suite.rc syntax lexers: improve emacs support

etc/syntax/cylc-mode.el

@@ -1,47 +1,118 @@
-;; Simple syntax highlighting for cylc suite definition files.
-;; Author: Luis Kornblueh, 2012
+;; ____________________________________________________________________________
 ;;
-;; 1. copy this file to $HOME/.emacs.d/lisp
-;; 2. add in $HOME/.emacs the following lines:
+;; = cylc-mode.el =
+;;    Emacs syntax highlighting mode for Cylc suite definition (suite.rc) files
+;; ____________________________________________________________________________
 ;;
-;;   (add-to-list 'load-path "~/.emacs.d/lisp/")
-;;   (require 'cylc-mode)
-;;   (setq auto-mode-alist (append auto-mode-alist 
-;;			      (list '("\\.rc$" . cylc-mode))))
-;;   (global-font-lock-mode t)
-;;______________________________________________________________________________
-
-(defconst cylc-mode-version "0.1")
-
-(setq cylc-font-lock-keywords
-      '(("{%[[:alnum:], _=\\(\\)]*%}" . font-lock-constant-face) 
-        ("{#[^\}]+#}" . font-lock-comment-face)
-        ("#.*" . font-lock-comment-face)
-	("{{[[:alnum:] ]*}}" . font-lock-constant-face) 
-        ("\\[\\[\\[[[:alnum:], _]+\\]\\]\\]" . font-lock-type-face)
-        ("\\[\\[\\[[[:alnum:], _]+" . font-lock-type-face)
-        ("\\]\\]\\]" . font-lock-type-face)
-	("\\[\\[[[:alnum:], _]*\\]\\]" . font-lock-function-name-face)
-	("\\[\\[[[:alnum:], _]*" . font-lock-function-name-face)
-	("\\]\\]" . font-lock-function-name-face)
-	("\\[[[:alnum:], ]+\\]" . font-lock-warning-face)
-        ("^[[:alnum:] -_]*=" . font-lock-variable-name-face)
-	))
-
-;; define the mode
+;; = Instructions =
+;;    Place this file in a directory on your emacs load path (or symlink it)
+;;    e.g.
+;;         mkdir -p $HOME/.emacs.d/lisp
+;;         ln -s $CYLC_HOME/etc/cylc-mode.el ~/.emacs.d/lisp/
+;;
+;;    and in your $HOME/.emacs file add the following lines:
+;;
+;;         (add-to-list 'load-path "~/.emacs.d/lisp/")
+;;         (require 'cylc-mode)
+;;
+;; ____________________________________________________________________________
+
+(defvar cylc-mode-hook nil)
+
+;; Extend region hook to ensure correct re-fontifying of the multi-line region
+(defun cylc-font-lock-extend-region ()
+  "Extend the search region to include an entire block of text."
+  ;; Avoid compiler warnings about these global variables from font-lock.el.
+  ;; See the documentation for variable `font-lock-extend-region-functions'.
+  (eval-when-compile (defvar font-lock-beg) (defvar font-lock-end))
+  (save-excursion
+    (goto-char font-lock-beg)
+    (let ((found (or (re-search-backward "\n\n" nil t) (point-min))))
+      (goto-char font-lock-end)
+      (when (re-search-forward "\n\n" nil t)
+        (beginning-of-line)
+        (setq font-lock-end (point)))
+      (setq font-lock-beg found))))
+
+;; Define the mode and the syntax highlighting for it
 (define-derived-mode cylc-mode fundamental-mode
-  "cylc mode"
-  "Major mode for editing CYLC .cylc files"
+  "suite.rc" "Major mode for editing Cylc suite definition files"
 
-  ;; code for syntax highlighting
-  (setq font-lock-defaults '(cylc-font-lock-keywords))
+  ;; Note: ordered according to reverse application precendence, where
+  ;; specification order for faces changes resultant highlighting
 
-)
+  ;; Assignment and dependency characters, but only outside of Jinja2
+  (font-lock-add-keywords nil '(("=+" . font-lock-preprocessor-face)))
+  (font-lock-add-keywords nil '(("=>" . font-lock-keyword-face)))
 
