From 2d0c476fe02494837c6d0e035807e93dfd54677b Mon Sep 17 00:00:00 2001 From: Dima Kogan Date: Sun, 25 Dec 2016 11:35:26 -0800 Subject: [PATCH 1/2] comint-insert-previous-argument counts args from the start or from the end This function is invoked in shell-mode by the user, and is meant to emulate what M-. does in zsh and bash: it inserts an argument from a previous command. Without a prefix argument, it inserts the last arg from the previous command; with an argument INDEX, it inserts the INDEX-th argument. bash counds from the start, while zsh counts from the end. This patch adds a variable `comint-insert-previous-argument-from-end' that emulates the zsh behavior if non-nil. * lisp/comint.el (comint-arguments): can take in negative arguments to count from the end, same as indexing in python. (comint-insert-previous-argument): if comint-insert-previous-argument-from-end is non-nil, INDEX counts arguments from the end; if nil, from the beginning --- lisp/comint.el | 49 ++++++++++++++++++++++++++++++++++++------------- 1 file changed, 36 insertions(+), 13 deletions(-) diff --git a/lisp/comint.el b/lisp/comint.el index b9c65b0..171caef 100644 --- a/lisp/comint.el +++ b/lisp/comint.el @@ -1660,12 +1660,13 @@ comint-delim-arg (defun comint-arguments (string nth mth) "Return from STRING the NTH to MTH arguments. -NTH and/or MTH can be nil, which means the last argument. -Returned arguments are separated by single spaces. -We assume whitespace separates arguments, except within quotes -and except for a space or tab that immediately follows a backslash. -Also, a run of one or more of a single character -in `comint-delimiter-argument-list' is a separate argument. +NTH and/or MTH can be nil, which means the last argument. NTH +and MTH can be <0 to count from the end; -1 means last argument. +Returned arguments are separated by single spaces. We assume +whitespace separates arguments, except within quotes and except +for a space or tab that immediately follows a backslash. Also, a +run of one or more of a single character in +`comint-delimiter-argument-list' is a separate argument. Argument 0 is the command name." ;; The first line handles ordinary characters and backslash-sequences ;; (except with w32 msdos-like shells, where backslashes are valid). @@ -1687,7 +1688,7 @@ comint-arguments (count 0) beg str quotes) ;; Build a list of all the args until we have as many as we want. - (while (and (or (null mth) (<= count mth)) + (while (and (or (null mth) (< mth 0) (<= count mth)) (string-match argpart string pos)) ;; Apply the `literal' text property to backslash-escaped ;; characters, so that `comint-delim-arg' won't break them up. @@ -1714,8 +1715,14 @@ comint-arguments args (if quotes (cons str args) (nconc (comint-delim-arg str) args)))) (setq count (length args)) - (let ((n (or nth (1- count))) - (m (if mth (1- (- count mth)) 0))) + (let ((n (cond + ((null nth) (1- count)) + ((>= nth 0) nth) + (t (+ count nth)))) + (m (cond + ((null mth) 0) + ((>= mth 0) (1- (- count mth))) + (t (1- (- mth)))))) (mapconcat (function (lambda (a) a)) (nthcdr n (nreverse (nthcdr m args))) " ")))) @@ -2634,8 +2641,21 @@ comint-previous-prompt (defvar-local comint-insert-previous-argument-last-start-pos nil) (defvar-local comint-insert-previous-argument-last-index nil) -;; Needs fixing: -;; make comint-arguments understand negative indices as bash does +(defvar-local comint-insert-previous-argument-from-end nil + "If nil, the INDEX argument to +`comint-insert-previous-argument' refers to the INDEX-th +argument, counting from the beginning; if non-nil, counting from +the end. This exists to emulate the bahavior of `M-number M-.' +in bash and zsh: in bash, `number' counts from the +beginning (variable in nil), while in zsh it counts from the end. +This variable is buffer-local. To get the zsh behavior in `M-x +shell' sessions, do something like this: + + (add-hook + 'shell-mode-hook + (lambda () + (setq comint-insert-previous-argument-from-end t)))") + (defun comint-insert-previous-argument (index) "Insert the INDEXth argument from the previous Comint command-line at point. Spaces are added at beginning and/or end of the inserted string if @@ -2643,8 +2663,8 @@ comint-insert-previous-argument Interactively, if no prefix argument is given, the last argument is inserted. Repeated interactive invocations will cycle through the same argument from progressively earlier commands (using the value of INDEX specified -with the first command). -This command is like `M-.' in bash." +with the first command). Values of INDEX<0 count from the end, so INDEX=-1 +is the last argument. This command is like `M-.' in bash." (interactive "P") (unless (null index) (setq index (prefix-numeric-value index))) @@ -2654,6 +2674,9 @@ comint-insert-previous-argument (setq index comint-insert-previous-argument-last-index)) (t ;; This is a non-repeat invocation, so initialize state. + (when (and index + comint-insert-previous-argument-from-end) + (setq index (- index))) (setq comint-input-ring-index nil) (setq comint-insert-previous-argument-last-index index) (when (null comint-insert-previous-argument-last-start-pos) -- 2.10.1