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Question 2 (50%)

Create your own more advanced
interpreted programming language called MYPL.
You must do this using the already written TLM
as a base. In other words starting from the components
of TLM, build up your own language and interpreter.
Your language must have the following enhancements:


Boolean expressions in TLM only have one
operator: \>". Build into MYPL the use of more
boolean operators such as <, ==, =< etc.


Build into MYPL the statement
\if < booleanexpression > then < statement1 >
else < statement2 >"

with the usual meaning.


Build into MYPL a simple function declaration structure.
For the sake of this coursework, your implementation of a
function can be as follows:


Only one function can be declared and it must
be declared at the beginning of the program.


The function has no name or parameters.


All the variables used in the function are global.


The function is called by the statement \call", and it
can be called as many times as needed in the main
part of the program. For example, MYPL should be able
to execute the following code:
start;
function;
do
x = x-1;
y = x*x;
print(x,y);
while x > 10 ;
end;
x = 23; call; x=15; call;
finish;


Enhance MYPL further - for example
by making the function feature more general (e.g.
with more that one function being declared).
You may also add any other useful features to MYPL
(e.g. add a FOR loop, add more variable names,
add the ability to write comments in the program,
make MYPL check the whole of a keyword etc).


Rules

This coursework must be undertaken
individually. The deadline for handing in the work
is 4pm Wednesday April 10th, 2019.


You must hand in for question 1:

The grammar
Derivation sequence syntax tree
Derived FSM
Derived shift-reduce parsing table
Proof using a stack trace that the correct example is parsed
and the incorrect example does not parse.

YOUR SOLUTION TO QUESTION 1 MUST BE A HARD COPY
HANDED IN TO THE STUDENT SUPPORT
OFFICE BY HAND.


You must hand in for question 2:


The two les parser.cup and scanner.java dening
your nal language. This must allow me to generate
an interpreter using JavaCup and validate your tests.


Several test programs and screen shots of their
execution showing the use of ALL the new features
in your language and showing the correctness
of your code. If you do not include tests with
associated screen shots of the new features of
MYPL, they will be assumed not to work,


A written report including the following: a statement
of what you have achieved in Question 2; and
documentation describing HOW you have upgraded TLM for
Question 2.
Here you must
explain in your own words how the code you have
added to TLM works, any decisions of it, and
any future extensions you could achieve given more
time.
YOUR SOLUTION TO QUESTION 1 MUST
BE HANDED IN ELECTRONICALLY VIA
BRIGHTSPACE.


Marking Criteria and Scheme: The coursework
assesses the following ability outcomes of the module:
*
Knowledge (4) and (5), Ability (8). It also, in
part, examines outcome Ablity (6). It makes up 50
per cent of your 20 credit module.
*
QUESTION 1 Criteria: Correctness of your gram-
mar, FSM, parsing table, stack trace of the example
parse and documentation.
Marking Scheme:
  1: (8%); 
  2: (10%);
  3: (24%);
  4: (8%); 


To pass

You must at least demonstrated
you can create a grammar and translate it into a
FSM and then a parsing table, though you may
have made some major mistakes.


Over 50%
Your parsing table creation is faithful
with respect to the grammar you produce, (there
may be S-R conflicts, and some errors, but the
method is sound) and you have made a reasonable
attempt at generating a stack trace of the example
parse and counter-example.


Over 60%
As above, but your grammar is correct,
your parsing table is created correctly with respect
to the grammar but may have S-R conflicts. You may have
some minor errors.


Over 70%
As above, but your grammar is correct
and leads to a conflict free parsing table. You may
have some minor errors.


Over 85%
Your grammar is correct