Skip to main content

Calling Functions

These functions allow you to invoke user-defined functions.

APPLY()​

APPLY(functionName, arguments) → retVal

Dynamically call the function funcName with the arguments specified. Arguments are given as array and are passed as separate parameters to the called function.

Both built-in and user-defined functions can be called.

  • funcName (string): a function name
  • arguments (array, optional): an array with elements of arbitrary type
  • returns retVal (any): the return value of the called function
APPLY( "SUBSTRING", [ "this is a test", 0, 7 ] )
// "this is"

ASSERT() / WARN()​

ASSERT(expr, message) → retVal
WARN(expr, message) → retVal

The two functions evaluate an expression. In case the expression evaluates to true both functions will return true. If the expression evaluates to false ASSERT will throw an error and WARN will issue a warning and return false. This behavior allows the use of ASSERT and WARN in FILTER conditions.

  • expr (expression): AQL expression to be evaluated
  • message (string): message that will be used in exception or warning if expression evaluates to false
  • returns retVal (bool): returns true if expression evaluates to true
FOR i IN 1..3 FILTER ASSERT(i > 0, "i is not greater 0") RETURN i
FOR i IN 1..3 FILTER WARN(i < 2, "i is not smaller 2") RETURN i

CALL()​

CALL(funcName, arg1, arg2, ... argN) → retVal

Dynamically call the function funcName with the arguments specified. Arguments are given as multiple parameters and passed as separate parameters to the called function.

Both built-in and user-defined functions can be called.

  • funcName (string): a function name
  • args (any, repeatable): an arbitrary number of elements as multiple arguments, can be omitted
  • returns retVal (any): the return value of the called function
CALL( "SUBSTRING", "this is a test", 0, 4 )
// "this"