algebrite/sources/factors.coffee

Computer Algebra System in Coffeescript

# Push expression factors onto the stack. For example...
#
# Input
#
#       2
#     3x  + 2x + 1
#
# Output on stack
#
#     [  3  ]
#     [ x^2 ]
#     [  2  ]
#     [  x  ]
#     [  1  ]
#
# but not necessarily in that order. Returns the number of factors.



# Local U *p is OK here because no functional path to garbage collector.

factors = (p) ->
	h = tos
	if (car(p) == symbol(ADD))
		p = cdr(p)
		while (iscons(p))
			push_term_factors(car(p))
			p = cdr(p)
	else
		push_term_factors(p)
	return tos - h

# Local U *p is OK here because no functional path to garbage collector.

push_term_factors = (p) ->
	if (car(p) == symbol(MULTIPLY))
		p = cdr(p)
		while (iscons(p))
			push(car(p))
			p = cdr(p)
	else
		push(p)