## ŒDESC Describe public members

Implemented for Internal, External and System classes.

Syntax:

namelist „ objref.ŒDESC N
namelist „ classref.ŒDESC N
namelist „ ŒDESC N (Within user-defined method, same as ŒTHIS.ŒDESC N)

ŒDESC is similar to ŒNL in that it returns a list of the public members of a class as a character matrix. However, it also provides additional information about the parameters of each method, including type information if appropriate. It is especially useful for strongly-typed architectures such as Java and .Net. It can be used as a method either of a class, or of an instance of a class.

The right argument is a scalar or vector which indicates which types of class member should be included in the result, using the same codes as ŒNL:

> Code | Type of member
> 2 | Properties
> 3 | Function methods
> 4 | Operator methods
> 8 | Events
> 10 | Constructors

For Internal classes, ŒDESC returns just the names for properties, and the function header (excluding the localised names) for function and operator methods:

    Point {
      X
      Y

      ’R„MAG
        R„((X*2)+(Y*2))*0.5
      ’
    }
          Point.ŒDESC 2      © Applied to a class
    X
    Y
          PT„ŒNEW 'Point'
          PT.ŒDESC 2 3       © Applied to an object (properties and methods)
    R„MAG
    X
    Y

For External classes in Java or .Net, ŒDESC shows the types of properties, method parameters, and results. Because a given method name may be overloaded (i.e. exist in different forms, according to the number and types of parameters provided to it), a given method name may appear more than once:

          NetPT„'.net' ŒNEW 'System.Drawing.Point'

          NetPT.ŒDESC 2      © Properties
    System.Drawing.Point Empty
    Boolean IsEmpty
    Int32 X
    Int32 Y

          NetPT.ŒDESC 10     © Constructors (overloaded)
    Void Point(Int32, Int32)
    Void Point(System.Drawing.Size)
    Void Point(Int32)

          NetPT.ŒDESC 3      © Methods
    System.Drawing.Point Add(System.Drawing.Point, System.Drawing.Size)
    System.Drawing.Point Ceiling(System.Drawing.PointF)
    Boolean Equals(System.Object)
    Boolean get_IsEmpty()
    Int32 get_X()
    Int32 get_Y()
    Int32 GetHashCode()
    System.Type GetType()
    Void Offset(Int32, Int32)
    Void Offset(System.Drawing.Point)
    System.Drawing.Point op_Addition(System.Drawing.Point, System.Drawing.Size)
    Boolean op_Equality(System.Drawing.Point, System.Drawing.Point)
    System.Drawing.Size op_Explicit(System.Drawing.Point)
    System.Drawing.PointF op_Implicit(System.Drawing.Point)
    Boolean op_Inequality(System.Drawing.Point, System.Drawing.Point)
    System.Drawing.Point op_Subtraction(System.Drawing.Point, System.Drawing.Size)
    System.Drawing.Point Round(System.Drawing.PointF)
    Void set_X(Int32)
    Void set_Y(Int32)
    System.Drawing.Point Subtract(System.Drawing.Point, System.Drawing.Size)
    System.String ToString()
    System.Drawing.Point Truncate(System.Drawing.PointF)

For the R interface, ŒDESC can be used to produce a list of all the R functions which are available in the currently-loaded packages, together with the parameters and default values (except for primitive functions). This will usually be a large list (several thousand functions):

          r„'r' Œnew 'r'
          fns„r.Œdesc 3
          ½fns
    2037 117
          fns[1445+¼5;]
    pwilcox (q, m, n, lower.tail = TRUE, log.p = FALSE)
    q (save = "default", status = 0, runLast = TRUE)
    qbeta (p, shape1, shape2, ncp = 0, lower.tail = TRUE, log.p = FALSE)
    qbinom (p, size, prob, lower.tail = TRUE, log.p = FALSE)
    qbirthday (prob = 0.5, classes = 365, coincident = 2)

Topic: APLX Help : Help on APL language : System Methods : ŒDESC Describe members

[ Previous | Next | Contents | Index ]