Module datarush.library
Package com.pervasive.datarush.functions

Class WidestInputTyper

  • All Implemented Interfaces:
    FunctionTyper
    public class WidestInputTyper
extends Object
implements FunctionTyper
    A typer determining the output type of a function based on the types of one or more inputs. If more than one input is used, the widest of the inputs is used.

    • Constructor Detail

      • WidestInputTyper

        public WidestInputTyper​(int... indices)
        Defines a type using the specified inputs to determine the output type.
        Parameters:
        indices - the input arguments to use to determine type. If none are supplied, all arguments are used.

      • WidestInputTyper

        public WidestInputTyper​(ScalarTokenType bound,
                        int... indices)
        Defines a type using the specified inputs to determine the output type. The given type is the upper bound on the output type. While this also implies an upper bound on the selected inputs, an explicit bound should also be declared in the ScalarFunctionDescriptor.
        Parameters:
        bound - the upper bound for the function
        indices - the input arguments to use to determine type. If none are supplied, all arguments are used.

    • Method Detail

      • computeUpperBound

        public ScalarTokenType computeUpperBound​(FunctionContext ctx)
        Description copied from interface: FunctionTyper
        Calculates the upper bound for the function given the provided context.

        The context contains the upper bounds on the types of all arguments to the function. If a argument is not a subclass of ScalarValuedFunction, its type is null.

        Specified by:
        computeUpperBound in interface FunctionTyper
        Parameters:
        ctx - the context of the function being processed
        Returns:
        the upper bound on the function

      • computeResultType

        public ScalarTokenType computeResultType​(FunctionContext ctx)
        Description copied from interface: FunctionTyper
        Calculates the result type for the function given the provided context.

        The context contains the actual result types of all arguments to the function. If a argument is not a subclass of ScalarValuedFunction, its type is null.

        Specified by:
        computeResultType in interface FunctionTyper
        Parameters:
        ctx - the context of the function being processed
        Returns:
        the result type of the function