-(provide 'cylc-mode)
+  ;; Cylc setting keys/names
+  (font-lock-add-keywords nil
+    '(("^\\( *[a-zA-Z0-9\-]+ *\\)=+" 1 font-lock-variable-name-face t)))
+
+  ;; Account for section headings (see below) with internal patterns, e.g. a
+  ;; Jinja2 statement, inside by matching start and end heading groups. Note:
+  ;; must be applied here to get correct 'pure' header & ICD highlighting.
+  (font-lock-add-keywords nil
+    '(("\\[\\( *[ a-zA-Z0-9\-\_,.]*\\)" . font-lock-warning-face)))
+  (font-lock-add-keywords nil
+    '(("\\( *[ a-zA-Z0-9\-\_,.]*\\)\\]" . font-lock-warning-face)))
+  (font-lock-add-keywords nil
+    '(("\\[\\[\\( *[ a-zA-Z0-9\-\_,.]*\\)" . font-lock-function-name-face)))
+  (font-lock-add-keywords nil
+    '(("\\( *[ a-zA-Z0-9\-\_,.]*\\)\\]\\]" . font-lock-function-name-face)))
+  (font-lock-add-keywords nil
+    '(("\\[\\[\\[\\( *[ a-zA-Z0-9\-\_,.]*\\)" . font-lock-type-face)))
+  (font-lock-add-keywords nil
+    '(("\\( *[ a-zA-Z0-9\-\_,.]*\\)\\]\\]\\]" . font-lock-type-face)))
+
+  ;; Inter-cycle dependencies (distinguish from top-level section headings)
+  (font-lock-add-keywords nil '(("\\[.*\\]" . font-lock-string-face)))
+
+  ;; All 'pure' Cylc section (of any level e.g. sub-, sub-sub-) headings:
+  ;; ... Top-level headings, enclosed in single square brackets
+  (font-lock-add-keywords nil '(("^ *\\[.*\\]$" . font-lock-warning-face)))
+  ;; ... Second-level (sub-) section headings, enclosed in double brackets
+  (font-lock-add-keywords nil
+    '(("^ *\\[\\[.*\\]\\]$" . font-lock-function-name-face)))
+  ;; ... Third-level (sub-sub-) section headings, enclosed in triple brackets
+  (font-lock-add-keywords nil
+    '(("^ *\\[\\[\\[.*\\]\\]\\]$" . font-lock-type-face)))
 
-(add-hook 'cylc-mode-hook
-  (lambda ()
-    (font-lock-add-keywords nil
-       '(("\\({%[[:alnum:], _=\\(\\)]*%}\\|{{[[:alnum:] ]*}}\\)" 0
-	  font-lock-constant-face t)))))
+  ;; All comments: standard ('# ... ') and Jinja2 ('{# ... #}')
+  (font-lock-add-keywords nil
+    '(("#.*$" . font-lock-comment-face)))  ;; in-line only, by precendece
+  ;; Stop interference. No regex lookarounds in Emacs Lisp; ugly workaround
+  (font-lock-add-keywords nil
+    '(("^#\\(\\([^{].{2}\\|.[^#]\\).*\\|.{0,1}\\)$"
+      . font-lock-comment-face)))
+  (font-lock-add-keywords nil
+    '(("{#\\(\n?.?\\)*?.*#}" . font-lock-comment-face)))  ;; not in-line
+
+  ;; All Jinja2 excl. comments: '{% ... %}' and '{{ ... }}' incl. multiline
+  (font-lock-add-keywords nil
+    '(("{%\\(\n?.?\\)*?.*%}" . font-lock-constant-face)))
+  (font-lock-add-keywords nil '(("{{.*?}}" . font-lock-constant-face)))
+
+  ;; Highlight triple quotes for a multi-line setting value
+  (font-lock-add-keywords nil '(("\"\"\"" . 'font-lock-builtin-face)))
+
+  ;; Add the extend region hook to deal with the multiline matching above
+  (add-hook 'font-lock-extend-region-functions 'cylc-font-lock-extend-region)
+
+  ;; Make sure jit-lock scans larger multiline regions correctly
+  (set (make-local-variable 'jit-lock-contextually) t)
+
+  ;; Force any other fundamental mode inherit font-locking to be ignored, this
+  ;; previously caused double-quotes to break the multiline highlighting
+  (set (make-local-variable 'font-lock-keywords-only) t)
+
+  ;; We need multiline mode
+  (set (make-local-variable 'font-lock-multiline) t)
+
+  ;; Run the mode hooks to allow a user to execute mode-specific actions
+  (run-hooks 'cylc-mode-hook))
+
+;;;###autoload
+(add-to-list 'auto-mode-alist '("suite*.rc" . cylc-mode))
+
+(provide 'cylc-mode)