877 lines (762 sloc) 31.7 KB
;;; haml-mode.el --- Major mode for editing Haml files
;; Copyright (c) 2007, 2008 Natalie Weizenbaum
;; Author: Natalie Weizenbaum
;; URL:
;; Package-Requires: ((emacs "24") (cl-lib "0.5"))
;; Package-Version: 0
;; Created: 2007-03-08
;; By: Natalie Weizenbaum
;; Keywords: markup, languages, html
;;; Commentary:
;; Because Haml's indentation schema is similar
;; to that of YAML and Python, many indentation-related
;; functions are similar to those in yaml-mode and python-mode.
;; To install, save this on your load path and add the following to
;; your .emacs file:
;; (require 'haml-mode)
;;; Code:
(require 'cl-lib)
(require 'ruby-mode)
;; Additional (optional) libraries for fontification
(require 'css-mode nil t)
(require 'textile-mode nil t)
(require 'markdown-mode nil t)
(require 'js nil t)
;; User definable variables
(defgroup haml nil
"Support for the Haml template language."
:group 'languages
:prefix "haml-")
(defcustom haml-mode-hook nil
"Hook run when entering Haml mode."
:type 'hook
:group 'haml)
(defcustom haml-indent-offset 2
"Amount of offset per level of indentation."
:type 'integer
:group 'haml)
(defcustom haml-backspace-backdents-nesting t
"Non-nil to have `haml-electric-backspace' re-indent blocks of code.
This means that all code nested beneath the backspaced line is
re-indented along with the line itself."
:type 'boolean
:group 'haml)
(defvar haml-indent-function 'haml-indent-p
"A function for checking if nesting is allowed.
This function should look at the current line and return t
if the next line could be nested within this line.
The function can also return a positive integer to indicate
a specific level to which the current line could be indented.")
(defconst haml-tag-beg-re
"^[ \t]*\\([%\\.#][a-z0-9_:\\-]+\\)+\\(?:(.*)\\|{.*}\\|\\[.*\\]\\)*"
"A regexp matching the beginning of a Haml tag, through (), {}, and [].")
(defvar haml-block-openers
`(,(concat haml-tag-beg-re "[><]*[ \t]*$")
"^[ \t]*[&!]?[-=~].*do[ \t]*\\(|.*|[ \t]*\\)?$"
,(concat "^[ \t]*[&!]?[-=~][ \t]*\\("
(regexp-opt '("if" "unless" "while" "until" "else" "for"
"begin" "elsif" "rescue" "ensure" "when"))
"^[ \t]*/\\(\\[.*\\]\\)?[ \t]*$"
"^[ \t]*-#"
"^[ \t]*:")
"A list of regexps that match lines of Haml that open blocks.
That is, a Haml line that can have text nested beneath it should
be matched by a regexp in this list.")
;; Font lock
(defun haml-nested-regexp (re)
"Create a regexp to match a block starting with RE.
The line containing RE is matched, as well as all lines indented beneath it."
(concat "^\\([ \t]*\\)\\(" re "\\)\\([ \t]*\\(?:\n\\(?:\\1 +[^\n]*\\)?\\)*\n?\\)$"))
(defconst haml-font-lock-keywords
`((haml-highlight-interpolation 1 font-lock-variable-name-face prepend)
(haml-highlight-ruby-tag 1 font-lock-preprocessor-face)
(haml-highlight-ruby-script 1 font-lock-preprocessor-face)
;; TODO: distinguish between "/" comments, which can contain HAML
;; output directives, and "-#", which are completely ignored
("^!!!.*" 0 font-lock-constant-face)
("\\s| *$" 0 font-lock-string-face)))
(defconst haml-filter-re (haml-nested-regexp ":[[:alnum:]_\\-]+"))
(defconst haml-comment-re (haml-nested-regexp "\\(?:-\\#\\|/\\)[^\n]*"))
(defun haml-highlight-comment (limit)
"Highlight any -# or / comment found up to LIMIT."
