Fix `haskell-interactive-types-for-show-ambiguous'

[drvink]

The regex in haskell-interactive-mode-trigger-compile-error wouldn't match e.g. <interactive>:6:1-2:, preventing the rest of the function from running.

[gracjan]

Thanks.

As far as I know the Warning: part may end up on next line. Do these regexps work correctly in this situation?

[drvink]

I couldn't find an immediate reference for the format of GHC's diagnostic messages, so I looked at what Flycheck had. Looks like ours should be OK, though I haven't tested it.

;; our warning intro regex
"^\n<interactive>:[-0-9]+:[-0-9]+:[\n ]+Warning:"
;; Flycheck's regex for a complete warning
(let ((re (cons "blah"
                '(line-start (file-name) ":" line ":" column ":"
                  (or " " "\n    ") "Warning:" (optional "\n")
                  (message
                   (one-or-more " ") (one-or-more not-newline)
                   (zero-or-more "\n"
                                 (one-or-more " ")
                                 (one-or-more not-newline)))
                  line-end))))
  (flycheck-rx-to-string `(and ,@(cdr re))))
"\\(?:^\\(?1:.+?\\):\\(?2:[[:digit:]]+\\):\\(?3:[[:digit:]]+\\):\\(?:\\(?:\\(?:\n   \\)? \\)\\)Warning:\n?\\(?4: +.+\\(?:\n +.+\\)*\\)$\\)"

;; our error intro regex
"^\n<interactive>:[-0-9]+:[-0-9]+:"
;; Flycheck's
(let ((re (cons "blah"
                '(line-start (file-name) ":" line ":" column ":"
                  (or (message (one-or-more not-newline))
                      (and "\n"
                           (message
                            (one-or-more " ") (one-or-more not-newline)
                            (zero-or-more "\n"
                                          (one-or-more " ")
                                          (one-or-more not-newline)))))
                  line-end))))
  (flycheck-rx-to-string `(and ,@(cdr re))))
"\\(?:^\\(?1:.+?\\):\\(?2:[[:digit:]]+\\):\\(?3:[[:digit:]]+\\):\\(?:\\(?4:.+\\)\\|\n\\(?4: +.+\\(?:\n +.+\\)*\\)\\)$\\)"

[gracjan]

Can you create some unit test ERT cases with some example input? I would hate if it broke by accident.