diff options
Diffstat (limited to 'lisp/emacs-lisp/smie.el')
| -rw-r--r-- | lisp/emacs-lisp/smie.el | 50 |
1 files changed, 41 insertions, 9 deletions
diff --git a/lisp/emacs-lisp/smie.el b/lisp/emacs-lisp/smie.el index 79a2543e1f8..cad7c8419b2 100644 --- a/lisp/emacs-lisp/smie.el +++ b/lisp/emacs-lisp/smie.el @@ -1,6 +1,6 @@ -;;; smie.el --- Simple Minded Indentation Engine +;;; smie.el --- Simple Minded Indentation Engine -*- lexical-binding: t -*- -;; Copyright (C) 2010, 2011 Free Software Foundation, Inc. +;; Copyright (C) 2010-2011 Free Software Foundation, Inc. ;; Author: Stefan Monnier <monnier@iro.umontreal.ca> ;; Keywords: languages, lisp, internal, parsing, indentation @@ -84,6 +84,26 @@ ;; - Maybe accept two juxtaposed non-terminals in the BNF under the condition ;; that the first always ends with a terminal, or that the second always ;; starts with a terminal. +;; - Permit EBNF-style notation. +;; - If the grammar has conflicts, the only way is to make the lexer return +;; different tokens for the different cases. This extra work performed by +;; the lexer can be costly and unnecessary: we perform this extra work every +;; time we find the conflicting token, regardless of whether or not the +;; difference between the various situations is relevant to the current +;; situation. E.g. we may try to determine whether a ";" is a ";-operator" +;; or a ";-separator" in a case where we're skipping over a "begin..end" pair +;; where the difference doesn't matter. For frequently occurring tokens and +;; rarely occurring conflicts, this can be a significant performance problem. +;; We could try and let the lexer return a "set of possible tokens +;; plus a refinement function" and then let parser call the refinement +;; function if needed. +;; - Make it possible to better specify the behavior in the face of +;; syntax errors. IOW provide some control over the choice of precedence +;; levels within the limits of the constraints. E.g. make it possible for +;; the grammar to specify that "begin..end" has lower precedence than +;; "Module..EndModule", so that if a "begin" is missing, scanning from the +;; "end" will stop at "Module" rather than going past it (and similarly, +;; scanning from "Module" should not stop at a spurious "end"). ;;; Code: @@ -178,7 +198,7 @@ one of those elements share the same precedence level and associativity." ;; Maybe also add (or <elem1> <elem2>...) for things like ;; (exp (exp (or "+" "*" "=" ..) exp)). ;; Basically, make it EBNF (except for the specification of a separator in - ;; the repetition). + ;; the repetition, maybe). (let ((nts (mapcar 'car bnf)) ;Non-terminals (first-ops-table ()) (last-ops-table ()) @@ -209,14 +229,18 @@ one of those elements share the same precedence level and associativity." ;; the trouble, and it lets the writer of the BNF ;; be a bit more sloppy by skipping uninteresting base ;; cases which are terminals but not OPs. - (assert (not (member (cadr rhs) nts))) + (when (member (cadr rhs) nts) + (error "Adjacent non-terminals: %s %s" + (car rhs) (cadr rhs))) (pushnew (cadr rhs) first-ops))) (let ((shr (reverse rhs))) (if (not (member (car shr) nts)) (pushnew (car shr) last-ops) (pushnew (car shr) last-nts) (when (consp (cdr shr)) - (assert (not (member (cadr shr) nts))) + (when (member (cadr shr) nts) + (error "Adjacent non-terminals: %s %s" + (cadr shr) (car shr))) (pushnew (cadr shr) last-ops))))) (push (cons nt first-ops) first-ops-table) (push (cons nt last-ops) last-ops-table) @@ -915,7 +939,7 @@ This uses SMIE's tables and is expected to be placed on `post-self-insert-hook'. ;; anything else than this trigger char, lest we'd blink ;; both when inserting the trigger char and when ;; inserting a subsequent trigger char like SPC. - (or (eq (point) pos) + (or (eq (char-before) last-command-event) (not (memq (char-before) smie-blink-matching-triggers))) (or smie-blink-matching-inners @@ -998,7 +1022,10 @@ the beginning of a line." (unless (numberp (cadr (assoc tok smie-grammar))) (goto-char pos)) (setq smie--parent - (smie-backward-sexp 'halfsexp)))))) + (or (smie-backward-sexp 'halfsexp) + (let (res) + (while (null (setq res (smie-backward-sexp)))) + (list nil (point) (nth 2 res))))))))) (defun smie-rule-parent-p (&rest parents) "Return non-nil if the current token's parent is among PARENTS. @@ -1403,6 +1430,10 @@ should not be computed on the basis of the following token." (and (nth 4 (syntax-ppss)) 'noindent)) +(defun smie-indent-inside-string () + (and (nth 3 (syntax-ppss)) + 'noindent)) + (defun smie-indent-after-keyword () ;; Indentation right after a special keyword. (save-excursion @@ -1476,8 +1507,9 @@ should not be computed on the basis of the following token." (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-keyword smie-indent-after-keyword + 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) "Functions to compute the indentation. Each function is called with no argument, shouldn't move point, and should |