(when (re-search-forward haml-comment-re limit t)
(let ((beg (match-beginning 0))
(end (match-end 0)))
(put-text-property beg end 'face 'font-lock-comment-face)
(goto-char end))))
;; Fontifying sub-regions for other languages
(defun haml-fontify-region
(beg end keywords syntax-table syntax-propertize-fn)
"Fontify a region between BEG and END using another mode's fontification.
SYNTAX-PROPERTIZE-FN are the values of that mode's
`font-lock-keywords', `font-lock-syntax-table',
`font-lock-syntactic-keywords', and `syntax-propertize-function'
(let ((font-lock-keywords keywords)
(font-lock-syntax-table syntax-table)
(syntax-propertize-function syntax-propertize-fn)
(font-lock-multiline 'undecided)
(font-lock-dont-widen t)
(narrow-to-region (1- beg) end)
;; font-lock-fontify-region apparently isn't inclusive,
;; so we have to move the beginning back one char
(font-lock-fontify-region (1- beg) end))))))
(defun haml-fontify-region-as-ruby (beg end)
"Use Ruby's font-lock variables to fontify the region between BEG and END."
(haml-fontify-region beg end ruby-font-lock-keywords
(if (fboundp 'ruby-syntax-propertize)
(defun haml-fontify-region-as-css (beg end)
"Fontify CSS code from BEG to END.
This requires that `css-mode' is available.
`css-mode' is included with Emacs 23."
(when (boundp 'css-font-lock-keywords)
(haml-fontify-region beg end
(defun haml-fontify-region-as-javascript (beg end)
"Fontify javascript code from BEG to END.
This requires that Karl Landström's javascript mode be available, either as the
\"js.el\" bundled with Emacs >= 23, or as \"javascript.el\" found in ELPA and
(when js--font-lock-keywords-3
(when (and (fboundp 'js--update-quick-match-re)
(null js--quick-match-re-func))
(haml-fontify-region beg end
(defun haml-fontify-region-as-textile (beg end)
"Highlight textile from BEG to END.
This requires that `textile-mode' be available.
Note that the results are not perfect, since `textile-mode' expects
certain constructs such as \"h1.\" to be at the beginning of a line,
and indented Haml filters always have leading whitespace."
(if (boundp 'textile-font-lock-keywords)
(haml-fontify-region beg end textile-font-lock-keywords textile-mode-syntax-table nil)))
(defun haml-fontify-region-as-markdown (beg end)
"Highlight markdown from BEG to END.
This requires that `markdown-mode' be available."
(if (boundp 'markdown-mode-font-lock-keywords)
(haml-fontify-region beg end
(defvar haml-fontify-filter-functions-alist
'(("ruby" . haml-fontify-region-as-ruby)
("css" . haml-fontify-region-as-css)
("javascript" . haml-fontify-region-as-javascript)
("textile" . haml-fontify-region-as-textile)
("markdown" . haml-fontify-region-as-markdown))
"An alist of (FILTER-NAME . FUNCTION) used to fontify code regions.
FILTER-NAME is a string and FUNCTION is a function which will be
used to fontify the filter's indented code region. FUNCTION will
be passed the extents of that region in two arguments BEG and
(defun haml-highlight-filter (limit)
"Highlight any :filter region found in the text up to LIMIT."
(when (re-search-forward haml-filter-re limit t)
;; fontify the filter name
(put-text-property (match-beginning 2) (1+ (match-end 2))
'face font-lock-preprocessor-face)
(let ((filter-name (substring (match-string 2) 1))
(code-start (1+ (match-beginning 3)))
(code-end (match-end 3)))
(funcall (or (cdr (assoc filter-name haml-fontify-filter-functions-alist))
#'(lambda (beg end)
(put-text-property beg end
code-start code-end))
(goto-char (match-end 0)))))
(defconst haml-possibly-multiline-code-re
"\\(\\(?:.*?,[ \t]*\n\\)*.*\\)"
"Regexp to match trailing ruby code which may continue onto subsequent lines.")
(defconst haml-ruby-script-re
(concat "^[ \t]*\\(-\\|[&!]?\\(?:=\\|~\\)\\)[^=]" haml-possibly-multiline-code-re)
"Regexp to match -, = or ~ blocks and any continued code lines.")
