You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
590 lines
24 KiB
590 lines
24 KiB
9 years ago
|
;;; haskell-font-lock.el --- Font locking module for Haskell Mode -*- lexical-binding: t -*-
|
||
|
|
||
|
;; Copyright 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
|
||
|
;; Copyright 1997-1998 Graeme E Moss, and Tommy Thorn
|
||
|
|
||
|
;; Author: 1997-1998 Graeme E Moss <gem@cs.york.ac.uk>
|
||
|
;; 1997-1998 Tommy Thorn <thorn@irisa.fr>
|
||
|
;; 2003 Dave Love <fx@gnu.org>
|
||
|
;; Keywords: faces files Haskell
|
||
|
|
||
|
;; This file is not part of GNU Emacs.
|
||
|
|
||
|
;; This file is free software; you can redistribute it and/or modify
|
||
|
;; it under the terms of the GNU General Public License as published by
|
||
|
;; the Free Software Foundation; either version 3, or (at your option)
|
||
|
;; any later version.
|
||
|
|
||
|
;; This file is distributed in the hope that it will be useful,
|
||
|
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
;; GNU General Public License for more details.
|
||
|
|
||
|
;; You should have received a copy of the GNU General Public License
|
||
|
;; along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
||
|
|
||
|
;;; Code:
|
||
|
|
||
|
(require 'cl-lib)
|
||
|
(require 'haskell-mode)
|
||
|
(require 'font-lock)
|
||
|
|
||
|
;;;###autoload
|
||
|
(defcustom haskell-font-lock-symbols nil
|
||
|
"Display \\ and -> and such using symbols in fonts.
|
||
|
|
||
|
This may sound like a neat trick, but be extra careful: it changes the
|
||
|
alignment and can thus lead to nasty surprises w.r.t layout."
|
||
|
:group 'haskell
|
||
|
:type 'boolean)
|
||
|
|
||
|
;;;###autoload
|
||
|
(defcustom haskell-font-lock-symbols-alist
|
||
|
'(("\\" . "λ")
|
||
|
("not" . "¬")
|
||
|
("->" . "→")
|
||
|
("<-" . "←")
|
||
|
("=>" . "⇒")
|
||
|
("()" . "∅")
|
||
|
("==" . "≡")
|
||
|
("/=" . "≢")
|
||
|
(">=" . "≥")
|
||
|
("<=" . "≤")
|
||
|
("!!" . "‼")
|
||
|
("&&" . "∧")
|
||
|
("||" . "∨")
|
||
|
("sqrt" . "√")
|
||
|
("undefined" . "⊥")
|
||
|
("pi" . "π")
|
||
|
("~>" . "⇝") ;; Omega language
|
||
|
;; ("~>" "↝") ;; less desirable
|
||
|
("-<" . "↢") ;; Paterson's arrow syntax
|
||
|
;; ("-<" "⤙") ;; nicer but uncommon
|
||
|
("::" . "∷")
|
||
|
("." "∘" ; "○"
|
||
|
;; Need a predicate here to distinguish the . used by
|
||
|
;; forall <foo> . <bar>.
|
||
|
haskell-font-lock-dot-is-not-composition)
|
||
|
("forall" . "∀"))
|
||
|
"Alist mapping Haskell symbols to chars.
|
||
|
|
||
|
Each element has the form (STRING . COMPONENTS) or (STRING
|
||
|
COMPONENTS PREDICATE).
|
||
|
|
||
|
STRING is the Haskell symbol.
|
||
|
COMPONENTS is a representation specification suitable as an argument to
|
||
|
`compose-region'.
|
||
|
PREDICATE if present is a function of one argument (the start position
|
||
|
of the symbol) which should return non-nil if this mapping should
|
||
|
be disabled at that position."
|
||
|
:type '(alist string string)
|
||
|
:group 'haskell)
|
||
|
|
||
|
(defun haskell-font-lock-dot-is-not-composition (start)
|
||
|
"Return non-nil if the \".\" at START is not a composition operator.
|
||
|
This is the case if the \".\" is part of a \"forall <tvar> . <type>\"."
