Operators

Just as a sentence means nothing without a verb, anything you write in RuLa means nothing without operators. They make it possible for a variable to be defined, for a condition to work and for a rule to make sense.

The table below lists all available operators in alphabetical order, with a brief description. For a more extensive description of each individual operator, plus examples, click on it or visit the sub-pages in the menu on the left.

Available Operators and Keywords

Operator	Category	Description
=	Boolean	Compares. Evaluates to either true or false, delivering different outcomes.
!=	Boolean	Compares, true for 'is not equal to'.
>	Boolean	Compares, true for 'greater than'.
>=	Boolean	Compares, true for 'equal to or greater than'.
<	Boolean	Compares, true for 'less than'.
<=	Boolean	Compares, true for 'equal to or less than'.
:=	Special	Assignment, which can have any kind of expression on the right side of the operator.
+, -, /, *, %	Mathematical	Perform basic mathematical calculations.
[ , ]	List	Creates a new list from single values, allowing other list operators to perform actions on the new list.
ADD_YEARS	Date	Takes a date and adds a specified number of years to it.
AFTER	Date	Takes two dates, and checks if the first one comes after the second one.
AFTER_EQUAL	Date	Takes two dates, and checks if the first one comes after, or is the same as, the second one.
ALL	List	Evaluates if all values in a list are true.
and	Boolean	Sets as condition that both expressions have to be true to have the entire expression evaluate to 'true'.
and then	Boolean	Similar as above, but when using 'and then', the second question is only asked when the first evaluates to 'true'.
AVG	Mathematical	Calculates the average value.
AVG_OF_ANY	Known	Calculates the average of available values.
BEFORE	Date	Takes two dates, and checks if the first one comes before the second one.
BEFORE_EQUAL	Date	Takes two dates, and checks if the first one comes before, or is the same as, the second one.
calculated_name	String	Accesses the calculated name of an instance.
CEIL	Mathematical	Returns the value of the given parameter, rounded up to a whole number.
CONCAT	String	Combines two values into one new value, specifying what should separate the two.
contains	List	Goes over a list, which is given on the left of the operator. Evaluates to 'true' if the single value on the right is present in the given list.
contains all	List	Expressions with this operator will only evaluate to 'true' if all values from the list on the right side are present in the list on the left side.
contains any	List	Going over a list, given on the left side of the operator, this operator has the expression evaluate to true if any value from that list is present in a list or the single value given on the right side.
COUNT	List	Returns the number of occurrences of the given parameter.
ensure	Special	Makes sure a case contains at least, for example, 1 Person. (replaces create)
FIRST_ELEMENT	List	Returns the first element from a list.
FLOOR	Mathematical	Returns the value of the given parameter, rounded down to a whole number.
get_attr	Special	Gives access to named properties of an instance using expressions.
get_properties	Special	Returns specific information on an instance's properties.
in	List	Checks if a value is present in a taxonomy.
instances	Special	Returns all instances of the given type(s) living on the platform.
is	Special	Basic assignment of a variable.
JOIN	String	Combines a list of values into one new value by appending them.
known	Known	Sets a condition for when a property is not unknown.
LIST_OF_ANY	Known	Builds a list of only the values that are available out of all the values it is given.
MAP	List	Performs the same action on each individual value in a list.
MAX	Mathematical	Returns the highest value.
MAX_OF_ANY	Known	Returns the highest out of available values.
MIN	Mathematical	Returns the lowest value.
MIN_OF_ANY	Known	Returns the lowest out of available values.
not	Boolean	A negation.
not in	List	Evaluates to true if the given value is absent from the specified taxonomy.
NOW	Date	Current date and time.
ontology	Special	Sets a condition based on the type of ontology.
optional	Special	The rule can accept, but will not require, for example, a third person.
or	Boolean	When just one of the two given expressions is true, the entire expression evaluates to 'true'.
or else	Boolean	Similar to above, but the second question is only asked if the first has been answered.
roles	Special	Sets a condition based on role(s).
ROUND	Mathematical	Returns the value of the given parameter, rounded to a whole number.
self	Special	Refers to the current instance where you use it.
SNEAKY	Known	Wrapping an expression with SNEAKYhas the system ignore the expression, if the information used in it is not available.
SOME	List	Evaluates if any value in a list is true.
SUBTRACT_YEARS	Date	Takes a date and subtracts a specified number of years to it.
SUM	Mathematical	Adds up numbers.
SUM_OF_ANY	Known	Adds available numbers.
SUM_PRODUCT	Mathematical	Multiplies values in one list with values on the same index in another list. Returns the sum of the multiplications.
UNION	List	Combines the elements of two sets into one single set.
UNION_OF_ANY	Known	Creates a combined list of the available values and lists out of all values and lists you provide.
unknown	Known	Sets a condition for when a property is unknown.
YEARS_AGO	Date	Calculates the number of years since a given date.