(defun haml-highlight-ruby-script (limit)
"Highlight a Ruby script expression (-, =, or ~).
LIMIT works as it does in `re-search-forward'."
(when (re-search-forward haml-ruby-script-re limit t)
(haml-fontify-region-as-ruby (match-beginning 2) (match-end 2))))
(defun haml-move (re)
"Try matching and moving to the end of regular expression RE.
Returns non-nil if the expression was sucessfully matched."
(when (looking-at re)
(goto-char (match-end 0))
(defun haml-highlight-ruby-tag (limit)
"Highlight Ruby code within a Haml tag.
LIMIT works as it does in `re-search-forward'.
This highlights the tag attributes and object refs of the tag,
as well as the script expression (-, =, or ~) following the tag.
For example, this will highlight all of the following:
%p{:foo => 'bar'}
%p= 'baz'
%p{:foo => 'bar'}[@bar]= 'baz'"
(when (re-search-forward "^[ \t]*[%.#]" limit t)
(forward-char -1)
;; Highlight tag, classes, and ids
(while (haml-move "\\([.#%]\\)[a-z0-9_:\\-]*")
(put-text-property (match-beginning 0) (match-end 0) 'face
(cl-case (char-after (match-beginning 1))
(?% font-lock-keyword-face)
(?# font-lock-function-name-face)
(?. font-lock-variable-name-face))))
(cl-block loop
(while t
(let ((eol (save-excursion (end-of-line) (point))))
(cl-case (char-after)
;; Highlight obj refs
(forward-char 1)
(let ((beg (point)))
(haml-limited-forward-sexp eol)
(haml-fontify-region-as-ruby beg (point))))
;; Highlight new attr hashes
(forward-char 1)
(and (haml-parse-new-attr-hash
(lambda (type beg end)
(cl-case type
(name (put-text-property beg end
(value (haml-fontify-region-as-ruby beg end)))))
(not (eobp)))
(forward-line 1)
;; Highlight old attr hashes
(let ((beg (point)))
(haml-limited-forward-sexp eol)
;; Check for multiline
(while (and (eolp) (eq (char-before) ?,) (not (eobp)))
(let ((eol (save-excursion (end-of-line) (point))))
;; If no sexps are closed,
;; we're still continuing a multiline hash
(if (>= (car (parse-partial-sexp (point) eol)) 0)
;; If sexps have been closed,
;; set the point at the end of the total sexp
(goto-char beg)
(haml-limited-forward-sexp eol))))
(haml-fontify-region-as-ruby (1+ beg) (point))))
(t (cl-return-from loop))))))
;; Move past end chars
(haml-move "[<>&!]+")
;; Highlight script
(if (looking-at (concat "\\([=~]\\) " haml-possibly-multiline-code-re))
(haml-fontify-region-as-ruby (match-beginning 2) (match-end 2))
;; Give font-lock something to highlight
(forward-char -1)
(looking-at "\\(\\)"))
(defun haml-highlight-interpolation (limit)
"Highlight Ruby interpolation (#{foo}).
LIMIT works as it does in `re-search-forward'."
(when (re-search-forward "\\(#{\\)" limit t)
(forward-char -1)
(let ((beg (point)))
(haml-limited-forward-sexp limit)
(haml-fontify-region-as-ruby (1+ beg) (point)))
(when (eq (char-before) ?\})
(put-text-property (1- (point)) (point)
'face font-lock-variable-name-face))
(defun haml-limited-forward-sexp (limit &optional arg)
"Move forward using `forward-sexp' or to LIMIT, whichever comes first.
With ARG, do it that many times."
(let (forward-sexp-function)
(condition-case err
(narrow-to-region (point) limit)
(forward-sexp arg))
(unless (equal (nth 1 err) "Unbalanced parentheses")
(signal 'scan-error (cdr err)))
(goto-char limit)))))
(defun haml-find-containing-block (re)
"If point is inside a block matching RE, return (start . end) for the block."
