PATCH: bash-transpose-words

PATCH: bash-transpose-words

[Peter Stephenson]

This one I definitely plan to use, I've been frustrated by the other one
too often.

Now what I'd really like is for the cursor to stay at the point between the
words it's transposing instead of hopping around after it, but that
requires either doing the whole thing in a shell function, or some trickery
with marks --- which I still don't trust if text has been moving around,
but I haven't analysed what I don't trust well enough to suggest what needs
fixing.

Index: Doc/Zsh/contrib.yo
===================================================================
RCS file: /cvsroot/zsh/zsh/Doc/Zsh/contrib.yo,v
retrieving revision 1.11
diff -u -r1.11 contrib.yo
--- Doc/Zsh/contrib.yo	2001/07/06 17:25:54	1.11
+++ Doc/Zsh/contrib.yo	2001/07/20 10:45:27
@@ -366,15 +366,17 @@
 tindex(bash-backward-word)
 tindex(bash-kill-word)
 tindex(bash-backward-kill-word)
+tindex(bash-transpowse-words)
 xitem(tt(bash-forward-word), tt(bash-backward-word))
-item(tt(bash-kill-word), tt(bash-backward-kill-word))(
+xitem(tt(bash-kill-word), tt(bash-backward-kill-word))
+item(tt(bash-transpose-words))(
 These work similarly to the corresponding builtin zle functions without the
 `tt(bash-)' prefix, but a word is considered to consist of alphanumeric
 characters only.  If you wish to replace your existing bindings with these
 four widgets, the following is sufficient:
 
 example(for widget in kill-word backward-kill-word \ 
-forward-word backward-word; do 
+forward-word backward-word transpose-words; do 
   autoload bash-$widget 
   zle -N $widget bash-$widget
 done)
Index: Functions/Zle/bash-transpose-words
===================================================================
RCS file: bash-transpose-words
diff -N bash-transpose-words
--- /dev/null	Thu May 24 22:33:05 2001
+++ bash-transpose-words	Fri Jul 20 03:45:27 2001
@@ -0,0 +1,9 @@
+# This implements a bash-style transpose-words.
+# To use,
+#   zle -N bash-transpose-words
+#   bindkey '...' bash-transpose-words
+# or if you wish to replace existing transpose-words bindings,
+#   zle -N transpose-words bash-transpose-words
+
+local WORDCHARS=''
+zle .transpose-words

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Unit 300, Science Park, Milton Road,
Cambridge, CB4 0XL, UK                          Tel: +44 (0)1223 392070


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Re: PATCH: bash-transpose-words

[Bart Schaefer]

On Jul 20, 11:49am, Peter Stephenson wrote:
} 
} Now what I'd really like is for the cursor to stay at the point [...]
} with marks --- which I still don't trust if text has been moving around,
} but I haven't analysed what I don't trust well enough to suggest what needs
} fixing.

The mark in zsh is just an offset in $BUFFER.  In emacs it (effectively)
is a zero-width pseudo-character located between two real characters.
That means you can move stuff around the mark in emacs and it shifts left
or right along with the unchanging characters adjacent to it.  In zsh,
this effect is sometimes mimicked by (in|de)crementing the mark position
as characters are (inserted|deleted), but it is not done consistently.

So given this text:

        echo abcdefg dcba
                     ^
                     cursor and mark both here

In emacs, after transpose-words:

        echo dcba abcdefg
                  ^
                  cursor and mark both here (moved with the space)

But in zsh:

        echo dcba abcdefg
                     ^
                     mark here (same buffer offset), cursor at end

Sven and I had a discussion a while back about the difficulty of keeping
the mark consistent when one can do wholesale assignments to $BUFFER
without passing through the usual zle functions.  It was inconclusive.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net