|
||
|
(save-excursion
|
||
|
(goto-char start)
|
||
|
(or (re-search-backward "\\<forall\\>[^.\"]*\\="
|
||
|
(line-beginning-position) t)
|
||
|
(not (or
|
||
|
(string= " " (string (char-after start)))
|
||
|
(string= " " (string (char-before start))))))))
|
||
|
|
||
|
;;;###autoload
|
||
|
(defface haskell-keyword-face
|
||
|
'((t :inherit font-lock-keyword-face))
|
||
|
"Face used to highlight Haskell keywords."
|
||
|
:group 'haskell)
|
||
|
|
||
|
;;;###autoload
|
||
|
(defface haskell-constructor-face
|
||
|
'((t :inherit font-lock-type-face))
|
||
|
"Face used to highlight Haskell constructors."
|
||
|
:group 'haskell)
|
||
|
|
||
|
;; This used to be `font-lock-variable-name-face' but it doesn't result in
|
||
|
;; a highlighting that's consistent with other modes (it's mostly used
|
||
|
;; for function defintions).
|
||
|
(defface haskell-definition-face
|
||
|
'((t :inherit font-lock-function-name-face))
|
||
|
"Face used to highlight Haskell definitions."
|
||
|
:group 'haskell)
|
||
|
|
||
|
;; This is probably just wrong, but it used to use
|
||
|
;; `font-lock-function-name-face' with a result that was not consistent with
|
||
|
;; other major modes, so I just exchanged with `haskell-definition-face'.
|
||
|
;;;###autoload
|
||
|
(defface haskell-operator-face
|
||
|
'((t :inherit font-lock-variable-name-face))
|
||
|
"Face used to highlight Haskell operators."
|
||
|
:group 'haskell)
|
||
|
|
||
|
;;;###autoload
|
||
|
(defface haskell-pragma-face
|
||
|
'((t :inherit font-lock-preprocessor-face))
|
||
|
"Face used to highlight Haskell pragmas."
|
||
|
:group 'haskell)
|
||
|
|
||
|
;;;###autoload
|
||
|
(defface haskell-literate-comment-face
|
||
|
'((t :inherit font-lock-doc-face))
|
||
|
"Face with which to fontify literate comments.
|
||
|
Inherit from `default' to avoid fontification of them."
|
||
|
:group 'haskell)
|
||
|
|
||
|
(defun haskell-font-lock-compose-symbol (alist)
|
||
|
"Compose a sequence of ascii chars into a symbol.
|
||
|
Regexp match data 0 points to the chars."
|
||
|
;; Check that the chars should really be composed into a symbol.
|
||
|
(let* ((start (match-beginning 0))
|
||
|
(end (match-end 0))
|
||
|
(syntaxes (cond
|
||
|
((eq (char-syntax (char-after start)) ?w) '(?w))
|
||
|
((eq (char-syntax (char-after start)) ?.) '(?.))
|
||
|
;; Special case for the . used for qualified names.
|
||
|
((and (eq (char-after start) ?\.) (= end (1+ start)))
|
||
|
'(?_ ?\\ ?w))
|
||
|
(t '(?_ ?\\))))
|
||
|
sym-data)
|
||
|
(if (or (memq (char-syntax (or (char-before start) ?\ )) syntaxes)
|
||
|
(memq (char-syntax (or (char-after end) ?\ )) syntaxes)
|
||
|
(or (elt (syntax-ppss) 3) (elt (syntax-ppss) 4))
|
||
|
(and (consp (setq sym-data (cdr (assoc (match-string 0) alist))))
|
||
|
(let ((pred (cadr sym-data)))
|
||
|
(setq sym-data (car sym-data))
|
||
|
(funcall pred start))))
|
||
|
;; No composition for you. Let's actually remove any composition
|
||
|
;; we may have added earlier and which is now incorrect.
|
||
|
(remove-text-properties start end '(composition))
|
||
|
;; That's a symbol alright, so add the composition.
|
||
|
(compose-region start end sym-data)))
|
||
|
;; Return nil because we're not adding any face property.