(let ((pos (point))
start end)
(when (and
(or (looking-at re)
(when (re-search-backward re nil t)
(looking-at re)))
(< pos (match-end 0)))
(setq start (match-beginning 0)
end (match-end 0)))
(when start
(cons start end)))))
(defun haml-maybe-extend-region (extender)
"Maybe extend the font lock region using EXTENDER.
With point at the beginning of the font lock region, EXTENDER is called.
If it returns a (START . END) pair, those positions are used to possibly
extend the font lock region."
(let ((old-beg font-lock-beg)
(old-end font-lock-end))
(goto-char font-lock-beg)
(let ((new-bounds (funcall extender)))
(when new-bounds
(setq font-lock-beg (min font-lock-beg (car new-bounds))
font-lock-end (max font-lock-end (cdr new-bounds))))))
(or (/= old-beg font-lock-beg)
(/= old-end font-lock-end))))
(defun haml-extend-region-nested-below ()
"Extend the font-lock region to any subsequent indented lines."
(lambda ()
(when (looking-at (haml-nested-regexp "[^ \t].*"))
(cons (match-beginning 0) (match-end 0))))))
(defun haml-extend-region-to-containing-block (re)
"Extend the font-lock region to the smallest containing block matching RE."
(lambda ()
(haml-find-containing-block re))))
(defun haml-extend-region-filter ()
"Extend the font-lock region to an enclosing filter."
(haml-extend-region-to-containing-block haml-filter-re))
(defun haml-extend-region-comment ()
"Extend the font-lock region to an enclosing comment."
(haml-extend-region-to-containing-block haml-comment-re))
(defun haml-extend-region-ruby-script ()
"Extend the font-lock region to encompass any current -/=/~ line."
(haml-extend-region-to-containing-block haml-ruby-script-re))
(defun haml-extend-region-multiline-hashes ()
"Extend the font-lock region to encompass multiline attribute hashes."
(lambda ()
(let ((attr-props (haml-parse-multiline-attr-hash))
(when attr-props
(setq start (cdr (assq 'point attr-props)))
;; Move through multiline attrs
(when (eq (char-before) ?,)
(while (progn (end-of-line)
(and (eq (char-before) ?,) (not (eobp))))
(forward-line -1)
(setq multiline-end (point))))
(goto-char (+ (cdr (assq 'point attr-props))
(cdr (assq 'hash-indent attr-props))
(or multiline-end
(save-excursion (end-of-line) (point))))
(cons start (point)))))))
(defun haml-extend-region-contextual ()
"Extend the font lock region piecemeal.
The result of calling this function repeatedly until it returns
nil is that (FONT-LOCK-BEG . FONT-LOCK-END) will be the smallest
possible region in which font-locking could be affected by
changes in the initial region."
;; Mode setup
(defvar haml-mode-syntax-table
(let ((table (make-syntax-table)))
(modify-syntax-entry ?: "." table)
(modify-syntax-entry ?' "\"" table)
"Syntax table in use in `haml-mode' buffers.")
(defvar haml-mode-map
(let ((map (make-sparse-keymap)))
(define-key map [backspace] 'haml-electric-backspace)
(define-key map "\C-?" 'haml-electric-backspace)
(define-key map "\C-c\C-f" 'haml-forward-sexp)
(define-key map "\C-c\C-b" 'haml-backward-sexp)
(define-key map "\C-c\C-u" 'haml-up-list)
(define-key map "\C-c\C-d" 'haml-down-list)
(define-key map "\C-c\C-k" 'haml-kill-line-and-indent)
(define-key map "\C-c\C-r" 'haml-output-region)
(define-key map "\C-c\C-l" 'haml-output-buffer)
(define-derived-mode haml-mode prog-mode "Haml"
"Major mode for editing Haml files.
