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Unary-tests

A unary-tests expression is a special kind of boolean expression. Unary-tests expressions should be used for the input entries of a decision table (i.e. the conditions of a rule).

A unary-tests expression returns true if one of the following conditions is fulfilled:

  • The expression evaluates to true when the input value is applied to the unary operators.
  • The expression evaluates to true when the input value is assigned to the special variable ?.
  • The expression evaluates to a value, and the input value is equal to that value.
  • The expression evaluates to a list, and the input value is equal to at least one of the values.
  • The expression is equal to - (a dash).

Comparison​

Compares the input value with a given value. Both values must be of the same type.

The input value is passed implicitly as the first argument of the operator.

OperatorDescriptionSupported types
(none)equal toany
<less thannumber, date, time, date-time, duration
<=less than or equal tonumber, date, time, date-time, duration
>greater thannumber, date, time, date-time, duration
>=greater than or equalnumber, date, time, date-time, duration
"valid"

< 10

<= date("2020-04-06")

> time("08:00:00")

>= duration("P5D")

Interval​

Checks if the input value is within a given interval between x and y.

An interval has two boundaries that can be open (x..y) / ]x..y[ or closed [x..y]. If a boundary is closed, it includes the given value (i.e. less/greater than or equal). Otherwise, it excludes the value (i.e. less/greater than).

The input value is passed implicitly to the operator.

(2..5)
// input > 2 and input < 5

]2..5[
// input > 2 and input < 5

[2..5]
// input >= 2 and input <= 5

(2..5]
// input > 2 and input <= 5

Disjunction/or​

Combines multiple unary-test expressions following the ternary logic.

  • Returns true if at least one unary-test evaluates to true.
  • Otherwise, it returns false.
2, 3, 4
// input = 2 or input = 3 or input = 4

< 10, > 50
// input < 10 or input > 50

Negation/not​

Negates a given unary-test expression. The expression can be a comparison, an interval, or a disjunction.

It returns true if the given unary-test evaluates to false.

not("valid")
// input != "valid"

not(2, 3)
// input != 2 and input != 3

Expressions​

When a unary operator is not enough to express the condition, any expression that returns a boolean value can be used, such as invoking a function.

In the expression, the input value can be accessed by the special variable ?.

contains(?, "good")
// checks if the input value (string) contains "good"

ends with(?, "@camunda.com")
// checks if the input value (string) ends with "@camunda.com"