|
||
|
nil)
|
||
|
|
||
|
(defun haskell-font-lock-symbols-keywords ()
|
||
|
(when (and haskell-font-lock-symbols
|
||
|
haskell-font-lock-symbols-alist
|
||
|
(fboundp 'compose-region))
|
||
|
`((,(regexp-opt (mapcar 'car haskell-font-lock-symbols-alist) t)
|
||
|
(0 (haskell-font-lock-compose-symbol ',haskell-font-lock-symbols-alist)
|
||
|
;; In Emacs-21, if the `override' field is nil, the face
|
||
|
;; expressions is only evaluated if the text has currently
|
||
|
;; no face. So force evaluation by using `keep'.
|
||
|
keep)))))
|
||
|
|
||
|
;; The font lock regular expressions.
|
||
|
(defun haskell-font-lock-keywords-create (literate)
|
||
|
"Create fontification definitions for Haskell scripts.
|
||
|
Returns keywords suitable for `font-lock-keywords'."
|
||
|
(let* (;; Bird-style literate scripts start a line of code with
|
||
|
;; "^>", otherwise a line of code starts with "^".
|
||
|
(line-prefix (if (eq literate 'bird) "^> ?" "^"))
|
||
|
|
||
|
(varid "\\b[[:lower:]_][[:alnum:]'_]*\\b")
|
||
|
;; We allow ' preceding conids because of DataKinds/PolyKinds
|
||
|
(conid "\\b'?[[:upper:]][[:alnum:]'_]*\\b")
|
||
|
(modid (concat "\\b" conid "\\(\\." conid "\\)*\\b"))
|
||
|
(qvarid (concat modid "\\." varid))
|
||
|
(qconid (concat modid "\\." conid))
|
||
|
(sym "\\s.+")
|
||
|
|
||
|
;; Reserved identifiers
|
||
|
(reservedid
|
||
|
(concat "\\<"
|
||
|
;; `as', `hiding', and `qualified' are part of the import
|
||
|
;; spec syntax, but they are not reserved.
|
||
|
;; `_' can go in here since it has temporary word syntax.
|
||
|
;; (regexp-opt
|
||
|
;; '("case" "class" "data" "default" "deriving" "do"
|
||
|
;; "else" "if" "import" "in" "infix" "infixl"
|
||
|
;; "infixr" "instance" "let" "module" "newtype" "of"
|
||
|
;; "then" "type" "where" "_") t)
|
||
|
"\\(_\\|c\\(ase\\|lass\\)\\|d\\(ata\\|e\\(fault\\|riving\\)\\|o\\)\\|else\\|i\\(mport\\|n\\(fix[lr]?\\|stance\\)\\|[fn]\\)\\|let\\|module\\|mdo\\|newtype\\|of\\|rec\\|proc\\|t\\(hen\\|ype\\)\\|where\\)"
|
||
|
"\\>"))
|
||
|
|
||
|
;; Top-level declarations
|
||
|
(topdecl-var
|
||
|
(concat line-prefix "\\(" varid "\\(?:\\s-*,\\s-*" varid "\\)*" "\\)\\s-*"
|
||
|
;; optionally allow for a single newline after identifier
|
||
|
;; NOTE: not supported for bird-style .lhs files
|
||
|
(if (eq literate 'bird) nil "\\([\n]\\s-+\\)?")
|
||
|
;; A toplevel declaration can be followed by a definition
|
||
|
;; (=), a type (::) or (∷), a guard, or a pattern which can
|
||
|
;; either be a variable, a constructor, a parenthesized
|
||
|
;; thingy, or an integer or a string.
|
||
|
"\\(" varid "\\|" conid "\\|::\\|∷\\|=\\||\\|\\s(\\|[0-9\"']\\)"))
|
||
|
(topdecl-var2
|
||
|
(concat line-prefix "\\(" varid "\\|" conid "\\)\\s-*`\\(" varid "\\)`"))
|
||
|
(topdecl-bangpat
|
||
|
(concat line-prefix "\\(" varid "\\)\\s-*!"))