(setq font-lock-extend-region-functions '(haml-extend-region-contextual))
(set (make-local-variable 'jit-lock-contextually) t)
(set (make-local-variable 'font-lock-multiline) t)
(set (make-local-variable 'indent-line-function) 'haml-indent-line)
(set (make-local-variable 'indent-region-function) 'haml-indent-region)
(set (make-local-variable 'parse-sexp-lookup-properties) t)
(set (make-local-variable 'comment-start) "-#")
(setq font-lock-defaults '((haml-font-lock-keywords) t t))
(when (boundp 'electric-indent-inhibit)
(setq electric-indent-inhibit t))
(setq indent-tabs-mode nil))
;; Useful functions
(defun haml-comment-block ()
"Comment the current block of Haml code."
(let ((indent (current-indentation)))
(insert "-#")
(indent-to indent)
(haml-reindent-region-by haml-indent-offset))))
(defun haml-uncomment-block ()
"Uncomment the current block of Haml code."
(while (not (looking-at haml-comment-re))
(kill-line 1)
(haml-reindent-region-by (- haml-indent-offset))))
(defun haml-replace-region (start end)
"Replace the current block of Haml code with the HTML equivalent.
Called from a program, START and END specify the region to indent."
(interactive "r")
(goto-char end)
(setq end (point-marker))
(goto-char start)
(let ((ci (current-indentation)))
(while (re-search-forward "^ +" end t)
(replace-match (make-string (- (current-indentation) ci) ? ))))
(shell-command-on-region start end "haml" "haml-output" t)))
(defun haml-output-region (start end)
"Displays the HTML output for the current block of Haml code.
Called from a program, START and END specify the region to indent."
(interactive "r")
(kill-new (buffer-substring start end))
(haml-indent-region (point-min) (point-max))
(shell-command-on-region (point-min) (point-max) "haml" "haml-output")))
(defun haml-output-buffer ()
"Displays the HTML output for entire buffer."
(haml-output-region (point-min) (point-max)))
;; Navigation
(defun haml-forward-through-whitespace (&optional backward)
"Move the point forward through any whitespace.
The point will move forward at least one line, until it reaches
either the end of the buffer or a line with no whitespace.
If BACKWARD is non-nil, move the point backward instead."
(let ((arg (if backward -1 1))
(endp (if backward 'bobp 'eobp)))
(cl-loop do (forward-line arg)
while (and (not (funcall endp))
(looking-at "^[ \t]*$")))))
(defun haml-at-indent-p ()
"Return non-nil if the point is before any text on the line."
(let ((opoint (point)))
(>= (point) opoint))))
(defun haml-forward-sexp (&optional arg)
"Move forward across one nested expression.
With ARG, do it that many times. Negative arg -N means move
backward across N balanced expressions.
A sexp in Haml is defined as a line of Haml code as well as any
lines nested beneath it."
(interactive "p")
(or arg (setq arg 1))
(if (and (< arg 0) (not (haml-at-indent-p)))
(while (/= arg 0)
(let ((indent (current-indentation)))
(cl-loop do (haml-forward-through-whitespace (< arg 0))
while (and (not (eobp))
(not (bobp))
(> (current-indentation) indent)))
(unless (eobp)
(setq arg (+ arg (if (> arg 0) -1 1)))))))
(defun haml-backward-sexp (&optional arg)
"Move backward across one nested expression.
With ARG, do it that many times. Negative arg -N means move
forward across N balanced expressions.
A sexp in Haml is defined as a line of Haml code as well as any
lines nested beneath it."
(interactive "p")
(haml-forward-sexp (if arg (- arg) -1)))
(defun haml-up-list (&optional arg)
"Move out of one level of nesting.
With ARG, do this that many times."
(interactive "p")
(or arg (setq arg 1))
(while (> arg 0)
(let ((indent (current-indentation)))
(cl-loop do (haml-forward-through-whitespace t)
while (and (not (bobp))
(>= (current-indentation) indent)))
(setq arg (1- arg))))
(defun haml-down-list (&optional arg)
"Move down one level of nesting.
With ARG, do this that many times."
(interactive "p")
(or arg (setq arg 1))
(while (> arg 0)
(let ((indent (current-indentation)))
(when (<= (current-indentation) indent)
(haml-forward-through-whitespace t)
(error "Nothing is nested beneath this line"))
(setq arg (1- arg))))
(defun haml-mark-sexp ()
"Mark the next Haml block."
