From: Roger Hui <r...@PLANET.EON.NET>
Subject: Re: Learning J from the Dictionary
The choice of the title of the J reference manual is not
by accident (but: since each J dictionary entry contains
several examples, perhaps it is more accurately an
"illustrated dictionary"), and learning J from the J dictionary
is a lot like learning a natural language from a dictionary
of that language.
But no one is recommending that you learn J in this way.
The dictionary comes attached with an introduction,
with a topic per chapter, verbose description and deliberate
development, exercises, etc. If attempts at learning the
language by reading the dictionary meet with little success,
perhaps it is time to do as implied and recommended?
Go through the introduction (maybe even do the exercises).
As well, there has been available for some time the J Primer,
an introduction to the language for beginners. (All the books,
the Introduction, Dictionary, and Primer, are available as Windows
Helps and can be downloaded along with the J system from
The dictionary is not an introduction to the language. I should
say what I think it is:
The dictionary is a superb reference manual and detailed
blueprint for building an APL/J interpreter. It first saw the
light of day as "A Dictionary of the APL Language" (1985).
It went through many drafts and was circulated widely in the
APL community for comments and feedback, and was published as
"A Dictionary of APL" as an APL Quote-Quad issue (Sep 1987).
This is the version used to build the J interpreter
(Aug 1989). The current J dictionary is an evolution of
"A Dictionary of APL", and the organization, terminology, and
ideas can be clearly traced back to the very first version.
To the extent that the J system is coherent and consistent,
efficient and extensible, the major credit belongs to the