Added doc about proximity in PQF.

diff --git a/CHANGELOG b/CHANGELOG
index 77f398d..e34f2d9 100644 (file)
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 Possible compatibility problems with earlier versions marked with '*'.
 
+Proximity operator added to Prefix Query Format (PQF).
+
 In test client command "base" accepts multiple databases.
 
 Fixed bug in cs_close stack that caused trouble with WINSOCK.

diff --git a/README b/README
index 8096b34..d144894 100644 (file)
--- a/README
+++ b/README
@@ -35,14 +35,21 @@ Use '?' to get a list of the available commands.
 
 The current query language is a bit awkward, but functional:
 
-query    ::= ['@attrset' <attribute-set>] rpn
-rpn      ::= complex | simple | attr rpn
-complex  ::= operator rpn rpn
-operator ::= '@and' | '@or' | '@not'.
-simple   ::= term | set.
-term     ::= <word> | '"' <term> ... '"'.
-set      ::= '@set' <setname>.
-attr     ::= '@attr' [<attribute-set>] <number> '=' <number>.
+query     ::= ['@attrset' <attribute-set>] rpn
+rpn       ::= complex | simple | attr rpn
+complex   ::= operator rpn rpn
+operator  ::= '@and' | '@or' | '@not' | '@prox' proximity
+simple    ::= term | set.
+term      ::= <word> | '"' <term> ... '"'.
+set       ::= '@set' <setname>.
+attr      ::= '@attr' [<attribute-set>] <number> '=' <number>.
+proximity ::= exclusion distance ordered relation which unit
+exclusion ::= '1' | '0' | 'void'
+distance  ::= <number>
+ordered   ::= '1' | '0'
+relation  ::= <number>
+which     ::= 'known' | 'private'
+unit      ::= <number>
 
 Eg.: