;;; smie.el --- Simple Minded Indentation Engine -*- lexical-binding: t -*-
-;; Copyright (C) 2010-2015 Free Software Foundation, Inc.
+;; Copyright (C) 2010-2016 Free Software Foundation, Inc.
;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
;; Keywords: languages, lisp, internal, parsing, indentation
(cl-incf smie-warning-count))
(puthash key val table))))
-(put 'smie-precs->prec2 'pure t)
(defun smie-precs->prec2 (precs)
"Compute a 2D precedence table from a list of precedences.
PRECS should be a list, sorted by precedence (e.g. \"+\" will
come before \"*\"), of elements of the form \(left OP ...)
or (right OP ...) or (nonassoc OP ...) or (assoc OP ...). All operators in
one of those elements share the same precedence level and associativity."
+ (declare (pure t))
(let ((prec2-table (make-hash-table :test 'equal)))
(dolist (prec precs)
(dolist (op (cdr prec))
(smie-set-prec2tab prec2-table other-op op op1)))))))
prec2-table))
-(put 'smie-merge-prec2s 'pure t)
(defun smie-merge-prec2s (&rest tables)
+ (declare (pure t))
(if (null (cdr tables))
(car tables)
(let ((prec2 (make-hash-table :test 'equal)))
table))
prec2)))
-(put 'smie-bnf->prec2 'pure t)
(defun smie-bnf->prec2 (bnf &rest resolvers)
"Convert the BNF grammar into a prec2 table.
BNF is a list of nonterminal definitions of the form:
- \(NONTERM RHS1 RHS2 ...)
+ (NONTERM RHS1 RHS2 ...)
where each RHS is a (non-empty) list of terminals (aka tokens) or non-terminals.
Not all grammars are accepted:
- an RHS cannot be an empty list (this is not needed, since SMIE allows all
be either:
- a precs table (see `smie-precs->prec2') to resolve conflicting constraints,
- a constraint (T1 REL T2) where REL is one of = < or >."
+ (declare (pure t))
;; FIXME: Add repetition operator like (repeat <separator> <elems>).
;; Maybe also add (or <elem1> <elem2>...) for things like
;; (exp (exp (or "+" "*" "=" ..) exp)).
;; (t (cl-assert (eq v '=))))))))
;; prec2))
-(put 'smie-prec2->grammar 'pure t)
(defun smie-prec2->grammar (prec2)
"Take a 2D precedence table and turn it into an alist of precedence levels.
PREC2 is a table as returned by `smie-precs->prec2' or
`smie-bnf->prec2'."
+ (declare (pure t))
;; For each operator, we create two "variables" (corresponding to
;; the left and right precedence level), which are represented by
;; cons cells. Those are the very cons cells that appear in the
(cons (pcase (cdr x)
(`closer (cddr (assoc token table)))
(`opener (cdr (assoc token table))))))
- (cl-assert (numberp (car cons)))
- (setf (car cons) (list (car cons)))))
+ ;; `cons' can be nil for openers/closers which only contain
+ ;; "atomic" elements.
+ (when cons
+ (cl-assert (numberp (car cons)))
+ (setf (car cons) (list (car cons))))))
(let ((ca (gethash :smie-closer-alist prec2)))
(when ca (push (cons :smie-closer-alist ca) table)))
;; (smie-check-grammar table prec2 'step3)
(goto-char pos)
(throw 'return
(list t epos
- (buffer-substring-no-properties
- epos
- (+ epos (if (< (point) epos) -1 1))))))))
+ (unless (= (point) epos)
+ (buffer-substring-no-properties
+ epos
+ (+ epos (if (< (point) epos) -1 1)))))))))
(if (eq pos (point))
;; We did not move, so let's abort the loop.
(throw 'return (list t (point))))))
nil: we skipped over an identifier, matched parentheses, ..."
(smie-next-sexp
(indirect-function smie-backward-token-function)
- (indirect-function #'backward-sexp)
+ (lambda (n)
+ (if (bobp)
+ ;; Arguably backward-sexp should signal this error for us.
