Notes on Fast Function Compiler, by Doug Houck, programmer


The Fast Function Compiler creates native-code functions which are called
directly by the program.  It uses a precedence parsing technique so ()s are
needed only to change the normal precedence.  The predence of operators is
given below from highest to lowest.

  Named functions, eg. sin(), fa2(), min()
  not, unary minus
  ^ (exponentiation)
  * / % mod
  +, -
  >, <, >=, <=,
  ==, !=, <>,
  and
  xor
  or
  ? : (if-else)
  ,  (comma)

Sometimes the compiler cannot figure out what you mean.  Then it gives you
one of the following messages at the bottom of the screen.

  Too Many Operations Pending
  Functions Too Large
    You should not get these errors, but if you do, simplify your function,
    and report the error.

  Unknown Function
    The compiler expected a function from the function list.  (See Functions
    in the Info menu)  Either you misspelled it, were daydreaming about some
    other programming language, or you put in an unknown character.  For
    example, you must spell out 'and,', not just put &.  Note that function
    names must be delimited by a space, ), or something.

  Extra )
  Missing )
    Your parentheses must balance.  Otherwise the compiler would not be sure
    what you meant.

  Not Enough Operands / Too Many Operators
  Too Many Operands / Not Enough Operators
    When the compiler got to this point, it realized it had a situation like
    '3+2+'  or '3+2 4'.  In the first example, it doesn't know what to do with
    the second plus sign.  In the second example, compiler can't use the 4.
    PLEASE NOTE that the error is usually a ways back, NOT where the cursor
    is.

  : Must Follow ?
    In using the if-else statement, each if (?) MUST be paired with an else
    (:).  If you are nesting ifs, putting a '+0' before the ':' may help.
    (compiler deficiency)

  Missing :
    Make sure you complete the ?: pair.

  No Value For Argument
    A1,a2,a3, and a4 are generic names for the values you pass to functions
    fa,fb,fc or fd.  If you call a function with 3 values (ie. fb3(1,2,3) )
    you may reference only arguments a1 through a3.  (a4 would be garbage)
    If you are not using the function this error occurs in, delete it. 


  Recursion is supported by the Fast Function Compiler.  All passed values
and intermediate values are stored on the execution stack, so each new
invocation of a function gets it's own space.  Variables A-Z are global.
When the bottom of the process stack is reached, it returns a value of zero
for the function.   To increase the recursion stack, execute the CLI command
STACK to set the stack size to a larger value before running Doug's Math 
Aquarium.