BABBAGE THE NEW LANGUAGE FOR FUTURE DEMANDS


















REPORT No : 1-4:25.1

FROM THE BABBAGE LANGUAGE DESIGN GROUP
SEPTEMBER 1984






























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BABBAGE
THE LANGUAGE OF THE FUTURE



There are few things in this business that are more fun than designing a
new computer language, and the very latest is ADA - the Department of
Defence's new supertoy. ADA as you know, has been designed to replace
outmoded and obsolete languages such as COBOL and FORTRAN.

The problem is that this cycle takes 20 to 30 years and doesn't start until
we're really convinced present languages are no good. We can short-circuit
this process by starting on Ada's replacement right now. Then by the time
we decide Ada is obsolete, it's replacement will be ready.

The new generation of language designers has taken to its brainchildren
after real people rather than resorting to the usual acronyms. Pascal
is named after the first person to build a calculating machine and ADA is
named after the first computer programmer. As our namesake, we chose
Charles Babbage, who died while trying to finish building the first
computer. The new language is thus named after the first systems designer
to go over budget and behind schedule.

Babbage is based on language elements that were discovered after the design
of Ada was completed. For instance, C.A.R Hoare, in his 1930 ACM Turing
Award lecture, told of two ways of constructing a software design : " one
way is to make it so simple that there are obviously no deficiences and the
other is to make it so complicated that there are no obvious deficiences."
The designer's of Babbage have chosen a third alternative -
a language that has only obvious deficiences. Babbage programs are so
unreliable that maintenance can begin before system integration is
completed. This guarantees a steady increase in the DP job marketplace.

Like Pascal, Ada uses "strong typing" to avoid errors caused by mixing data
types. The designers of Babbage advocate "good typing" to avoid errors
caused by misspelling the words in your program. Later versions of Babbage
will also allow "touch typing", which will fill a long-felt need.

A hotly contested issue among language designers is the method for passing
parameters to subfunctions. Some advocate "call by name", other's prefer
"call by value". Babbage uses a new method - "call by telephone". This is
especially effective for long-distance parameter passing.

Ada stresses the concept of software portability. Babbage encourage
hardware portability. After all, what good is a computer if you can't take
it with you? It's a good sign if your language is sponsored by the
government. COBOL had goverment backing, and Ada is being founded by the
Departement of Defence. After much negotiation, the Departement of Defence
of Sanitation has agreed to sponsor Babbage.

No subset of Ada are allowed. Babbage is just the opposite. None of Babbage
is defined except it's extensibility - each user must define his own version.
To end the debate of large languages versus small, Babbage allows each
user to make the language any size he wants. Babbage is the ideal language
for the "me" generation. The examples that follow will give some idea of
what Babbage looks like.






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STRUCTURES:



Structured languages banned GOTO:s and multiway conditional branches by
replacing them with the simpler IF-THEN-ELSE structure. Babbage has a
number of new conditional statements that act like termites in the
structure of your program:


WHAT IF - Used in simulation languages. Branch before evaluation
of test conditions.

OR ELSE - Conditional threat, as in: "Add these two numbers OR ELSE!"

WHY NOT - Executes the code that follows in a devil-may-care fashion.

WHO ELSE - Used for polling during I/O operations.

ELSEWHERE - This is where your program really is when you think it's here.

GOING GOING GONE - For writing unstructured programs. Takes a random branch to
another part of your program. Does the work for 10 GOTOs.



For years, programming languages have used "FOR", "DO UNTIL", "DO WHILE",
etc. to mean "LOOP". Continuing with this trend, Babbage offers the
following loop statements:


DON'T DO WHILE NOT - This loop is not executed if the test condition is
not false (or of it's Friday afternoon).

DIDN'T DO - The loop executes once and hides all traces.

CAN'T DO - The loop is pooped.

WON'T DO - The CPU halts because it doesn't like the code inside the
loop. Execution can be resumed by typing "May I" at the
console.

MIGHT DO - Depends on how the CPU is feeling. Executed if the CPU is
"up", not executed if the CPU is "down" or if its feelings
have been hurt.

DO UNTIL OTHERS - Used to write the main loop for timesharing systems so
that they will antagonize the users in a uniform manner.

DO-WAH - Used to write timing loops for computer-generated-music
(Rag-timing).










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MULTIWAY BRANCHES:



Every self-respecting structured language has a case statement to implement
multiway branching. ALGOL offers an index case statement and Pascal has a
labled case statement. Not much of a choice. Babbage offers a variety of
case statements:




* The JUST-IN-CASE statement.
For handling afterthoughts and fudge factors. Allow you to
multiply by zero to correct for accidentally dividing by zero.

* The BRIEF CASE statement
To ensure portable software.

* The OPEN-AND-SHUT CASE statement.
No proof of correctness is neccessary with this one.

* The IN-ANY-CASE statement.
This one newer works.

* The HOPELESS CASE statement.
This one never works.

* The BASKET CASE statement.
A really hopeless case.






The Babbage language Design Group is continously evaluating new features
that will keep users from reaching any level of effectiveness. For
instance, Babbage's designers are now considering the ALMOST EQUALS SIGN,
used for comparing two floating point numbers. This new feature "takes the
worry out of being close".




















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THE OPERATING SYSTEM:



No language, no matter how bad, can stand on its own. We need a really
state-of-the-art operating system to support Babbage. After trying several
commercial systems, we decided to try write a "virtual" operating system.
Everybody has a virtual memory operating system so we decided to try
something a little different. Our new operating system is called the
Virtual Time Operating System (VTOS). While virtual memory systems make the
computers memory the virtual resource, VTOS does the same thing with CPU
process time.

The result is that the computer can run a unlimited number of jobs at the
same time. Like the Virtual memory system, which actually keeps part of the
memory on disk, VTOS has to play tricks to achieve its goals. Although all
of your jobs seem to be running right now, some of them are actually
running next week.

As you see, Babbage is still in its infancy. The Babbage Language Design
Group is seeking suggestions for this powerful new language and as the sole
member of this group (all applications for membership will be accepted ).
I call on the data processing community for help in making this dream a
reallity.






- Tony Karp
Jamaica, New York





























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