scheme-find-definition

[Kalle Olavi Niemitalo <tosi at stekt dot oulu dot fi>]

Here's a command which finds the source location of a Scheme
procedure, if the reader saved it.  (read-enable 'positions)
I didn't commit this to CVS because Keisuke is rewriting the
Scheme files.  Will that take long?

(import-lisp-function find-file)
(import-lisp-function goto-line)
(import-lisp-function move-to-column)

(define (find-filename-property tree)
  "Return a part of TREE which has a `filename' source-property.
Return #f if not found."
  (and (pair? tree)
       (or (and (source-property tree 'filename) tree)
	   (find-filename-property (car tree))
	   (find-filename-property (cdr tree)))))

(define-command (scheme-find-procedure proc)
  "Go to the definition of Scheme procedure PROC."
  (interactive "SFind procedure: ")
  ;; Hack for converting interactively entered symbols to procedures.
  ;; This might go away, don't use this from programs.
  (if (symbol? proc) (set! proc (eval proc)))
  (let ((part (cond ((procedure-with-setter? proc)
		     (or (find-filename-property (procedure-source (procedure proc)))
			   (find-filename-property (procedure-source (setter proc)))))
		    ((procedure? proc)
		     (find-filename-property (procedure-source proc))))))
    (or part (error "Can't find definition of " proc))
    (find-file (source-property part 'filename))
    (and=> (source-property part 'line)
	   (lambda (line) (goto-line (+ line 1))))
    (and=> (source-property part 'column) move-to-column)))