Object: rules_table

Description

Rules_table objects are just another way of specifying rules, except the conditions are in a table instead of using the if-then format. For example the following rules:

if shape = "circle" then area = pi * radius ** 2, 
if shape = "square" then area = side * side

can be specified in a rules_table named 'area':

id

area

path

/

type

single_value

rules

shape

area

"circle"

pi * radius ** 2

"square"

side * side

Not all rules can be specified in tables, only those whose conditions are 'anded' together. For example, this rules_table (named 'walk'):

pet	weight	health	walk
"cocker spaniel"	< 30	good	1

is equivalent to:

if pet = "cocker spaniel" and weight < 30 and health = good 
then walk = 1 

You can also specify multiple conditions in a column using 'and', 'or' and 'not'. For example:

colors	area	thing
include "blue" and include "red"	>= 100 or < 10	"a purplish sort of thing"
include "blue" and (not include "red") or include "red" and (not include "blue")	*	"not purple thing"

The special condition '*' will match any value.

The KnowledgeWright reasoning engine examines the rows in the rules_table in order starting with the first row and continuing onto the last.

Rules_Table Properties

Rules_tables can use all the comparators, functions, arithmetic operators and date arithmetic available for rules, and must following the same syntatic restrictions. The properties of rules_tables are: