Re: PATCH: enhanced word widgets

[Peter Stephenson <pws@xxxxxxx>]

"Bart Schaefer" wrote:
> I want the definition of a "word" to be context-sensitive.  For example:
> If the cursor is within a shell word that contains a "/" character, then
> I want "ZLE words" to be pathname components (and transpose-words should
> transpose around the nearest "/" either under the cursor or to the left);
> but if the cursor is between two shell words, then I want "words" to be
> shell words, e.g., pathnames including the slashes.

OK, I think this does pretty much what you want.  (Luckily I was working
on a scatternet scheduling problem, so I was easily diverted.)  Zefram
is quite right but his point leads to a complete rewrite of the parser
rather than a quick ten-minute rewrite of the shell function...

No documentation yet and it won't be committed until we decide what the
neatest way of doing this is.

Set the style word-context to pairs of words: a pattern, and a
subcontext.  The function then tests against the patterns in order.

- If the cursor is in a command argument the pattern will be tested
  against the word (with any quotes stripped, so foo, \foo, 'foo' "foo"
  will all give you foo to match against --- I can remove this, but it
  seemed more convenient with it).
- If the cursor is in whitespace between words, it will be tested
  against the whitespace character under the cursor.
- If it is at the end of the buffer, it will be tested against the empty
  string.
- For reasons best known to the lexical analyser, the pattern is tested
  against `;' if you are at the end of a line when there are more to
  follow (unfortunately due to the unquoting this looks the same as a
  real semicolon in quotes).  I suppose I could sensibly trap this
  before the unquoting and turn it into a newline.

If a pattern matches, the corresponding subcontext is appended (with the
traditional colon) to the end of the current context.

I tried this out with the context array:

zstyle ':zle:*' word-context "[[:space:]]" whitespace "*/*" \
    filename "" end "*" other

(though all you need for the suggested use are the `filename' element
plus a suitable default and `other' is completely redundant (it's an
insignificant other)) and

zstyle ':zle:transpose-words:whitespace' word-style shell
zstyle ':zle:transpose-words:filename' word-style normal
zstyle ':zle:transpose-words:filename' word-chars ''

so if you are in a filename --- the character under the cursor is part
of a word which includes a slash --- you get bash-style behaviour, if
you are in whitespace, you get shell-word behaviour, and if you are in
any other word you get the default behaviour.


Index: Functions/Zle/match-words-by-style
===================================================================
RCS file: /cvsroot/zsh/zsh/Functions/Zle/match-words-by-style,v
retrieving revision 1.1
diff -u -r1.1 match-words-by-style
--- Functions/Zle/match-words-by-style	28 Mar 2003 11:34:30 -0000	1.1
+++ Functions/Zle/match-words-by-style	28 Mar 2003 18:46:56 -0000
@@ -62,12 +62,47 @@
 emulate -L zsh
 setopt extendedglob
 
-local wordstyle spacepat wordpat1 wordpat2 opt charskip
+local wordstyle spacepat wordpat1 wordpat2 charskip
 local match mbegin mend pat1 pat2 word1 word2 ws1 ws2 ws3 skip
-local MATCH MBEGIN MEND
+local MATCH MBEGIN MEND pattern subcontext
+local -a wordcontext
 
 if [[ -z $curcontext ]]; then
     local curcontext=:zle:match-words-by-style
+fi
+
+if zstyle -a $curcontext word-context wordcontext; then
+    # Pretend line so far is a complete set of words...
+    bufwords=(${(z)LBUFFER})
+    word1=${#bufwords}
+    # Word either before or including cursor
+    pat1=$bufwords[-1]
+    # If we get more words by adding in the cursor, we're at the
+    # start of the next word.
+    wordpat1="$LBUFFER$RBUFFER[1]"
+    bufwords=(${(z)wordpat1})
+    word2=${#bufwords}
+    pat2=$bufwords[-1]
+    bufwords=(${(z)BUFFER})
+    if (( word1 != word2 )); then
+	# At start of word2
+	wordpat2=${(Q)bufwords[$word2]}
+    elif [[ ${#bufwords[$word1]} > ${#pat1} ]]; then
+	# Word is longer when including whole buffer.
+	# How beautiful life is now you're in the word.
+	# Strip quotes in order to test actual argument
+	# (except we haven't done expansion on it).
+	wordpat2=${(Q)bufwords[$word1]}
+    else
+	# We are not in the word.  Just use character at cursor position.
+	wordpat2=$RBUFFER[1]
+    fi
+    for pattern subcontext in "${wordcontext[@]}"; do
+	if [[ $wordpat2 = ${~pattern} ]]; then
+	    curcontext+=":$subcontext"
+	    break
+	fi
+    done
 fi
 
 zstyle -s $curcontext word-style wordstyle

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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