Package org.qdl_lang.extensions.examples.basic

Class FEvalFunction

  • All Implemented Interfaces:
    Serializable, QDLFunction
    public class FEvalFunction
extends Object
implements QDLFunction
    Example of a QDL function for a module that accepts a function reference. This takes two arguments 
         f_eval(@f, x)
    and returns 
         f(x)

    Created by Jeff Gaynor
    on 10/7/21 at 4:40 PM

    See Also:
    Serialized Form

    • Field Detail

      • F_NAME

        public static String F_NAME

    • Constructor Detail

      • FEvalFunction

        public FEvalFunction()

    • Method Detail

      • getName

        public String getName()
        Description copied from interface: QDLFunction
        The name of this function as you want it invoked in QDL. This will be what the function is called in the workspace.
        Specified by:
        getName in interface QDLFunction
        Returns:

      • getArgCount

        public int[] getArgCount()
        Description copied from interface: QDLFunction
        The contract is that when QDL invokes this method, it will faithfully give all of the arguments as an array of Objects. Overloading is not possible in QDL (it is weakly typed) except by argument count, so if this is called "foo" and you have versions with 3 and 4 arguments, then f(a,b,c) would be executed with the arguments passed. To achieve overloading for Java methods, have the number of arguments this accepts as the elements of the array. So if this has a value of [1,2,3] then this function will be invoked if called with 1, 2 or 3 arguments and an error by the QDL runtime engine will be raised, if, say, 4 are passed.
        Specified by:
        getArgCount in interface QDLFunction
        Returns:

      • evaluate

        public Object evaluate​(Object[] objects,
                       State state)
        Description copied from interface: QDLFunction
        The method that is invoked by QDL that is the function. It will have the arguments already evaluated and put in to the array of objects. It is up to you to do any checking you see fit. State is supplied if needed.
        Specified by:
        evaluate in interface QDLFunction
        Returns:

      • getDocumentation

        public List<String> getDocumentation​(int argCount)
        Description copied from interface: QDLFunction
        Return documentation to be displayed in the workspace. Short version displays the first line (element of the list) so make sure that is informative. The long version should contain details of use. Best practice is that have a succinct one line description for each arg count and a body that explains the usage more fully.
        Specified by:
        getDocumentation in interface QDLFunction
        Returns: