algebrite/runtime/count.coffee

Computer Algebra System in Coffeescript

count = (p) ->
	if (iscons(p))
		n = 0
		while (iscons(p))
			n += count(car(p)) + 1
			p = cdr(p)
	else
		n = 1
	return n

# this probably works out to be
# more general than just counting symbols, it can
# probably count instances of anything you pass as
# first argument but didn't try it.
countOccurrencesOfSymbol = (needle,p) ->
	n = 0
	if (iscons(p))
		while (iscons(p))
			n += countOccurrencesOfSymbol(needle,car(p))
			p = cdr(p)
	else
		if equal(needle,p)
			n = 1
	return n


# returns the total number of elements
# in an expression
countsize = (p) ->
	n = 0

	if (istensor(p))
		for i in [0...p.tensor.nelem]
			n += p.tensor.elem[i]
	else if (iscons(p))
		while (iscons(p))
			n += count(car(p)) + 1
			p = cdr(p)
	else
		n = 1

	return n