- Function
A function is a technique of wrapping code to perform a certain task and then return a value.
- Expression
An expression is a list of one or more functions which are applied one after the other.
- Argument
- Parameter
A parameter is directly defined in the function and alter its code influencing the value returned by this function. Predicates also accept parameters.
- Optional parameter
Some parameters are optional and can be not specified when invoking the function or predicate. They usually take a default value.
- Predicate
A predicate is a function that returns a boolean value.
- Predication
A predication is a list of one or more predicates which are combined to eventually return a single boolean.
- Combinational operator
A combinational operator defines how two predicates must be combined to return a single boolean. The operators are classical operators of the logical algebra
and,or,xor.
- Type
Each value is of a specific type. Types can be
text,numeric,dateTime,boolean.- Scalar value
A scalar value can be a variable, a parameter, an argument, or the value returned by a function. The data type of a scalar value contains only a single value.
- Context
A context is set of values which can be used in an expression or predication. During the evaluation of the expression or predication, the values in the context are not modified. The context can be modified between two evaluations of the expression without having to redefine this expression.
- Variable
A variable is a container for storing a data value. The variables are stored in the context and each of them has a unique name used to address them.
- Current object
A specific variable in the context that can be addressed by the means of named properties or an index.
