anchor.diff:      (format *error-output* "~&ready> ")
       (get-next-token)
       (main-loop)
  -    (llvm:dump-module *module*)))+    (llvm:dump-module *module*)))
  
positive.code: 
  (defclass number-expression (expression)
    ((value :initarg :value :reader value))
    (:documentation "Expression class for numeric literals like \"1.0\"."))
  
  (defclass variable-expression (expression)
    ((name :initarg :name :reader name))
    (:documentation "Expression class for referencing a variable, like \"a\"."))
  
  (defclass unary-expression (expression)
    ((opcode :initarg :opcode :reader opcode)
  
negative.code:   ((condition :initarg :condition :reader condition)
     (then :initarg :then :reader then)
     (else :initarg :else :reader else))
    (:documentation "Expression class for if/then/else."))
  
  (defclass for-expression (expression)
    ((var-name :initarg :var-name :reader var-name)
  