lisp/lispindent.lisp @ 4237c4d29d58

;; Fork of lispindent https://github.com/ds26gte/scmindent
;; Some day I need to rewrite this with smug or something, jesus.


;Dorai Sitaram
;Oct 8, 1999
;last change 2014-09-16

;this script takes lines of Lisp or Scheme code from its
;stdin and produces an indented version thereof on its
;stdout

(defun safe-read (stream)
  (let ((*read-eval* nil))
    (read stream nil)))

(defun safe-read-from-string (string)
  (let ((*read-eval* nil))
    (read-from-string string)))


(defvar *lisp-keywords* '())
(defvar *labels-keywords* '(labels flet macrolet labels* flet* labels-memoized))
(defvar *labels2-keywords* '(state-machine))
(defvar *lambda-list-keywords* '(defun defmethod defmacro define-compiler-macro defun* defmacro-clause defmacro-driver))
(defvar *case-keywords* '(cond case))


(defun define-with-lisp-indent-number (n syms)
  (dolist (sym syms)
    (let* ((x (symbol-name sym))
           (c (assoc x *lisp-keywords* :test #'string-equal)))
      (unless c
        (push (setq c (cons x nil)) *lisp-keywords*))
      (setf (cdr c) n))))

(define-with-lisp-indent-number 0
  '(block
    handler-bind
    loop))

(define-with-lisp-indent-number 1
  '(case
    defpackage do-all-symbols do-external-symbols dolist do-symbols dotimes
    ecase etypecase eval-when
    flet
    handler-case
    labels lambda let let* let-values
    macrolet
    prog1
    typecase
    unless unwind-protect
    when with-input-from-string with-open-file with-open-socket
    with-open-stream with-output-to-string))

(define-with-lisp-indent-number 2
  '(assert
    defun destructuring-bind do do*
    if
    multiple-value-bind
    with-slots))


(defparameter *config-files*
  (list (merge-pathnames ".lispwords" (user-homedir-pathname))
        ".lispwords"
        ".notmylispwords"))


(defun source-config-files ()
  (dolist (path *config-files*)
    (with-open-file (i path :if-does-not-exist nil)
      (when i
        (loop
          (let ((w (or (safe-read i) (return))))
            (define-with-lisp-indent-number (car w) (cdr w))))))))


(defstruct lparen
  word
  spaces-before
  num-aligned-subforms
  (num-finished-subforms 0)
  (num-processed-subforms 0))


(defun past-next-token (s i n)
  (let ((escapep nil))
    (loop
      (when (>= i n) (return i))
      (let ((c (char s i)))
        (cond (escapep (setq escapep nil))
              ((char= c #\\) (setq escapep t))
              ((char= c #\#)
               (let ((j (+ i 1)))
                 (if (>= j n) (return i)
                   (let ((c (char s j)))
                     (cond ((char= c #\\) (setq escapep t i j))
                           (t (return i)))))))
              ((member c '(#\space #\tab #\( #\) #\[ #\] #\" #\' #\` #\, #\;))
               (return i))))
      (incf i))))

(defun lisp-indent-number (s &optional (possible-keyword-p t))
  (or (cdr (assoc s *lisp-keywords* :test #'string-equal))
      (if (zerop (or (search "def" s :test #'char-equal)
                     (search "with-" s :test #'char-equal)
                     -1))
        0
        (if possible-keyword-p
          (let ((p (position #\: s :from-end t)))
            (if p
              (lisp-indent-number (subseq s (1+ p)) nil)
              -1))
          -1))))

(defun literal-token-p (s)
  (let ((colon-pos (position #\: s)))
    (if colon-pos
        (if (= colon-pos 0) t nil)
      (let ((s (safe-read-from-string s)))
        (or (eql t s) (characterp s) (numberp s) (stringp s))))))

;(trace lisp-indent-number literal-token-p read-from-string past-next-token)

(defun current-word (s i n)
  (let ((j (past-next-token s i n)))
    (when (not (= i j))
      (subseq s i j))))


(defun in-labels-p (stack)
  (let ((target (cadr stack)))
    (or (and target
             (member (lparen-word target) *labels-keywords*
                     :key #'symbol-name :test #'string-equal)
             (= (lparen-num-processed-subforms target) 0))
        (and target
             (member (lparen-word target) *labels2-keywords*
                     :key #'symbol-name :test #'string-equal)
             (= (lparen-num-processed-subforms target) 1)))))

