Package org.esa.snap.core.jexp

Interface Function

public interface Function
A representation of a function. A function has a name, a return type and can be evaluated by passing a number of arguments to it.

Within an expression, a reference to a function is created if the parser encounters a name followed by an argument list and the name can be resolved through the parser's current namespace. The resulting term in this case is an instance of Term.Call.

Version:
$Revision$ $Date$

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    evalB(EvalEnv env, Term[] args)
    Evaluates this function to a boolean value.
    double
    evalD(EvalEnv env, Term[] args)
    Evaluates this function to a double value.
    int
    evalI(EvalEnv env, Term[] args)
    Evaluates this function to an int value.
    int
    getArgType(int argIndex)
    Gets the type of a function's i-th argument.
    String
    getName()
    Gets the function's name.
    int
    getNumArgs()
    Gets the function's number of arguments.
    int
    getRetType()
    Gets the function's return type.
    boolean
    isConst(Term[] args)
     

  • Method Details

    • getName

      String getName()
      Gets the function's name.
      Returns:
      the name, should never be null.

    • getRetType

      int getRetType()
      Gets the function's return type.
      Returns:
      the type, should always be one of the TYPE_X constants defined in the Term class.

    • getNumArgs

      int getNumArgs()
      Gets the function's number of arguments.
      Returns:
      number of arguments.

    • getArgType

      int getArgType(int argIndex)
      Gets the type of a function's i-th argument.
      Parameters:
      argIndex - The argument index.
      Returns:
      an arry of types, each element should always be one of the TYPE_X constants defined in the Term class.

    • evalB

      boolean evalB(EvalEnv env, Term[] args) throws EvalException
      Evaluates this function to a boolean value.
      Parameters:
      env - the application dependant environment.
      args - the (un-evaluated) arguments passed to the function
      Returns:
      a boolean value
      Throws:
      EvalException - if the evaluation fails

    • evalI

      int evalI(EvalEnv env, Term[] args) throws EvalException
      Evaluates this function to an int value.
      Parameters:
      env - the application dependant environment.
      args - the (un-evaluated) arguments passed to the function
      Returns:
      an int value
      Throws:
      EvalException - if the evaluation fails

    • evalD

      double evalD(EvalEnv env, Term[] args) throws EvalException
      Evaluates this function to a double value.
      Parameters:
      env - the application dependant environment.
      args - the (un-evaluated) arguments passed to the function
      Returns:
      a double value
      Throws:
      EvalException - if the evaluation fails

    • isConst

      boolean isConst(Term[] args)
      Returns:
      true, if this symbol has a constant value with respect to the given arguments and to any EvalEnv, including null.