gistfile1.scm

(let (languages (make-eqv-hashtable))
  (define add-language (lambda (name func)
    (hashtable-set! languages name func)
  ))

  (define object (lambda (src)
    (let ((error (lambda () (fatal! "Unknown language src"))))
      ((hashtable-ref languages name error) src)
    )
  ))
)

(add-language ("c") (lambda (input)
  (let ((output (replace-ext input "o")))
    (actions (output) (input) (
      ((CC) -o (output) (input) (CFLAGS))
    ))
    (output)
  )
))

(add-language ("cpp" "cxx" "cc" "C") (lambda (input)
  (let ((output (replace-ext input "o")))
    (actions (output) (input) (
      ((CXX) -o (output) (input) (CFLAGS))
    ))
    (output)
  )
))

(define link (lambda (output objs)
  (actions (output) objs (
    ((LD) -o (output) (objs) (LDFLAGS) (LDLIBS))
  ))
))

(define objects (lambda (srcs))
  (if (null? srcs) 
    '()
    (cons (object (car srcs)) (objects (cdr srcs)))
  )
))

(define executable (lambda (output sources)
  (link output (objects sources))
))

# In the Makefile
(executable "hello" '("hello.c"))
(executable "hello++" '("hello++.cc"))