(let ((forward-sexp-function 'haml-forward-sexp))
(defun haml-mark-sexp-but-not-next-line ()
"Mark the next Haml block, but not the next line.
Put the mark at the end of the last line of the sexp rather than
the first non-whitespace character of the next line."
(goto-char (mark))
(unless (eobp)
(forward-line -1)
;; Indentation and electric keys
(defvar haml-empty-elements
'("area" "base" "br" "col" "command" "embed" "hr" "img" "input"
"keygen" "link" "meta" "param" "source" "track" "wbr")
"A list of html elements which may not contain content.
(defun haml-unnestable-tag-p ()
"Return t if the current line is an empty element tag, or one with content."
(when (looking-at haml-tag-beg-re)
(goto-char (match-end 0))
(or (string-match-p (concat "%" (regexp-opt haml-empty-elements) "\\b")
(match-string 1))
(when (looking-at "[{(]")
(ignore-errors (forward-sexp)))
(looking-at "\\(?:=\\|==\\| \\)[[:blank:]]*[^[:blank:]\r\n]+"))))))
(defun haml-indent-p ()
"Return t if the current line can have lines nested beneath it."
(let ((attr-props (haml-parse-multiline-attr-hash)))
(if attr-props
(if (haml-unclosed-attr-hash-p)
(cdr (assq 'hash-indent attr-props))
(+ (cdr (assq 'indent attr-props)) haml-indent-offset))
(unless (or (haml-unnestable-tag-p))
(cl-loop for opener in haml-block-openers
if (looking-at opener) return t
finally return nil)))))
(cl-defun haml-parse-multiline-attr-hash ()
"Parses a multiline attribute hash, and returns
an alist with the following keys:
INDENT is the indentation of the line beginning the hash.
HASH-INDENT is the indentation of the first character
within the attribute hash.
POINT is the character position at the beginning of the line
beginning the hash."
(while t
(if (looking-at (concat haml-tag-beg-re "\\([{(]\\)"))
(goto-char (1- (match-end 0)))
(haml-limited-forward-sexp (save-excursion (end-of-line) (point)))
(cl-return-from haml-parse-multiline-attr-hash
(when (or (string-equal (match-string 1) "(") (eq (char-before) ?,))
`((indent . ,(current-indentation))
(hash-indent . ,(- (match-end 0) (match-beginning 0)))
(point . ,(match-beginning 0))))))
(when (bobp) (cl-return-from haml-parse-multiline-attr-hash))
(forward-line -1)
(unless (haml-unclosed-attr-hash-p)
(cl-return-from haml-parse-multiline-attr-hash))))))
(cl-defun haml-unclosed-attr-hash-p ()
"Return t if this line has an unclosed attribute hash, new or old."
(when (eq (char-before) ?,) (cl-return-from haml-unclosed-attr-hash-p t))
(re-search-backward "(\\|^")
(haml-move "(")
(cl-defun haml-parse-new-attr-hash (&optional (fn (lambda (type beg end) ())))
"Parse a new-style attribute hash on this line, and returns
t if it's not finished on the current line.
FN should take three parameters: TYPE, BEG, and END.
TYPE is the type of text parsed ('name or 'value)
and BEG and END delimit that text in the buffer."
(let ((eol (save-excursion (end-of-line) (point))))
(while (not (haml-move ")"))
(haml-move "[ \t]*")
(unless (haml-move "[a-z0-9_:\\-]+")
(cl-return-from haml-parse-new-attr-hash (haml-move "[ \t]*$")))
(funcall fn 'name (match-beginning 0) (match-end 0))
(haml-move "[ \t]*")
(when (haml-move "=")
(haml-move "[ \t]*")
(unless (looking-at "[\"'@a-z0-9]") (cl-return-from haml-parse-new-attr-hash))
(let ((beg (point)))
(haml-limited-forward-sexp eol)
(funcall fn 'value beg (point)))
(haml-move "[ \t]*")))
(defun haml-compute-indentation ()
"Calculate the maximum sensible indentation for the current line."
