pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / queryparser / README.txt

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+Description of Surround:
+
+Surround consists of operators (uppercase/lowercase):
+
+AND/OR/NOT/nW/nN/() as infix and
+AND/OR/nW/nN        as prefix.
+
+Distance operators W and N have default n=1, max 99.
+Implemented as SpanQuery with slop = (n - 1).
+An example prefix form is:
+
+20n(aa*, bb*, cc*)
+
+The name Surround was chosen because of this prefix form
+and because it uses the newly introduced span queries
+to implement the proximity operators.
+The names of the operators and the prefix and suffix
+forms have been borrowed from various other query
+languages described on the internet.
+
+
+Query terms from the Lucene standard query parser:
+
+field:termtext
+^ boost
+* internal and suffix truncation
+? one character
+
+
+Some examples:
+
+aa
+aa and bb
+aa and bb or cc        same effect as:  (aa and bb) or cc
+aa NOT bb NOT cc       same effect as:  (aa NOT bb) NOT cc
+
+and(aa,bb,cc)          aa and bb and cc
+99w(aa,bb,cc)          ordered span query with slop 98
+99n(aa,bb,cc)          unordered span query with slop 98
+
+20n(aa*,bb*)
+3w(a?a or bb?, cc*)
+
+title: text: aa
+title : text : aa or bb
+title:text: aa not bb
+title:aa not text:bb
+
+cc 3w dd               infix: dual.
+
+cc N dd N ee           same effect as:   (cc N dd) N ee
+
+text: aa 3d bb
+
+For examples on using the Surround language, see the
+test packages.
+
+
+Development status
+
+Not tested: multiple fields, internally mapped to OR queries,
+not compared to Lucene's MultipleFieldQuery.
+
+* suffix truncation is implemented very similar to Lucene's PrefixQuery.
+
+Wildcards (? and internal *) are implemented with regular expressions
+to allow further variations. A reimplementation using
+WildCardTermEnum (correct name?) should be no problem.
+
+Warnings about missing terms are sent to System.out, this might
+be replaced by another stream, and tested for in the tests.
+
+BooleanQueryTst.TestCollector uses a results checking method that should
+be replaced by the checking method from Lucene's TestBasics.java.