Documentation on the Utils APL workspace
by Blake McBride
I programmed business applications (as opposed to scientific or mathematical applications) in APL from 1980 to 1985. During that time, I developed a variety of utilities to make the construction of business applications easy. This repository represents my port of those utilities to GNU APL.
The workspace contains three classes of functions as follows:
In general, all of the utility functions start in an uppercase letter. It is assumed that application functions would all start with a lowercase letter in order to avoid conflicts.
Typically an application would start with a function named ‘start’, and ⎕LX←’Auto’. When an application is loaded, Auto gets run in order to initialize certain things, and then the application specific entry point ‘start’ is called. Following this procedure is necessary in order for the Application runtime utilities to function. This is because they assume certain initialization had taken place before they are called.
Calling Auto without a start function causes the application to stop with a SI. At this point the Application runtime functions may be used since Auto already initialized everything. The Generic utilities and Development utilities do not have this requirement and may be used at any point.
Most of the Application runtime utilities are used for I/O such as input and output interaction with the user. The Generic utilities are used to handle generic functionality such as formatting a date, date conversion, stripping or parsing a string, etc. These all work stand-alone (without any pre-existing context). Lastly, the Development utilities are used by a developer to do things like print a function or workspace, search or search and replace code in a workspeace, etc.
Although I have no intention of exhaustively documenting everything, I do hope to document enough to provide a good start at using these utilities. As a subject of another document, I hope to provide a rationale for the use of APL in business applications - even today!
The following documents are provided:
DevUtils.txt Development utilities documentation
AppUtils.txt Application runtime utilities
Source code at: https://github.com/blakemcbride/APLUtils