[CSCI2321] Cleaning up your J files in your copy of cs2321

[John Howland]

I have had to make a number of changes in our J files which model
various aspects of computer architecture.  These changes are mandated
by changes in the J standard library since the last time I taught this
course (2001) and also by the fact that even though the J language predates
Java, its use of .js as an extension for J files was ignored by the Java
community.  Hence, the J community has adopted the convention of using
.ijs as an extension for J script files (the i is in honor of Dr. Kenneth Iverson).

You should clean up your cs2321 directory by executing the following commands
after logging into one of our Unix (Linux) client machines.

1)  change to your cs2321 directory

cd cs2321

2)  remove the j shell script which is used to start j
    and all .js files and all .ijs files

rm j *.js *.ijs

3)  copy a new j script and the new .ijs files for our course

cp ~jhowland/cs2321/j  ~jhowland/cs2321/*.ijs  ./

You should do this before class tomorrow so that you can use J
during the lecture so that you can follow what we do during the
lecture.

Many of the changes accomplished above are subtle, but three obvious
differences are that code which used to read

foo =: monad define script
...
)

is changed to

foo =: monad define
...
)

because define has changed from ":" to ":0"

and a new definiton of 

def =: :

has been introduced.

Finally, script is no longer "0", but rather it is now a function

   script
[: 3 : '0!:0 y.' jpath_z_&.:>

I apologize for the minor disruption these changes may cause, but
making the change does not change the readability of our models and
will make our future definitions compatible with the J standard
library conventions.


-- 
_______________________________________________________________
John E. Howland       url: http://www.cs.trinity.edu/~jhowland/
Computer Science    email: jhowland at ariel.cs.trinity.edu
Trinity University  voice: (210) 999-7364
One Trinity Place     fax: (210) 999-7477
San Antonio, Texas  78212-7200