fix purcell#25 hook for post-processing formatter output

reformatter.el

@@ -76,14 +76,15 @@
  (require 'cl-lib))
 (require 'ansi-color)
 
-(defun reformatter--do-region (name beg end program args stdin stdout input-file exit-code-success-p display-errors)
+(defun reformatter--do-region (name beg end program args stdin stdout input-file exit-code-success-p output-processor display-errors)
  "Do the work of reformatter called NAME.
 Reformats the current buffer's region from BEG to END using
 PROGRAM and ARGS. For args STDIN, STDOUT, INPUT-FILE,
 EXIT-CODE-SUCCESS-P and DISPLAY-ERRORS see the documentation of
 the `reformatter-define' macro."
  (cl-assert input-file)
  (cl-assert (functionp exit-code-success-p))
+ (cl-assert (functionp output-processor))
  (when (and input-file
  (buffer-file-name)
  (string= (file-truename input-file)
@@ -119,9 +120,8 @@ the `reformatter-define' macro."
  ;; disruption to marker positions and the
  ;; undo list
  (narrow-to-region beg end)
- (reformatter-replace-buffer-contents-from-file (if stdout
- stdout-file
- input-file)))
+ (reformatter-replace-buffer-contents-from-file
+ (funcall output-processor (if stdout stdout-file input-file))))
  ;; If there are no errors then we hide the error buffer
  (delete-windows-on error-buffer))
  (if display-errors
@@ -131,7 +131,7 @@ the `reformatter-define' macro."
  (delete-file stdout-file))))
 
 ;;;###autoload
-(cl-defmacro reformatter-define (name &key program args (mode t) (stdin t) (stdout t) input-file lighter keymap group (exit-code-success-p 'zerop))
+(cl-defmacro reformatter-define (name &key program args (mode t) (stdin t) (stdout t) input-file lighter keymap group (exit-code-success-p 'zerop) (output-processor 'identity))
  "Define a reformatter command with NAME.
 
 When called, the reformatter will use PROGRAM and any ARGS to
@@ -222,10 +222,17 @@ EXIT-CODE-SUCCESS-P
  which accepts an integer process exit code, and returns non-nil
  if that exit code is considered successful. This could be a
  lambda, quoted symbol or sharp-quoted symbol. If not supplied,
- the code is considered successful if it is `zerop'."
+ the code is considered successful if it is `zerop'.
+
+OUTPUT-PROCESSOR
+
+ If provided, this is a function that takes the output PROGRAM,
+ do some arbitrary processing to it, and then return the final
+ output. If not supplied, the output is returned as is."
  (declare (indent defun))
  (cl-assert (symbolp name))
  (cl-assert (functionp exit-code-success-p))
+ (cl-assert (functionp output-processor))
  (cl-assert program)
  ;; Note: we skip using `gensym' here because the macro arguments are only
  ;; referred to once below, but this may have to change later.
@@ -271,7 +278,7 @@ DISPLAY-ERRORS, shows a buffer if the formatting fails."
  (reformatter--do-region
  ',name beg end
  ,program ,args ,stdin ,stdout input-file
- #',exit-code-success-p display-errors))
+ #',exit-code-success-p #',output-processor display-errors))
  (when (file-exists-p input-file)
  (delete-file input-file)))))