To install this package, run in Emacs:
M-x package-install RET flylisp RET
Colors mismatched open parentheses with fl-mismatched-face, red by default. Works reliably after Emacs 24.3, in which bug 16247 is fixed. Also colors open and close parentheses which are inconsistent with the indentation of lines between them with fl-inconsistent-face, orange by default. This is useful for the Lisp programmer who infers a close paren's location from the open paren and indentation. The coloring serves as a warning that the indentation misleads about where the close paren is. It may also help to localize the mistake, whether due to a misindented line or a misplaced paren. As an example, consider: (aaa (bbb "word-a word-b" (ccc 1 2) fff)) (aaa ...) and (ccc ...) are consistent, so are not colored. (bbb ...) is inconsistent because the indentation of fff is inconsistent with the actual location of the close paren. The open and close paren are thus colored with the fl-inconsistent-face. This example also shows that multi line strings don't cause an inconsistency. Currently, the package only detects close parens that are after the place indentation would predict. A planned feature is to also indicate when the close paren is before. Also planned is to color mismatched close parens.