Data Transformation Engine Functions and Expressions Reference Guide

Chapter 1 - Expressions and Evaluations Using Functions in Expressions
Functions and Expressions Reference Guide
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argument it is used for. The analysis also checks the type of the output argument
when that function is used to directly produce an output data object.
The output argument of a function specifies the result that the function produces
for one evaluation. For example, one evaluation of the
ABS function produces one
positive number. One function evaluation may produce multiple outputs. If it does,
the expression that contains that function may produce multiple evaluation sets.
Input Arguments
The input arguments for a function specify the information the function uses to
return a result. Some functions require an exact number of input arguments. For
other functions, the number of input arguments can vary. Optional arguments for
a function are shown in brackets, [ ].
To correctly use a function, you must use the correct arguments in the correct
order.
Each argument can, itself, be an expression. In general, an input argument may
be any of the following:
♦ an object name
♦ a literal
♦ a function-name and its arguments
♦ an operator and its arguments
♦ an enumerated series of literals, such as {a, b, c}
♦ a map name and its arguments
For example, some valid expressions that use the
ABS function are:
ABS ( Quantity:LineItem )
ABS ( UNIQUE ( Quantity:LineItem )
ABS ( Quantity:LineItem - 300 )
Each function has its own expression syntax for its input arguments. For example,
the
ABS function cannot use a map as an argument. See Function Argument
Syntax in Chapter 2 for notation used to specify valid expression syntax.