(defun in-lambda-list-p (stack)
  (let ((target (car stack)))
    (and target
         (member (lparen-word target) *lambda-list-keywords*
                 :key #'symbol-name :test #'string-equal)
         (= (lparen-num-processed-subforms target) 0))))

(defun in-case-p (stack)
  (let ((target (car stack)))
    (and target
         (member (lparen-word target) *case-keywords*
                 :key #'symbol-name :test #'string-equal))))



(defun calc-subindent (stack s i n)
  (let* ((j (past-next-token s i n))
         (num-aligned-subforms 0)
         (left-indent
           (if (= j i) 1
             (let ((w (subseq s i j)))
               (if (and (>= i 2) (member (char s (- i 2)) '(#\' #\`))) 2
                 (let ((nas (if (in-labels-p stack)
                              1
                              (lisp-indent-number w))))
                   (cond ((or (in-lambda-list-p stack)
                              (in-case-p stack)) 1)
                         ((>= nas 0) (setq num-aligned-subforms nas)
                          2)
                         ((literal-token-p w) 1)
                         ((= j n) 2)
                         (t (+ (- j i) 2)))))))))
    (values left-indent num-aligned-subforms (1- j))))

(defun num-leading-spaces (s)
  (let ((n (length s))
        (i 0) (j 0))
    (loop
      (when (>= i n) (return 0))
      (case (char s i)
        (#\space (incf i) (incf j))
        (#\tab (incf i) (incf j 8))
        (t (return j))))))


(defun string-trim-blanks (s)
  (string-trim '(#\space #\tab #\newline #\return) s))


(defun indent-lines ()
  (let ((left-i 0)
        (paren-stack '())
        (stringp nil))
    (loop
      (let* ((curr-line (or (read-line nil nil) (return)))
             (leading-spaces (num-leading-spaces curr-line))
             (curr-left-i
               (cond (stringp leading-spaces)
                     ((null paren-stack)
                      (when (= left-i 0) (setq left-i leading-spaces))
                      left-i)
                     (t (let* ((lp (car paren-stack))
                               (nas (lparen-num-aligned-subforms lp))
                               (nfs (lparen-num-finished-subforms lp))
                               (extra-w 0))
                          (when (< nfs nas) ;(and (>= nas 0) (< nfs nas))
                            (incf (lparen-num-finished-subforms lp))
                            (setq extra-w 2))
                          (+ (lparen-spaces-before lp)
                             extra-w))))))
        (setq curr-line (string-trim-blanks curr-line))
        (when (not (string= curr-line "")) ; don't add "trailing" whitespace
          (dotimes (k curr-left-i) (write-char #\space)))
        (princ curr-line)
        (terpri)
        ;
        (let ((i 0) (n (length curr-line)) (escapep nil)
              (inter-word-space-p nil))
          (loop
            (when (>= i n) (return))
            (let ((c (char curr-line i)))
              (cond (escapep (setq escapep nil))
                    ((char= c #\\) (setq escapep t))
                    (stringp (when (char= c #\") (setq stringp nil)))
                    ((char= c #\;) (return))
                    ((char= c #\") (setq stringp t))
                    ((member c '(#\space #\tab) :test #'char=)
                     (unless inter-word-space-p
                       (setq inter-word-space-p t)
                       (let ((lp (car paren-stack)))
                         (when lp
                           (incf (lparen-num-finished-subforms lp))))))
                    ((member c '(#\( #\[) :test #'char=)
                     (setq inter-word-space-p nil)
                     (multiple-value-bind (left-indent num-aligned-subforms j)
                         (calc-subindent paren-stack curr-line (1+ i) n)
                       (push
                         (make-lparen :word (current-word curr-line (1+ i) n)
                                      :spaces-before (+ i curr-left-i left-indent)
                                      :num-aligned-subforms num-aligned-subforms)
                         paren-stack)
                       (setq i j)))
                    ((member c '(#\) #\]) :test #'char=)
                     (setq inter-word-space-p nil)
                     (cond (paren-stack (pop paren-stack))
                           (t (setq left-i 0)))
                     (let ((lp (car paren-stack)))
                       (when lp
                         (incf (lparen-num-processed-subforms lp)))))
                    (t (setq inter-word-space-p nil)))
              (incf i))))))))


(defun main ()
  (source-config-files)
  (indent-lines)
  t)

(defun build ()
  (sb-ext:save-lisp-and-die "lispindent"
                            :toplevel 'main
                            :executable t))