+ (signal 'scan-error
+ (list "Beginning of buffer" (point) (point)))
+ (backward-sexp n)))
(indirect-function #'smie-op-left)
(indirect-function #'smie-op-right)
halfsexp))
;;; Miscellaneous commands using the precedence parser.
-(defun smie-backward-sexp-command (&optional n)
+(defun smie-backward-sexp-command (n)
"Move backward through N logical elements."
(interactive "^p")
(smie-forward-sexp-command (- n)))
-(defun smie-forward-sexp-command (&optional n)
+(defun smie-forward-sexp-command (n)
"Move forward through N logical elements."
(interactive "^p")
(let ((forw (> n 0))
- :elem, in which case the function should return either:
- the offset to use to indent function arguments (ARG = `arg')
- the basic indentation step (ARG = `basic').
+ - the token to use (when ARG = `empty-line-token') when we don't know how
+ to indent an empty line.
- :list-intro, in which case ARG is a token and the function should return
non-nil if TOKEN is followed by a list of expressions (not separated by any
token) rather than an expression.
(forward-comment (- (point)))
(<= (point) bol))))
+(defun smie-indent--current-column ()
+ "Like `current-column', but if there's a comment before us, use that."
+ ;; This is used, so that when we align elements, we don't get
+ ;; toto = { /* foo, */ a,
+ ;; b }
+ ;; but
+ ;; toto = { /* foo, */ a,
+ ;; b }
+ (let ((pos (point))
+ (lbp (line-beginning-position)))
+ (save-excursion
+ (unless (and (forward-comment -1) (>= (point) lbp))
+ (goto-char pos))
+ (current-column))))
+
;; Dynamically scoped.
(defvar smie--parent) (defvar smie--after) (defvar smie--token)
;; So we use a heuristic here, which is that we only use virtual
;; if the parent is tightly linked to the child token (they're
;; part of the same BNF rule).
- (if (car parent) (current-column) (smie-indent-virtual)))))))))))
+ (if (car parent)
+ (smie-indent--current-column)
+ (smie-indent-virtual)))))))))))
(defun smie-indent-comment ()
"Compute indentation of a comment."
(+ (smie-indent-virtual) (smie-indent--offset 'basic))) ;
(t (smie-indent-virtual)))))) ;An infix.
+(defun smie-indent-empty-line ()
+ "Indentation rule when there's nothing yet on the line."
+ ;; Without this rule, SMIE assumes that an empty line will be filled with an
+ ;; argument (since it falls back to smie-indent-sexps), which tends
+ ;; to indent far too deeply.
+ (when (eolp)
+ (let ((token (or (funcall smie-rules-function :elem 'empty-line-token)
+ ;; FIXME: Should we default to ";"?
+ ;; ";"
+ )))
+ (when (assoc token smie-grammar)
+ (smie-indent-keyword token)))))
+
(defun smie-indent-exps ()
;; Indentation of sequences of simple expressions without
;; intervening keywords or operators. E.g. "a b c" or "g (balbla) f".
;; There's a previous element, and it's not special (it's not
;; the function), so let's just align with that one.
(goto-char (car positions))
- (current-column))
+ (smie-indent--current-column))
((cdr positions)
;; We skipped some args plus the function and bumped into something.
;; Align with the first arg.
(goto-char (cadr positions))
- (current-column))
+ (smie-indent--current-column))
(positions
;; We're the first arg.
(goto-char (car positions))
;; We used to use (smie-indent-virtual), but that
;; doesn't seem right since it might then indent args less than
;; the function itself.
- (current-column)))))))
+ (smie-indent--current-column)))))))
(defvar smie-indent-functions
'(smie-indent-fixindent smie-indent-bob smie-indent-close
smie-indent-comment smie-indent-comment-continue smie-indent-comment-close
smie-indent-comment-inside smie-indent-inside-string
smie-indent-keyword smie-indent-after-keyword
- smie-indent-exps)
+ smie-indent-empty-line smie-indent-exps)
"Functions to compute the indentation.
Each function is called with no argument, shouldn't move point, and should
return either nil if it has no opinion, or an integer representing the column