# HelperRules
#
# Helper rules without side effects.

rule FFilter
{
	# FFilter <list> : <excludes> ;
	#
	# Removes all occurrences of <excludes> in <list>.

	local list = $(1) ;
	local excludes = $(2) ;
	local newList ;
	local item ;
	for item in $(list) {
		local skip ;
		local exclude ;
		for exclude in $(excludes) {
			if $(item) = $(exclude) {
				skip = true ;
			}
		}
		if ! $(skip) {
			newList += $(item) ;
		}
	}
	return $(newList) ;
}

rule FSplitPath
{
	# FSplitPath <path> ;
	#
	# Decomposes a path into its components.
	#
	# <path>: The path to be decomposed.
	#
	local path = $(1:G=) ;

	local components ;
	# $(path:D) for "/" is "/". Therefore the second condition.
	while $(path:D) && $(path:D) != $(path)
	{
		# Note: $(path:B) returns "." for "..", but $(path:D=) is fine.
		components = $(path:D=) $(components) ;
		path = $(path:D) ;
	}
	components = $(components) ;
	# Use this to return initial /
	#components = $(path) $(components) ;
	return $(components) ;
}