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From: torek@elf.ee.lbl.gov (Chris Torek)
Newsgroups: comp.editors
Subject: Re: One user's editor wish list
Message-ID: <11200@dog.ee.lbl.gov>
Date: 20 Mar 91 21:30:06 GMT
References: <1991Feb22.134323.20410@scrumpy@.bnr.ca> <11032@dog.ee.lbl.gov> <1991Mar20.191434.5634@scrumpy@.bnr.ca>
Reply-To: torek@elf.ee.lbl.gov (Chris Torek)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 91
X-Local-Date: Wed, 20 Mar 91 13:30:06 PST

In article <1991Mar20.191434.5634@scrumpy@.bnr.ca>
bnrmtl!lewis@larry.mcrcim.mcgill.edu writes:
[`non printing characters']
>What I mean is being able to add/remove them from file.  Of course they have
>to be made visible somehow.  The way vi does this is fine (except for tabs
>cause I don't see them - but maybe this can be changed); with emacs I don't
>know what it looks like, but I'm sure it's fine too.

I will not attempt to guess how different Emacsen handle tabs (my own
private version makes them `tab to column-mod-n' where n can be set on
a per file basis; if you set n to zero or negative, tabs are just
another control character).  Vi has something called `list' mode in
which tabs are shown as ^I:

	:set list

turns this on, and

	:set nolist

turns it off.  In list mode end-of-line is also signified as `$'.

[rings]
>This is an XEDIT concept, it means simply    +-->  file A ---> file B ---+
>that the files are organized in a ring:      |                           |
>(and a single keystroke typically            +---  file C <--- file D <--+
>moves you from one file to the next)

Ah: in Emacs you just bring up ten zillion windows and select amongst
them any way you like.  In vi, `:n' (or :next) goes to the next file.
There is no convenient way to back up (control-^ or :e# switches to the
`current alternate file', which is the previous file after a :n, but
you cannot get any further back than that).  When you reach the end,
or want to restart, `:rew' (:rewind) takes you back to the first.
At any time, :args will show the arguments with [] around the current
file.

>>>     Should be able to name multiple files on command line, e.g.  ed *.c.

>> Everything does this.

>Well not on MS-DOS unless I'm really out of it.

I guess I should have said `Every sane Unix editor'---VMS EDT apparently
also does not.

>[why does mail start one editor per file]

This is the fault of whoever wrote mail;

>(well, true, it would have to create many temporary files)?

this is a likely reason.

>> Vi allows piping through external programs to [fill lines]
>
>That's fine, but what if I only want to reflow a single paragraph, not the
>whole file.

You type {!}fmt and hit return: { means `move back a paragraph' (i.e.,
to the beginning of this one), ! means `filter' (pipe), } means `move
forward a paragraph', and fmt is the `external program' that does it.
If you like,

	map #1 {!}fmt^M

in a .exrc or EXINIT will bind `function key 1' (if it exists, and is
described in termcap) to this.

One problem with this, again, is vi's limited understanding of `paragraph'
(trailing whitespace on a blank line means that line does not separate
paragraphs).

One thing missing from some non-Unix editors is `tags': vi and Emacsen
generally have the notion of a `tags file', which contains the names
and `locators' for things in a program.  Typing `:tag foo' means `find
the tag for foo', and ^] means `find the tag for the word under the cursor'
(in vi; Emacs tags generally are somewhat different).  Tags are mainly
useful for navigating around large programs.

Tags locators are regular expressions, rather than line numbers, so that
most changes to the source do not outdate them.

Many vi tags implementations have an annoying bug: selecting a tag that
appears in the current file fails if you have `nowrapscan' set and the
tag appears before the current cursor position.  This is easily fixed
in the source: just save and restore nowrapscan, and turn it off for
the tag search.
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 415 486 5427)
Berkeley, CA		Domain:	torek@ee.lbl.gov