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emacs/lisp/ledger-mode/ledger-flymake.el
2025-02-26 20:16:44 +01:00

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EmacsLisp

;;; ledger-flymake.el --- A ledger Flymake backend -*- lexical-binding: t; -*-
;; Copyright (C) 2018 J. Alexander Branham (alex DOT branham AT gmail DOT com)
;; This file is not part of GNU Emacs.
;; This is free software; you can redistribute it and/or modify it under
;; the terms of the GNU General Public License as published by the Free
;; Software Foundation; either version 3, or (at your option) any later
;; version.
;;
;; This is distributed in the hope that it will be useful, but WITHOUT
;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
;; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
;; for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
;; MA 02110-1301 USA.
;;; Commentary:
;; Flymake is the built-in Emacs package to support on-the-fly syntax checking.
;; This file adds support for flymake to `ledger-mode'. Enable it by calling
;; `ledger-flymake-enable' from a file-visiting ledger buffer. To enable it
;; automatically, put this in your .emacs:
;;
;; (add-hook 'ledger-mode-hook #'ledger-flymake-enable)
;;; Code:
(require 'cl-lib)
(require 'flymake)
(require 'ledger-exec) ; for `ledger-binary-path'
(require 'ledger-report) ; for `ledger-master-file'
;; To silence byte compiler warnings in Emacs 25 and older:
(declare-function flymake-diag-region "flymake" (buffer line &optional col))
(declare-function flymake-make-diagnostic "flymake" (buffer beg end type text &optional data overlay-properties))
(defvar-local ledger--flymake-proc nil)
(defcustom ledger-flymake-be-pedantic nil
"If non-nil, pass the --pedantic flag for ledger to the flymake backend.
If --pedantic is in your ledgerrc file, then --pedantic gets
passed regardless of the value."
:type 'boolean
:package-version '(ledger-mode . "4.0.0")
:group 'ledger)
(defcustom ledger-flymake-be-explicit nil
"If non-nil, pass the --explicit flag for ledger to the flymake backend.
If --explicit is in your ledgerrc file, then --explicit gets
passed regardless of the value."
:type 'boolean
:package-version '(ledger-mode . "4.0.0")
:group 'ledger)
;; Based on the example from Flymake's info:
(defun ledger-flymake (report-fn &rest _args)
"A Flymake backend for `ledger-mode'.
Flymake calls this with REPORT-FN as needed."
(unless (executable-find ledger-binary-path)
(error "Cannot find ledger"))
;; If a live process launched in an earlier check was found, that
;; process is killed. When that process's sentinel eventually runs,
;; it will notice its obsoletion, since it have since reset
;; `ledger-flymake-proc' to a different value
(when (process-live-p ledger--flymake-proc)
(kill-process ledger--flymake-proc))
;; Save the current buffer, the narrowing restriction, remove any
;; narrowing restriction.
(let* ((source (current-buffer))
(file (or (ledger-master-file) (buffer-file-name))))
(save-restriction
(widen)
;; Reset the `ledger--flymake-proc' process to a new process
;; calling the ledger tool.
(setq
ledger--flymake-proc
(make-process
:name "ledger-flymake" :noquery t :connection-type 'pipe
:buffer (generate-new-buffer " *ledger-flymake*")
:command (cl-remove
nil
`(,ledger-binary-path "-f" ,file
,(when ledger-flymake-be-pedantic "--pedantic")
,(when ledger-flymake-be-explicit "--explicit")
"balance"))
:sentinel
(lambda (proc _event)
;; Check that the process has indeed exited, as it might
;; be simply suspended.
(when (eq 'exit (process-status proc))
(unwind-protect
;; Only proceed if `proc' is the same as
;; `ledger--flymake-proc', which indicates that
;; `proc' is not an obsolete process.
(if (with-current-buffer source (eq proc ledger--flymake-proc))
(with-current-buffer (process-buffer proc)
(goto-char (point-min))
;; Parse the output buffer for diagnostic's
;; messages and locations, collect them in a list
;; of objects, and call `report-fn'.
(cl-loop
while (search-forward-regexp
;; This regex needs to match the whole error. We
;; also need a capture group for the error message
;; (that's group 1 here) and the line number
;; (group 2).
(rx line-start "While parsing file \"" (one-or-more (not whitespace)) " line " (group-n 2 (one-or-more num)) ":\n"
(zero-or-more line-start "While " (one-or-more not-newline) "\n" )
(minimal-match (zero-or-more line-start (zero-or-more not-newline) "\n"))
(group-n 1 "Error: " (one-or-more not-newline) "\n"))
nil t)
for msg = (match-string 1)
for (beg . end) = (flymake-diag-region
source
(string-to-number (match-string 2)))
for type = :error
collect (flymake-make-diagnostic source
beg
end
type
msg)
into diags
finally (funcall report-fn diags)))
(flymake-log :warning "Canceling obsolete check %s"
proc))
;; Cleanup the temporary buffer used to hold the
;; check's output.
(kill-buffer (process-buffer proc))))))))))
;;;###autoload
(defun ledger-flymake-enable ()
"Enable `flymake-mode' in `ledger-mode' buffers."
(unless (> emacs-major-version 25)
(error "Ledger-flymake requires Emacs version 26 or higher"))
;; Add `ledger-flymake' to `flymake-diagnostic-functions' so that flymake can
;; work in ledger-mode:
(add-hook 'flymake-diagnostic-functions 'ledger-flymake nil t)
(flymake-mode))
(provide 'ledger-flymake)
;;; ledger-flymake.el ends here