(require-library srfi-1 matchable digraph format-graph test)
(import srfi-1 matchable digraph format-graph test)

(define used-by 
  (list 
    (cons 'dax_h 'foo_cpp) (cons 'dax_h 'bar_cpp) (cons 'dax_h 'yow_h)
    (cons 'yow_h 'bar_cpp) (cons 'yow_h 'zag_cpp) (cons 'boz_h 'bar_cpp)
    (cons 'boz_h 'zig_cpp) (cons 'boz_h 'zag_cpp) (cons 'zow_h 'foo_cpp)
    (cons 'foo_cpp 'foo_o) (cons 'foo_o 'libfoobar_a) 
    (cons 'bar_cpp 'bar_o) (cons 'bar_o 'libfoobar_a) 
    (cons 'libfoobar_a 'libzigzag_a) (cons 'zig_cpp 'zig_o) 
    (cons 'zig_o 'libzigzag_a) (cons 'zag_cpp 'zag_o) 
    (cons 'zag_o 'libzigzag_a) (cons 'libzigzag_a 'killerapp)))

(define g (make-digraph 'depgraph "dependency graph"))

(define node-list
  (delete-duplicates 
   (concatenate (list (map car used-by) (map cdr used-by)))))
	   
(define node-ids (list-tabulate (length node-list) values))

(for-each (lambda (i n) ((g 'add-node!) i n))
	  node-ids node-list)

(define node-map (zip node-list node-ids))

(for-each (lambda (e) 
	    (match e ((ni . nj) (let ((i (car (alist-ref ni node-map)))
				      (j (car (alist-ref nj node-map))))
				  ((g 'add-edge!) (list i j (format "~A->~A" ni nj)))))
		   (else (error "invalid edge " e))))
	  used-by)


((make-format-graph 'dot) (current-output-port) g )
((make-format-graph 'vcg) (current-output-port) g )