MYDan::Node - Cluster information interpreter. Extends MYDan::Node::Range
use MYDan::Node; my $a = MYDan::Node->new( cache => '/database/file' ); $a->load( 'foo{2~9}{??==*=={foo,bar}!!baz}.bar' ); ## ... see base class for other methods ...
A cluster query is expressed as a tuple of elements, corresponding to columns of the cache table. See MYDan::Node::DBI::Cache.
Such a query is made when an element is indicated by the select symbol, and the other three are given as query conditions, expressed by a condition symbol followed a range expression. e.g. "{??==*=={foo,bar}!!baz}" may be translated into the following SQL statement,
"SELECT col1 FROM $TABLE WHERE col3 IN ('foo','bar') AND col4!='baz'"
A callback query is expressed as a callback symbol followed by the callback name, and optionally, followed by a query condition. See MYDan::Node::Call.
e.g. "{%%foo!!bar,baz}" means to get all elements returned by callback foo, except those indexed by bar and baz.
Naturally, '*' in a query condition means 'any', i.e. no condition. And a query expression may be recursive.
( in addition to those in the base class )
'??' : select '==' : in '!!' : not
Returns cache db object.
Returns callback object.
( BNF rules additional to those in the base class )
'{' [ <expr> | <call> | <cluster> ] '}'
<call_sym> <string> <query_cond>
[ <select_symbol> <query_cond> ** 3 ] | [ <query_cond> <select_symbol> <query_cond> ** 2 ] | [ <query_cond> ** 2 <select_symbol> <query_cond> ] | [ <query_cond> ** 3 <select_symbol> ]
<condition_symbol> <expr> | <condition_symbol> <regex>
To install MYDan, copy and paste the appropriate command in to your terminal.
cpanm
cpanm MYDan
CPAN shell
perl -MCPAN -e shell install MYDan
For more information on module installation, please visit the detailed CPAN module installation guide.