Improve readability of the error message

[gnu-emacs-elpa] / validate.el

diff --git a/validate.el b/validate.el
index 1ded67b0dd49d6d12572a1edcc1d54130ef7e1d6..2d66a2785026f94ecaffed3675a1f1a4d5d860e0 100644 (file)
--- a/validate.el
+++ b/validate.el
@@ -1,11 +1,11 @@
 ;;; validate.el --- Schema validation for Emacs-lisp  -*- lexical-binding: t; -*-
 
-;; Copyright (C) 2016  Artur Malabarba
+;; Copyright (C) 2016  Free Software Foundation, Inc.
 
 ;; Author: Artur Malabarba <emacs@endlessparentheses.com>
 ;; Keywords: lisp
 ;; Package-Requires: ((emacs "24.1") (cl-lib "0.5"))
-;; Version: 0.1
+;; Version: 0.3
 
 ;;; Commentary:
 ;;
@@ -64,6 +64,9 @@
       "wrong number of elements"
     (seq-find #'identity (seq-mapn #'validate--check values schemas))))
 
+(defun validate--indent-by-2 (x)
+  (replace-regexp-in-string "^" "  " x))
+
 (defun validate--check (value schema)
   "Return nil if VALUE matches SCHEMA.
 If they don't match, return an explanation."
@@ -127,8 +130,8 @@ If they don't match, return an explanation."
                                    (error "`choice' needs at least one argument")
                                  (let ((gather (mapcar (lambda (x) (validate--check value x)) args)))
                                    (when (seq-every-p #'identity gather)
-                                     (concat "all of the options failed\n  "
-                                             (mapconcat #'identity gather "\n  "))))))
+                                     (concat "all of the options failed\n"
+                                             (mapconcat #'validate--indent-by-2 gather "\n"))))))
                ;; TODO: `restricted-sexp'
                (set (or (wtype 'list)
                         (let ((failed (list t)))
@@ -145,7 +148,10 @@ If they don't match, return an explanation."
         (let ((print-length 4)
               (print-level 2))
           (format "Looking for `%S' in `%S' failed because:\n%s"
-                  schema value r))))))
+                  schema value
+                  (if (string-match "\\`Looking" r)
+                      r
+                    (validate--indent-by-2 r))))))))
 
 \f
 ;;; Exposed API
@@ -175,5 +181,17 @@ with `validate-value'. NOERROR is passed to `validate-value'."
       (if noerror val
         (error "Variable `%s' has no custom-type." symbol)))))
 
+;;;###autoload
+(defun validate-mark-safe-local (symbol)
+  "Mark SYMBOL as a safe local if its custom type is obeyed."
+  (put symbol 'safe-local-variable
+       (lambda (val)
+         (validate-value val (custom-variable-type symbol) 'noerror))))
+
+(defmacro validate-setq (symbol value)
+  "Like `setq', but throw an error if validation fails.
+VALUE is validated against SYMBOL's custom type."
+  `(setq ,symbol (validate-value ,value (custom-variable-type ',symbol))))
+
 (provide 'validate)
 ;;; validate.el ends here