|
||
|
(topdecl-sym
|
||
|
(concat line-prefix "\\(" varid "\\|" conid "\\)\\s-*\\(" sym "\\)"))
|
||
|
(topdecl-sym2 (concat line-prefix "(\\(" sym "\\))"))
|
||
|
|
||
|
keywords)
|
||
|
|
||
|
(setq keywords
|
||
|
`(;; NOTICE the ordering below is significant
|
||
|
;;
|
||
|
("^#.*$" 0 'font-lock-preprocessor-face t)
|
||
|
|
||
|
,@(haskell-font-lock-symbols-keywords)
|
||
|
|
||
|
(,reservedid 1 'haskell-keyword-face)
|
||
|
|
||
|
;; Special case for `as', `hiding', `safe' and `qualified', which are
|
||
|
;; keywords in import statements but are not otherwise reserved.
|
||
|
("\\<import[ \t]+\\(?:\\(safe\\>\\)[ \t]*\\)?\\(?:\\(qualified\\>\\)[ \t]*\\)?\\(?:\"[^\"]*\"[\t ]*\\)?[^ \t\n()]+[ \t]*\\(?:\\(\\<as\\>\\)[ \t]*[^ \t\n()]+[ \t]*\\)?\\(\\<hiding\\>\\)?"
|
||
|
(1 'haskell-keyword-face nil lax)
|
||
|
(2 'haskell-keyword-face nil lax)
|
||
|
(3 'haskell-keyword-face nil lax)
|
||
|
(4 'haskell-keyword-face nil lax))
|
||
|
|
||
|
;; Special case for `foreign import'
|
||
|
;; keywords in foreign import statements but are not otherwise reserved.
|
||
|
("\\<\\(foreign\\)[ \t]+\\(import\\)[ \t]+\\(?:\\(ccall\\|stdcall\\|cplusplus\\|jvm\\|dotnet\\)[ \t]+\\)?\\(?:\\(safe\\|unsafe\\|interruptible\\)[ \t]+\\)?"
|
||
|
(1 'haskell-keyword-face nil lax)
|
||
|
(2 'haskell-keyword-face nil lax)
|
||
|
(3 'haskell-keyword-face nil lax)
|
||
|
(4 'haskell-keyword-face nil lax))
|
||
|
|
||
|
;; Special case for `foreign export'
|
||
|
;; keywords in foreign export statements but are not otherwise reserved.
|
||
|
("\\<\\(foreign\\)[ \t]+\\(export\\)[ \t]+\\(?:\\(ccall\\|stdcall\\|cplusplus\\|jvm\\|dotnet\\)[ \t]+\\)?"
|
||
|
(1 'haskell-keyword-face nil lax)
|
||
|
(2 'haskell-keyword-face nil lax)
|
||
|
(3 'haskell-keyword-face nil lax))
|
||
|
|
||
|
;; Toplevel Declarations.
|
||
|
;; Place them *before* generic id-and-op highlighting.
|
||
|
(,topdecl-var (1 'haskell-definition-face))
|
||
|
(,topdecl-var2 (2 'haskell-definition-face))
|
||
|
(,topdecl-bangpat (1 'haskell-definition-face))
|
||
|
(,topdecl-sym (2 (unless (member (match-string 2) '("\\" "=" "->" "→" "<-" "←" "::" "∷" "," ";" "`"))
|
||
|
'haskell-definition-face)))
|
||
|
(,topdecl-sym2 (1 (unless (member (match-string 1) '("\\" "=" "->" "→" "<-" "←" "::" "∷" "," ";" "`"))
|
||
|
'haskell-definition-face)))
|
||
|
|
||
|
;; These four are debatable...
|
||
|
("(\\(,*\\|->\\))" 0 'haskell-constructor-face)
|
||
|
("\\[\\]" 0 'haskell-constructor-face)
|
||
|
|
||
|
(,(concat "`" varid "`") 0 'haskell-operator-face)
|
||
|
(,(concat "`" conid "`") 0 'haskell-operator-face)
|
||
|
(,(concat "`" qvarid "`") 0 'haskell-operator-face)
|
||
|
(,(concat "`" qconid "`") 0 'haskell-operator-face)
|
||
|
|
||
|
(,qconid 0 'haskell-constructor-face)
|
||
|
|
||
|
(,conid 0 'haskell-constructor-face)
|
||
|
|
||
|
(,sym 0 (if (and (eq (char-after (match-beginning 0)) ?:)
|
||
|
(not (member (match-string 0) '("::" "∷"))))
|
||
|
'haskell-constructor-face
|
||
|
'haskell-operator-face))))
|
||
|
keywords))
|
||
|
|
||
|
(defvar haskell-font-lock-latex-cache-pos nil
|
||
|
"Position of cache point used by `haskell-font-lock-latex-cache-in-comment'.
