BOUNCY language notes
3-DEC-2005


Program is a two-dimensional array of characters

PC consists of (X, Y, direction, mode)

direction is  (north, dsSouth, east, west)

mode is (normal,
	label,    -- after 'L' and before ':'
	return,   -- after ':' and before 'L'
	skip,     -- east/south:  after '(' and before next '('
                  -- west/north:  after ')' and before next ')'
	digit,    -- string of digits
	string)   -- between double quotes



space - normal: no operation (terminates digit entry)

| - east/west flow bounces 180 degrees, north/south flow passes unchanged

- - north/south flow bounces 180 degress, east/west flow passes unchanged

/ - bounce 90 degrees
    east flow turns north, south turns west, west turns south, north turns east

\ - bounce 90 degrees
    east flow turns south, south turns east, west turns north, north turns west

< - east bounces north or south depending on TOS
    north, south, bounces west
    west continues west

> - west bounces north or south depending on TOS
    north, south, bounces east
    east continues east

V - north bounces east or west depending on TOS
    east, west, bounces south
    south continues south

^ - south bounces east or west depending on TOS
    east, west, bounces north
    north continues north


(  east or south:  skip - ignores all chars until another '('
   west or north:  noop

)  west or north:  skip - ignores all chars until another ')'
   east or south:  noop

0-9 . - digit entry (all other characters terminate digit entry)

" - string entry - enter text mode, creates string on stack including characters through next "


a - add (concatenates strings)
s - subtract
m - multiply
d - divide
m - mod

= - compare

i - integer part
f - fractional part

u - dUp - duplicate TOS
r - dRop - discard TOS
w - sWap - exchange TOS with NOS

g - Get - save NOS in variable named by TOS
p - Put - get contents of variable named by TOS

G - Get array element
P - Put array element

t - prinT or Type
n - print Newline


L - label
	normal: enter label mode, which ignores digits until :
	return: return from subroutine


: - end label
	normal: switch to return mode
	label: switch to normal mode
 

J - jump to label (pops label number from stack) (disabled by default)


S - call subroutine (pops label number from stack)


Undefined:
+
?
;
!
@
#
$
%
&
*
_
[
]
{
}
~
`
,


Main program is subroutine at label 0.