Class Oi

Introduction

This class provides a mechanism for mapping objects to integers, and vice versa. Its name, "Oi," is short for "Object integer."

Synergy/DE, being a type-safe language, is not friendly to the idea of passing an object as a parameter where a primitive type is expected. Nor can you pass a record or group that contains an object. Thus, a disconnect can easily occur when you wish to use an object in a routine that must be called back from a mechanism where only primitives can be passed.

The obvious solution to this problem is to keep an array of the objects you need to reference, and pass their indices instead of their references. Care must be taken to keep the indices from changing as objects are added or removed. That's what this class encapsulates.

Naturally, adding an object to this mechanism creates a reference, so you must be careful to "drop" an object from Oi when you no longer need it. Oi will reuse that index of its internal array.

Contents

1. Introduction
2. Contents
3. Explanation of symbols used
4. Member reference
   1. drop - Remove an object from Oi
   2. i2o - Return the object for an integer
   3. o2i - Return the integer for an object

Explanation of symbols used

Words in italics indicate an instance of a class. The word corresponds to the class name, except where more than one instance is represented in the same statement. In that case a number (2, 3, etc.) is appended to the class name.

Words in normal typeface are to be taken literally (required punctuation, class name in a static reference, method name, etc.)

The symbol => is used to separate an expression (on the left) from its return value (on the right).

An ellipsis (...) indicates that the previous argument may be repeated any number of times. The description will indicate whether one instance is required.

Member reference