|
||
|
Should be at the start of a line.")
|
||
|
(make-variable-buffer-local 'haskell-font-lock-latex-cache-pos)
|
||
|
|
||
|
(defvar haskell-font-lock-latex-cache-in-comment nil
|
||
|
"If `haskell-font-lock-latex-cache-pos' is outside a
|
||
|
\\begin{code}..\\end{code} block (and therefore inside a comment),
|
||
|
this variable is set to t, otherwise nil.")
|
||
|
(make-variable-buffer-local 'haskell-font-lock-latex-cache-in-comment)
|
||
|
|
||
|
(defun haskell-font-lock-latex-comments (end)
|
||
|
"Sets `match-data' according to the region of the buffer before end
|
||
|
that should be commented under LaTeX-style literate scripts."
|
||
|
(let ((start (point)))
|
||
|
(if (= start end)
|
||
|
;; We're at the end. No more to fontify.
|
||
|
nil
|
||
|
(if (not (eq start haskell-font-lock-latex-cache-pos))
|
||
|
;; If the start position is not cached, calculate the state
|
||
|
;; of the start.
|
||
|
(progn
|
||
|
(setq haskell-font-lock-latex-cache-pos start)
|
||
|
;; If the previous \begin{code} or \end{code} is a
|
||
|
;; \begin{code}, then start is not in a comment, otherwise
|
||
|
;; it is in a comment.
|
||
|
(setq haskell-font-lock-latex-cache-in-comment
|
||
|
(if (and
|
||
|
(re-search-backward
|
||
|
"^\\(\\(\\\\begin{code}\\)\\|\\(\\\\end{code}\\)\\)$"
|
||
|
(point-min) t)
|
||
|
(match-end 2))
|
||
|
nil t))
|
||
|
;; Restore position.
|
||
|
(goto-char start)))
|
||
|
(if haskell-font-lock-latex-cache-in-comment
|
||
|
(progn
|
||
|
;; If start is inside a comment, search for next \begin{code}.
|
||
|
(re-search-forward "^\\\\begin{code}$" end 'move)
|
||
|
;; Mark start to end of \begin{code} (if present, till end
|
||
|
;; otherwise), as a comment.
|
||
|
(set-match-data (list start (point)))
|
||
|
;; Return point, as a normal regexp would.
|
||
|
(point))
|
||
|
;; If start is inside a code block, search for next \end{code}.
|
||
|
(if (re-search-forward "^\\\\end{code}$" end t)
|
||
|
;; If one found, mark it as a comment, otherwise finish.
|
||
|
(point))))))
|
||
|
|
||
|
(defconst haskell-basic-syntactic-keywords
|
||
|
'(;; Character constants (since apostrophe can't have string syntax).
|
||
|
;; Beware: do not match something like 's-}' or '\n"+' since the first '
|
||
|
;; might be inside a comment or a string.
|
||
|
;; This still gets fooled with "'"'"'"'"'"', but ... oh well.
|
||
|
("\\Sw\\('\\)\\([^\\'\n]\\|\\\\.[^\\'\n \"}]*\\)\\('\\)" (1 "\"") (3 "\""))
|
||
|
;; Deal with instances of `--' which don't form a comment
|
||
|
("[!#$%&*+./:<=>?@^|~\\]*--[!#$%&*+./:<=>?@^|~\\-]*" (0 (cond ((or (nth 3 (syntax-ppss)) (numberp (nth 4 (syntax-ppss))))
|
||
|
;; There are no such instances inside
|
||
|
;; nestable comments or strings
|
||
|
nil)
|
||
|
((string-match "\\`-*\\'" (match-string 0))
|
||
|
;; Sequence of hyphens. Do nothing in
|
||
|
;; case of things like `{---'.
|
||
|
nil)
|
||
|
((string-match "\\`[^-]+--.*" (match-string 0))
|
||
|
;; Extra characters before comment starts
|
||
|
".")
