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

Class FixedType

java.lang.Object
com.pervasive.datarush.functions.FixedType
All Implemented Interfaces:
FunctionTyper
public class FixedType extends Object implements FunctionTyper
A typer for functions which return a fixed, known type.

  • Constructor Details

    • FixedType

      public FixedType(ScalarTokenType type)
      Creates a typer which always returns the given type.
      Parameters:
      type - the return type of the function. This must not be an abstract type.
      Throws:
      IllegalArgumentException - if the type is not a valid return type for functions

  • Method Details

    • 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