redef class Variable
	# The declared type of the variable
	var declared_type: nullable MType = null is writable

	# Was the variable type-adapted?
	# This is used to speedup type retrieval while it remains `false`
	private var is_adapted = false
end

redef class Variable
	# The expressions of AST of this variable depends
	var dep_exprs = new Array[AExpr]

	# The blocks in which this variable is assigned
	var assignment_blocks: Array[BasicBlock] = new Array[BasicBlock] is lazy

	# Part of the program where this variable is read
	var read_blocks: Array[BasicBlock] = new Array[BasicBlock] is lazy

	# The stack of this variable, used for SSA renaming
	var stack = new Array[Variable] is lazy

	# The original Variable in case of renaming
	var original_variable: nullable Variable = self

	# If true, this variable is a parameter of a method
	var parameter: Bool = false
end

redef class Variable
	# The position in the environment
	var position: Int is writable
end

redef class Variable
	super HInfoBoxable
	redef fun infobox(v)
	do
		var declared_type = self.declared_type
		if declared_type == null then
			var res = new HInfoBox(v, "{name}")
			res.new_field("local var").append("{name}")
			return res
		end
		var res = new HInfoBox(v, "{name}: {declared_type}")
		res.new_field("local var").append("{name}:").add(declared_type.linkto(v))
		return res
	end
end