|
||
|
(t ".")))) ; other symbol sequence
|
||
|
|
||
|
;; Implement Haskell Report 'escape' and 'gap' rules. Backslash
|
||
|
;; inside of a string is escaping unless it is preceeded by
|
||
|
;; another escaping backslash. There can be whitespace between
|
||
|
;; those two.
|
||
|
;;
|
||
|
;; Backslashes outside of string never escape.
|
||
|
;;
|
||
|
;; Note that (> 0 (skip-syntax-backward ".")) this skips over *escaping*
|
||
|
;; backslashes only.
|
||
|
("\\\\" (0 (when (save-excursion (and (nth 3 (syntax-ppss))
|
||
|
(goto-char (match-beginning 0))
|
||
|
(skip-syntax-backward "->")
|
||
|
(or (not (eq ?\\ (char-before)))
|
||
|
(> 0 (skip-syntax-backward ".")))))
|
||
|
"\\")))
|
||
|
|
||
|
;; QuasiQuotes syntax: [quoter| string |], quoter is unqualified
|
||
|
;; name, no spaces, string is arbitrary (including newlines),
|
||
|
;; finishes at the first occurence of |], no escaping is provided.
|
||
|
;;
|
||
|
;; The quoter cannot be "e", "t", "d", or "p", since those overlap
|
||
|
;; with Template Haskell quotations.
|
||
|
;;
|
||
|
;; QuasiQuotes opens only when outside of a string or a comment
|
||
|
;; and closes only when inside a quasiquote.
|
||
|
;;
|
||
|
;; (syntax-ppss) returns list with two interesting elements:
|
||
|
;; nth 3. non-nil if inside a string. (it is the character that will
|
||
|
;; terminate the string, or t if the string should be terminated
|
||
|
;; by a generic string delimiter.)
|
||
|
;; nth 4. nil if outside a comment, t if inside a non-nestable comment,
|
||
|
;; else an integer (the current comment nesting).
|
||
|
;;
|
||
|
;; Note also that we need to do in in a single pass, hence a regex
|
||
|
;; that covers both the opening and the ending of a quasiquote.
|
||
|
|
||
|
("\\(\\[[[:alnum:]]+\\)?\\(|\\)\\(]\\)?"
|
||
|
(2 (save-excursion
|
||
|
(goto-char (match-beginning 0))
|
||
|
(if (eq ?\[ (char-after))
|
||
|
;; opening case
|
||
|
(unless (or (nth 3 (syntax-ppss))
|
||
|
(nth 4 (syntax-ppss))
|
||
|
(member (match-string 1)
|
||
|
'("[e" "[t" "[d" "[p")))
|
||
|
"\"")
|
||
|
;; closing case
|
||
|
(when (and (eq ?| (nth 3 (syntax-ppss)))
|
||
|
(equal "]" (match-string 3))
|
||
|
)
|
||
|
"\"")))))
|
||
|
))
|
||
|
|
||
|
(defconst haskell-bird-syntactic-keywords
|
||
|
(cons '("^[^\n>]" (0 "<"))
|
||
|
haskell-basic-syntactic-keywords))
|
||
|
|
||
|
(defconst haskell-latex-syntactic-keywords
|
||
|
(append
|
||
|
'(("^\\\\begin{code}\\(\n\\)" 1 "!")
|
||
|
;; Note: buffer is widened during font-locking.
|
||
|
("\\`\\(.\\|\n\\)" (1 "!")) ; start comment at buffer start
|
||
|
("^\\(\\\\\\)end{code}$" 1 "!"))
|
||
|
haskell-basic-syntactic-keywords))
|
||
|
|
||
|
(defun haskell-syntactic-face-function (state)
|
||
|
"`font-lock-syntactic-face-function' for Haskell."
|
||
|
(cond
|
||
|
((nth 3 state) 'font-lock-string-face) ; as normal
|
||
|
;; Else comment. If it's from syntax table, use default face.
