Const = Struct.new(:loc, :type, :value)
Var = Struct.new(:loc, :type, :name)
EnvRef = Struct.new(:loc, :type, :index)
Const = Struct.new(:loc, :type, :value)
Var = Struct.new(:loc, :type, :name)
EnvRef = Struct.new(:loc, :type, :index)
Let = Struct.new(:loc, :type, :var, :expr, :body)
If = Struct.new(:loc, :type, :cond, :then, :else)
Set = Struct.new(:loc, :type, :var, :expr)
Let = Struct.new(:loc, :type, :var, :expr, :body)
If = Struct.new(:loc, :type, :cond, :then, :else)
Set = Struct.new(:loc, :type, :var, :expr)