# A runtime variable hold a runtime value in C.
# Runtime variables are associated to Nit local variables and intermediate results in Nit expressions.
#
# The tricky point is that a single C variable can be associated to more than one `RuntimeVariable` because the static knowledge of the type of an expression can vary in the C code.
class RuntimeVariable
	# The name of the variable in the C code
	var name: String

	# The static type of the variable (as declard in C)
	var mtype: MType

	# The current casted type of the variable (as known in Nit)
	var mcasttype: MType is writable

	# If the variable exaclty a mcasttype?
	# false (usual value) means that the variable is a mcasttype or a subtype.
	var is_exact: Bool = false is writable

	init
	do
		assert not mtype.need_anchor
		assert not mcasttype.need_anchor
	end

	redef fun to_s do return name

	redef fun inspect
	do
		var exact_str
		if self.is_exact then
			exact_str = " exact"
		else
			exact_str = ""
		end
		var type_str
		if self.mtype == self.mcasttype then
			type_str = "{mtype}{exact_str}"
		else
			type_str = "{mtype}({mcasttype}{exact_str})"
		end
		return "<{name}:{type_str}>"
	end
end