|
||
|
((or (eq 'syntax-table (nth 7 state))
|
||
|
(and (eq haskell-literate 'bird)
|
||
|
(memq (char-before (nth 8 state)) '(nil ?\n))))
|
||
|
'haskell-literate-comment-face)
|
||
|
;; Detect pragmas. A pragma is enclosed in special comment
|
||
|
;; delimeters {-# .. #-}.
|
||
|
((save-excursion
|
||
|
(goto-char (nth 8 state))
|
||
|
(and (looking-at "{-#")
|
||
|
(forward-comment 1)
|
||
|
(goto-char (- (point) 3))
|
||
|
(looking-at "#-}")))
|
||
|
'haskell-pragma-face)
|
||
|
;; Haddock comment start with either "-- [|^*$]" or "{- ?[|^*$]"
|
||
|
;; (note space optional for nested comments and mandatory for
|
||
|
;; double dash comments).
|
||
|
;;
|
||
|
;; Haddock comment will also continue on next line, provided:
|
||
|
;; - current line is a double dash haddock comment
|
||
|
;; - next line is also double dash comment
|
||
|
;; - there is only whitespace between
|
||
|
;;
|
||
|
;; We recognize double dash haddock comments by property
|
||
|
;; 'font-lock-doc-face attached to newline. In case of bounded
|
||
|
;; comments newline is outside of comment.
|
||
|
((save-excursion
|
||
|
(goto-char (nth 8 state))
|
||
|
(or (looking-at "\\(?:{- ?\\|-- \\)[|^*$]")
|
||
|
(and (looking-at "--") ; are we at double dash comment
|
||
|
(forward-line -1) ; this is nil on first line
|
||
|
(eq (get-text-property (line-end-position) 'face)
|
||
|
'font-lock-doc-face) ; is a doc face
|
||
|
(forward-line)
|
||
|
(skip-syntax-forward "-") ; see if there is only whitespace
|
||
|
(eq (point) (nth 8 state))))) ; we are back in position
|
||
|
'font-lock-doc-face)
|
||
|
(t 'font-lock-comment-face)))
|
||
|
|
||
|
(defconst haskell-font-lock-keywords
|
||
|
(haskell-font-lock-keywords-create nil)
|
||
|
"Font lock definitions for non-literate Haskell.")
|
||
|
|
||
|
(defconst haskell-font-lock-bird-literate-keywords
|
||
|
(haskell-font-lock-keywords-create 'bird)
|
||
|
"Font lock definitions for Bird-style literate Haskell.")
|
||
|
|
||
|
(defconst haskell-font-lock-latex-literate-keywords
|
||
|
(haskell-font-lock-keywords-create 'latex)
|
||
|
"Font lock definitions for LaTeX-style literate Haskell.")
|
||
|
|
||
|
;;;###autoload
|
||
|
(defun haskell-font-lock-choose-keywords ()
|
||
|
(let ((literate (if (boundp 'haskell-literate) haskell-literate)))
|
||
|
(cl-case literate
|
||
|
(bird haskell-font-lock-bird-literate-keywords)
|
||
|
((latex tex) haskell-font-lock-latex-literate-keywords)
|
||
|
(t haskell-font-lock-keywords))))
|
||
|
|
||
|
(defun haskell-font-lock-choose-syntactic-keywords ()
|
||
|
(let ((literate (if (boundp 'haskell-literate) haskell-literate)))
|
||
|
(cl-case literate
|
||
|
(bird haskell-bird-syntactic-keywords)
|
||
|
((latex tex) haskell-latex-syntactic-keywords)
|
||
|
(t haskell-basic-syntactic-keywords))))
|
||
|
|
||
|
(defun haskell-font-lock-defaults-create ()
|
||
|
"Locally set `font-lock-defaults' for Haskell."
|
||
|
(set (make-local-variable 'font-lock-defaults)
|
||
|
'(haskell-font-lock-choose-keywords
|
||
|
nil nil ((?\' . "w") (?_ . "w")) nil
|
||
|
(font-lock-syntactic-keywords
|
||
|
. haskell-font-lock-choose-syntactic-keywords)
|
||
|
(font-lock-syntactic-face-function
|
||
|
. haskell-syntactic-face-function)
|
||
|
;; Get help from font-lock-syntactic-keywords.
