[elpa] externals/relint 6a86509 10/11: Tuned miscape filtering

[Mattias Engdegård]

branch: externals/relint
commit 6a865096791757c0034238f813910b87018a0e31
Author: Mattias Engdegård <mattiase@acm.org>
Commit: Mattias Engdegård <mattiase@acm.org>

    Tuned miscape filtering
    
    Instead of disabling the useless backslash check for all doc strings,
    just ignore escaped ()[]' -- round and square brackets and apostrophe.
    This catches more actual mistakes while avoiding most false positives.
---
 relint.el        | 13 ++++---------
 test/13.elisp    | 13 +++++++------
 test/13.expected | 38 ++++++++++++++++++++++++--------------
 3 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/relint.el b/relint.el
index 3c6d05a..5124958 100644
--- a/relint.el
+++ b/relint.el
@@ -2164,20 +2164,15 @@ Return a list of (FORM . STARTING-POSITION)."
        (and (= steps 4)
             (looking-at (rx (or "define-derived-mode"))))))))
 
-(defconst relint--miscape-ignore-left-round-bracket nil
-  "Whether to ignore specifically `\\(' in doc strings.")
-
-(defconst relint--miscape-ignore-all-doc-strings t
-  "Whether to ignore all stray backslashes in doc strings.")
-
 (defun relint--suspicious-backslash (string-start)
   "With point at an ineffective backslash, emit an warning unless filtered out.
 STRING-START is the start of the string literal (first double quote)."
   (let ((c (char-after (1+ (point)))))
+    ;; Filter out escaped round and square brackets and apostrophes
+    ;; inside doc strings, as well as anything in the leftmost column:
+    ;; common for historical reasons and less likely to be mistakes.
     (unless (or (bolp)
-                (and (or (and relint--miscape-ignore-left-round-bracket
-                              (eq c ?\())
-                         relint--miscape-ignore-all-doc-strings)
+                (and (memq c '(?\( ?\) ?\[ ?\] ?\'))
                      (relint--in-doc-string-p string-start)))
       (relint--warn (point) nil
                     (format-message
diff --git a/test/13.elisp b/test/13.elisp
index 58c1609..1f8cb58 100644
--- a/test/13.elisp
+++ b/test/13.elisp
@@ -3,13 +3,14 @@
 ;; Test ineffective backslashes in strings
 
 (defun f1 ()
-  "doc string with \(silly\) bac\kslashes
-\[that we ignore\]"
+  "doc string:
+\! \( \) \[ \] \' all ignored
+not ignored: \{ \} \| \` \? \* \. \+ \; \q etc"
   (list
-   "\more \(bad things\)"
-   "long \<string\>
-\(with mistakes\)
-\{and so on\}"
+   "\more"
+   "not ignored: \( \) \[ \] \'"
+   "long string \;
+\; and so on"
    "valid: \\ \" \x5e \172 \u1234 \u00000041 \C-x \M-e \ \
 and \a \b \f \n \r \t \v \d \e \s \^P"))
 
diff --git a/test/13.expected b/test/13.expected
index 8c721d5..53a4568 100644
--- a/test/13.expected
+++ b/test/13.expected
@@ -1,18 +1,28 @@
-13.elisp:9:5: Ineffective string escape `\m'
-13.elisp:9:11: Ineffective string escape `\('
-13.elisp:9:23: Ineffective string escape `\)'
-13.elisp:10:10: Ineffective string escape `\<'
-13.elisp:10:18: Ineffective string escape `\>'
-13.elisp:11:16: Ineffective string escape `\)'
-13.elisp:12:12: Ineffective string escape `\}'
-13.elisp:17:23: In call to re-search-forward: Unescaped literal `$' (pos 0)
+13.elisp:8:14: Ineffective string escape `\{'
+13.elisp:8:17: Ineffective string escape `\}'
+13.elisp:8:20: Ineffective string escape `\|'
+13.elisp:8:23: Ineffective string escape `\`'
+13.elisp:8:26: Ineffective string escape `\?'
+13.elisp:8:29: Ineffective string escape `\*'
+13.elisp:8:32: Ineffective string escape `\.'
+13.elisp:8:35: Ineffective string escape `\+'
+13.elisp:8:38: Ineffective string escape `\;'
+13.elisp:8:41: Ineffective string escape `\q'
+13.elisp:10:5: Ineffective string escape `\m'
+13.elisp:11:18: Ineffective string escape `\('
+13.elisp:11:21: Ineffective string escape `\)'
+13.elisp:11:24: Ineffective string escape `\['
+13.elisp:11:27: Ineffective string escape `\]'
+13.elisp:11:30: Ineffective string escape `\''
+13.elisp:12:17: Ineffective string escape `\;'
+13.elisp:18:23: In call to re-search-forward: Unescaped literal `$' (pos 0)
   "$.x++"
    ^
-13.elisp:17:23: Ineffective string escape `\$'
-13.elisp:17:25: Ineffective string escape `\.'
-13.elisp:17:28: Ineffective string escape `\+'
-13.elisp:17:30: In call to re-search-forward: Repetition of repetition (pos 4)
+13.elisp:18:23: Ineffective string escape `\$'
+13.elisp:18:25: Ineffective string escape `\.'
+13.elisp:18:28: Ineffective string escape `\+'
+13.elisp:18:30: In call to re-search-forward: Repetition of repetition (pos 4)
   "$.x++"
    ....^
-13.elisp:17:30: Ineffective string escape `\+'
-13.elisp:18:16: Ineffective string escape `\q'
+13.elisp:18:30: Ineffective string escape `\+'
+13.elisp:19:16: Ineffective string escape `\q'