Introduced new prefix query features.

[yaz-moved-to-github.git] / README

diff --git a/README b/README
index 3149ec5..5079588 100644 (file)
--- a/README
+++ b/README
@@ -33,6 +33,27 @@ client osi:0103/find2.denet.dk:4500
 
 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>.
+
+Eg.:
+
+Andersen
+
+"Hans Andersen"
+
+@and @attr 1=1 andersen @attr 1=4 @attr 4=2 duckling
+
+@attrset Bib-1 @and @attr GILS 2=2008 Washington @attr 1=21 weather
+
 The directories:
 
 doc     - Documentation.
@@ -51,7 +72,7 @@ asn     - This module implements the Z39.50/SR protocol. The best way
        which defines structure and type definitions for each of the
        types introduced in the protocol specification.
 
-yazlib  - This module implements the transport transparency
+comstack- This module implements the transport transparency
        stack (COMSTACK). The comstack implements a generic interface
        for exchanging BER-encoded records over a network. It supports
        the 'American' mode of exchanging the records straight over