anchor.diff:                ("-x~a" source)
                 ("-std=~a" standard)
                 ("-Wl~{,~a~}" options)
  -              ("~{-Xlinker ~a~^ ~}" arguments)
                 ("-shared~*" shared)
                 ("-o ~a" to)
                 ("~:[~a~;~{~a~^ ~}~]" (listp from) from)))))
  
positive.code:                                                  debug
                                                   source
                                                   standard
                                                   options
                                                   arguments)
      (invoke c-compiler
              (shellify
                ("-c~*" T)
  
negative.code:              ("-x~a" source)
               ("-std=~a" standard)
               ("-Wp~{,~a~}" options)
               ("-o ~a" to)
               ("~a" from)))))
  
  