COP 4620 - Programming Language Translators


               Project Zero - Getting Started


Project 0 consists of getting familiarized  with  the  Tiny
Compiler/Interpreter from the language user's point of view,
i.e as a Tiny programmer.   In your Tiny directory there are
are number of files, briefly explained as follows:


CodeGenerator.c: This is the source file for the code gener-
ator.  More on this creature later.


Constrainer.c:  This  is  the source file for the contextual
constrainer.  More on this later.


lex.tiny, parse.tiny. These are lexical and parsing specifi-
cations  for  Tiny.  The only one that matters at this point
is "parse.tiny".  It describes Tiny's syntax.   You'll  need
it for this assignment.


Constrain, CodeGen: These are the ready-to-run compiler com-
ponents.


tests/p1, p2, p3, p4, p5, p6, p7: Seven test programs, writ-
ten in Tiny.


tc:   This  is  the Tiny Compiler/Interpreter.  It's nothing
more than a shell script, that invokes  the  scanner/parser,
then  the  constrainer, then the code generator, and finally
the interpreter.  As these as executed, their effect  is  as
follows:

1)   The  parser  produces a file called _TREE, in your cur-
     rent directory (typically the 'tiny' directory).

2)   The constrainer reads in the _TREE file, traverses  the
     tree,  adds  constraining information to it, and writes
     it back out.

3)   The code generator reads in the tree, traverses  it  to
     generate code, and produces a file called _CODE in your
     current directory.  It also updates the new  (slightly)
     modified tree.

4)   The  interpreter reads in the _CODE file, and simulates
     the execution of the program in it.

The sooner you learn to read target code files, the  better.
Some  documentation files are available in
{your_path}/tws/manual.
They are:


                    abs_machine
                    code_generator
                    constrainer
                    dcln_module
                    parse
                    pgen
                    print_tree
                    text_table
                    tree_module


Your assignment zero consists of writing, coding,  and  run-
ning a single Tiny program.  The Tiny program should take as
input two positive numbers N and M, and print the product of
all  numbers  between  N and M, i.e. N*(N+1)*(N+2)*...*M, if
N<=M, or the other way around, if N>M.  In coding  the  pro-
gram,  you  should  keep in mind that you are dealing with a
very small language.  As you can see in the parser  specifi-
cation  (in  parse.tiny),  Tiny has a very limited number of
operators.  There is no division, no subtraction, no  multi-
plication,  no  comparison  operators  other  than "<=", and
although boolean  variables  can  be  declared,  the  values
"true"  and  "false"  are nonexistent.  You must work around
these limitations.    A good way to see how things are  done
in  Tiny is to mimic existing programs.  Taking a look at p1
through p7 is a good idea, especially p4, which is a  facto-
rial program.

     This first assignment (and the second one) MUST be done
individually.  

The  deadline for  this  assignment is  Friday,  August 31.
No paper needs to be handed in  in  class.   Send your Tiny
program  (a text file)  as  an  email  attachment  to  your
professor's email address: manuel@cise.ufl.edu.