume you want "A" and "foo" to be separate terms.
> >
> > You still haven't indicated what regex you were considering. Try
> explaining
> > your query in plain English. I mean, do you want to search for two
> keywords
> > with any operator sequence between them? Or... do you want to match on
> > operators as well but simply want to ignore whitespace?
> >
> > Generally, the standard analyzer/tokenizer is better/easier - you can
> > simply query "A foo" and it will match all three of you statements.
> >
> > -- Jack Krupansky
> >
> > On Sat, Feb 13, 2016 at 4:29 PM, Kudrettin Güleryüz <kudrettin@gmail.com
> >
> > wrote:
> >
> > >  As mentioned, document is a source code. As you know all below
> statments
> > > are equal:
> > > A = foo() {
> > > A=foo(){
> > > A= foo(){
> > > ...
> > >
> > > With standard whitespace analyzer in action statements wanted to match
> > can
> > > be on one to five terms in this case. If spacing is definite, I could
> go
> > > either a phrase search or regexep. Any suggestions for this case?
> > >
> > >
> > >
> > > On Sat, Feb 13, 2016 at 1:34 PM Jack Krupansky <
> jack.krupansky@gmail.com
> > >
> > > wrote:
> > >
> > > > Obviously you wouldn't need to do a regex for simply terms like foo
> and
> > > bar
> > > > - just use simple terms and quoted phrase to match "foo bar". If you
> > > really
> > > > do need to do complex pattern regexes and match across adjacent
> terms,
> > > your
> > > > best bet is to keep a copy of the source text in a separate string
> (not
> > > > tokenized text) field and then you can do a complex regex that spans
> > > terms
> > > > (and only do that if normal span queries don't do what you need.)
> > > >
> > > > What does your typical cross-term regex actually look like?
> > > >
> > > >
> > > > -- Jack Krupansky
> > > >
> > > > On Sat, Feb 13, 2016 at 1:25 PM, Uwe Schindler <uwe@thetaphi.de>
> > wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > That's very easy to explain: Regexp queries only work on terms, you
> > > > > already said it in your introduction. There is no phrase query in
> > > Lucene
> > > > > that accepts regular expressions.
> > > > >
> > > > > Uwe
> > > > >
> > > > > -----
> > > > > Uwe Schindler
> > > > > H.-H.-Meier-Allee 63, D-28213 Bremen
> > > > > http://www.thetaphi.de
> > > > > eMail: uwe@thetaphi.de
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Kudrettin Güleryüz [mailto:kudrettin@gmail.com]
> > > > > > Sent: Saturday, February 13, 2016 7:14 PM
> > > > > > To: java-user@lucene.apache.org
> > > > > > Subject: Spaces in regular expressions
> > > > > >
> > > > > > Hello,
> > > > > >
> > > > > > I am using standard whitespace analyzer to index a source code
> > > document
> > > > > > using Lucene 5.
> > > > > >
> > > > > > I understand that a document with content foo bar would have
only
> > two
> > > > > > terms: foo and bar.  When I search for "foo bar" it normally
> > matches
> > > > the
> > > > > > document. Similarly a regexp query /foo/ or /bar/ also matches
> the
> > > > > > document.
> > > > > >
> > > > > > Can you help me understand why doesn't a regexp query like /foo
> > bar/
> > > > > > doesn't match the document?
> > > > > >
> > > > > > Thank you,
> > > > > > Kudret
> > > > >
> > > > >
> > > > >
> ---------------------------------------------------------------------
> > > > > To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> > > > > For additional commands, e-mail: java-user-help@lucene.apache.org
> > > > >
> > > > >
> > > >
> > >
> >
>

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