Class UdfResolver

  • All Implemented Interfaces:
    Resolver

    public class UdfResolver
    extends Object
    implements Resolver
    Resolver for user-defined functions.
    Since:
    2.0
    Author:
    jhyde
    • Method Detail

      • getName

        public String getName()
        Description copied from interface: Resolver
        Returns the name of the function or operator.
        Specified by:
        getName in interface Resolver
      • getDescription

        public String getDescription()
        Description copied from interface: Resolver
        Returns the description of the function or operator.
        Specified by:
        getDescription in interface Resolver
      • getSignature

        public String getSignature()
        Description copied from interface: Resolver
        Returns a string describing the syntax of this function, for example
        StrToSet()
        Specified by:
        getSignature in interface Resolver
      • getSyntax

        public Syntax getSyntax()
        Description copied from interface: Resolver
        Returns the syntax with which the function or operator was invoked.
        Specified by:
        getSyntax in interface Resolver
      • getFunDef

        public FunDef getFunDef()
        Description copied from interface: Resolver
        Returns a representative example of the function which this Resolver can produce, for purposes of describing the function set. May return null if there is no representative function, or if the Resolver has a way to describe itself in more detail.
        Specified by:
        getFunDef in interface Resolver
      • resolve

        public FunDef resolve​(Exp[] args,
                              Validator validator,
                              List<Resolver.Conversion> conversions)
        Description copied from interface: Resolver
        Given a particular set of arguments the function is applied to, returns the correct overloaded form of the function.

        The method adds an item to conversions every time it performs an implicit type-conversion. If there are several candidate functions with the same signature, the validator will choose the one which used the fewest implicit conversions.

        Specified by:
        resolve in interface Resolver
        Parameters:
        args - Expressions which this function call is applied to.
        validator - Validator
        conversions - List of implicit conversions performed (out)
        Returns:
        The function definition which matches these arguments, or null if no function definition that this resolver knows about matches.
      • requiresExpression

        public boolean requiresExpression​(int k)
        Description copied from interface: Resolver
        Returns whether a particular argument must be a scalar expression. Returns false if any of the variants of this resolver allows a set as its kth argument; true otherwise.
        Specified by:
        requiresExpression in interface Resolver
      • getReservedWords

        public String[] getReservedWords()
        Description copied from interface: Resolver
        Returns an array of symbolic constants which can appear as arguments to this function.

        For example, the DrilldownMember may take the symbol RECURSIVE as an argument. Most functions do not define any symbolic constants.

        Specified by:
        getReservedWords in interface Resolver
        Returns:
        An array of the names of the symbolic constants