|
||
|
(parse-sexp-lookup-properties . t))))
|
||
|
|
||
|
;; The main functions.
|
||
|
(defun turn-on-haskell-font-lock ()
|
||
|
"Turns on font locking in current buffer for Haskell 1.4 scripts.
|
||
|
|
||
|
Changes the current buffer's `font-lock-defaults', and adds the
|
||
|
following variables:
|
||
|
|
||
|
`haskell-keyword-face' for reserved keywords and syntax,
|
||
|
`haskell-constructor-face' for data- and type-constructors, class names,
|
||
|
and module names,
|
||
|
`haskell-operator-face' for symbolic and alphanumeric operators,
|
||
|
`haskell-default-face' for ordinary code.
|
||
|
|
||
|
The variables are initialised to the following font lock default faces:
|
||
|
|
||
|
`haskell-keyword-face' `font-lock-keyword-face'
|
||
|
`haskell-constructor-face' `font-lock-type-face'
|
||
|
`haskell-operator-face' `font-lock-function-name-face'
|
||
|
`haskell-default-face' <default face>
|
||
|
|
||
|
Two levels of fontification are defined: level one (the default)
|
||
|
and level two (more colour). The former does not colour operators.
|
||
|
Use the variable `font-lock-maximum-decoration' to choose
|
||
|
non-default levels of fontification. For example, adding this to
|
||
|
.emacs:
|
||
|
|
||
|
(setq font-lock-maximum-decoration '((haskell-mode . 2) (t . 0)))
|
||
|
|
||
|
uses level two fontification for `haskell-mode' and default level for
|
||
|
all other modes. See documentation on this variable for further
|
||
|
details.
|
||
|
|
||
|
To alter an attribute of a face, add a hook. For example, to change
|
||
|
the foreground colour of comments to brown, add the following line to
|
||
|
.emacs:
|
||
|
|
||
|
(add-hook 'haskell-font-lock-hook
|
||
|
(lambda ()
|
||
|
(set-face-foreground 'haskell-comment-face \"brown\")))
|
||
|
|
||
|
Note that the colours available vary from system to system. To see
|
||
|
what colours are available on your system, call
|
||
|
`list-colors-display' from emacs.
|
||
|
|
||
|
To turn font locking on for all Haskell buffers, add this to .emacs:
|
||
|
|
||
|
(add-hook 'haskell-mode-hook 'turn-on-haskell-font-lock)
|
||
|
|
||
|
To turn font locking on for the current buffer, call
|
||
|
`turn-on-haskell-font-lock'. To turn font locking off in the current
|
||
|
buffer, call `turn-off-haskell-font-lock'.
|
||
|
|
||
|
Bird-style literate Haskell scripts are supported: If the value of
|
||
|
`haskell-literate-bird-style' (automatically set by the Haskell mode
|
||
|
of Moss&Thorn) is non-nil, a Bird-style literate script is assumed.
|
||
|
|
||
|
Invokes `haskell-font-lock-hook' if not nil."
|
||
|
(haskell-font-lock-defaults-create)
|
||
|
(run-hooks 'haskell-font-lock-hook)
|
||
|
(turn-on-font-lock))
|
||
|
|
||
|
(defun turn-off-haskell-font-lock ()
|
||
|
"Turns off font locking in current buffer."
|
||
|
(font-lock-mode -1))
|
||
|
|
||
|
(defun haskell-fontify-as-mode (text mode)
|
||
|
"Fontify TEXT as MODE, returning the fontified text."
|
||
|
(with-temp-buffer
|
||
|
(funcall mode)
|
||
|
(insert text)
|
||
|
(if (fboundp 'font-lock-ensure)
|
||
|
(font-lock-ensure)
|
||
|
(with-no-warnings (font-lock-fontify-buffer)))
|
||
|
(buffer-substring (point-min) (point-max))))
|
||
|
|
||
|
;; Provide ourselves:
|
||
|
|
||
|
(provide 'haskell-font-lock)
|
||
|
|
||
|
;; Local Variables:
|
||
|
;; coding: utf-8-unix
|
||
|
;; tab-width: 8
|
||
|
;; End:
|
||
|
|
||
|
;;; haskell-font-lock.el ends here
|