(if (bobp) (list 0 nil)
(haml-forward-through-whitespace t)
(let ((indent (funcall haml-indent-function)))
((consp indent) indent)
((integerp indent) (list indent t))
(indent (list (+ (current-indentation) haml-indent-offset) nil))
(t (list (current-indentation) nil)))))))
(defun haml-indent-region (start end)
"Indent each nonblank line in the region.
This is done by indenting the first line based on
`haml-compute-indentation' and preserving the relative
indentation of the rest of the region. START and END specify the
region to indent.
If this command is used multiple times in a row, it will cycle
between possible indentations."
(goto-char end)
(setq end (point-marker))
(goto-char start)
(let (this-line-column current-column
(if (and (equal last-command this-command) (/= (current-indentation) 0))
(* (/ (1- (current-indentation)) haml-indent-offset) haml-indent-offset)
(car (haml-compute-indentation)))))
(while (< (point) end)
(setq this-line-column next-line-column
current-column (current-indentation))
;; Delete whitespace chars at beginning of line
(unless (eolp)
(setq next-line-column (save-excursion
(cl-loop do (forward-line 1)
while (and (not (eobp)) (looking-at "^[ \t]*$")))
(+ this-line-column
(- (current-indentation) current-column))))
;; Don't indent an empty line
(unless (eolp) (indent-to this-line-column)))
(forward-line 1)))
(move-marker end nil)))
(defun haml-indent-line ()
"Indent the current line.
The first time this command is used, the line will be indented to the
maximum sensible indentation. Each immediately subsequent usage will
back-dent the line by `haml-indent-offset' spaces. On reaching column
0, it will cycle back to the maximum sensible indentation."
(interactive "*")
(let ((ci (current-indentation))
(cc (current-column)))
(cl-destructuring-bind (need strict) (haml-compute-indentation)
(if (and (not strict) (equal last-command this-command) (/= ci 0))
(indent-to (* (/ (1- ci) haml-indent-offset) haml-indent-offset))
(indent-to need))))
(when (< (current-column) (current-indentation))
(forward-to-indentation 0))))
(defun haml-reindent-region-by (n)
"Add N spaces to the beginning of each line in the region.
If N is negative, will remove the spaces instead. Assumes all
lines in the region have indentation >= that of the first line."
(let* ((ci (current-indentation))
(concat "^"
(if indent-tabs-mode
(concat (make-string (/ ci tab-width) ?\t)
(make-string (mod ci tab-width) ?\t))
(make-string ci ?\s)))))
(while (re-search-forward indent-rx (mark) t)
(let ((ci (current-indentation)))
(indent-to (max 0 (+ ci n))))))))
(defun haml-electric-backspace (arg)
"Delete characters or back-dent the current line.
If invoked following only whitespace on a line, will back-dent
the line and all nested lines to the immediately previous
multiple of `haml-indent-offset' spaces. With ARG, do it that
many times.
Set `haml-backspace-backdents-nesting' to nil to just back-dent
the current line."
(interactive "*p")
(if (or (/= (current-indentation) (current-column))
(looking-at "^[ \t]+$")))
(backward-delete-char arg)
(if haml-backspace-backdents-nesting
(set-mark (save-excursion (end-of-line) (point))))
(haml-reindent-region-by (* (- arg) haml-indent-offset)))
(defun haml-kill-line-and-indent ()
"Kill the current line, and re-indent all lines nested beneath it."
(kill-line 1)
(haml-reindent-region-by (* -1 haml-indent-offset)))
(defun haml-indent-string ()
"Return the indentation string for `haml-indent-offset'."
(mapconcat 'identity (make-list haml-indent-offset " ") ""))
(add-to-list 'auto-mode-alist '("\\.haml\\'" . haml-mode))
;; Local Variables:
;; coding: utf-8
;; byte-compile-warnings: (not cl-functions)
;; eval: (checkdoc-minor-mode 1)
;; End:
(provide 'haml-mode)
;;; haml-mode.el ends here