dollar-double-quoted-argument: Highlight "$foo" better.

Now, «"$42foo"» doesn't highlight the «foo», and «"$bar» highlights the «r».

highlighters/main/main-highlighter.zsh

@@ -260,15 +260,19 @@ _zsh_highlight_main_highlighter_check_path()
 _zsh_highlight_main_highlighter_highlight_string()
 {
   setopt localoptions noksharrays
-  local i j k style varflag
+  local i j k style
   local AA
   # Starting quote is at 1, so start parsing at offset 2 in the string.
   for (( i = 2 ; i < end_pos - start_pos ; i += 1 )) ; do
     (( j = i + start_pos - 1 ))
     (( k = j + 1 ))
     case "$arg[$i]" in
       '$' ) style=$ZSH_HIGHLIGHT_STYLES[dollar-double-quoted-argument]
-            (( varflag = 1))
+            # Look for an alphanumeric parameter name.
+            if [[ ${arg:$i} =~ ^([A-Za-z_][A-Za-z0-9_]*|[0-9]+) ]] ; then
+              (( k += $#MATCH )) # highlight the parameter name
+              (( i += $#MATCH )) # skip past it
+            fi
             ;;
       "\\") style=$ZSH_HIGHLIGHT_STYLES[back-double-quoted-argument]
             for (( c = i + 1 ; c < end_pos - start_pos ; c += 1 )); do
@@ -283,13 +287,8 @@ _zsh_highlight_main_highlighter_highlight_string()
               (( k += 1 )) # Color following char too.
               (( i += 1 )) # Skip parsing the escaped char.
             fi
-              (( varflag = 0 )) # End of variable
-            ;;
-      ([^a-zA-Z0-9_]))
-            (( varflag = 0 )) # End of variable
-            continue
             ;;
-      *) [[ $varflag -eq 0 ]] && continue ;;
+      *) continue ;;
 
     esac
     _zsh_highlight_main_add_region_highlight $j $k $style

highlighters/main/test-data/double-quoted2.zsh

@@ -0,0 +1,37 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2010-2011 zsh-syntax-highlighting contributors
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are permitted
+# provided that the following conditions are met:
+#
+#  * Redistributions of source code must retain the above copyright notice, this list of conditions
+#    and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright notice, this list of
+#    conditions and the following disclaimer in the documentation and/or other materials provided
+#    with the distribution.
+#  * Neither the name of the zsh-syntax-highlighting contributors nor the names of its contributors
+#    may be used to endorse or promote products derived from this software without specific prior
+#    written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# -------------------------------------------------------------------------------------------------
+# -*- mode: zsh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
+# vim: ft=zsh sw=2 ts=2 et
+# -------------------------------------------------------------------------------------------------
+
+# This test checks that the 'r' gets highlighted correctly.  Do not append to the BUFFER.
+BUFFER=': "foo$bar'
+
+expected_region_highlight=(
+  "3 6 $ZSH_HIGHLIGHT_STYLES[double-quoted-argument]" # "foo
+  "7 10 $ZSH_HIGHLIGHT_STYLES[dollar-double-quoted-argument]" # $bar
+)

highlighters/main/test-data/double-quoted3.zsh

@@ -0,0 +1,37 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2010-2011 zsh-syntax-highlighting contributors
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are permitted
+# provided that the following conditions are met:
+#
+#  * Redistributions of source code must retain the above copyright notice, this list of conditions
+#    and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright notice, this list of
+#    conditions and the following disclaimer in the documentation and/or other materials provided
+#    with the distribution.
+#  * Neither the name of the zsh-syntax-highlighting contributors nor the names of its contributors
+#    may be used to endorse or promote products derived from this software without specific prior
+#    written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# -------------------------------------------------------------------------------------------------
+# -*- mode: zsh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
+# vim: ft=zsh sw=2 ts=2 et
+# -------------------------------------------------------------------------------------------------
+
+BUFFER=': "$42foo"'
+
+expected_region_highlight=(
+  "3 3 $ZSH_HIGHLIGHT_STYLES[double-quoted-argument]" # "
+  "4 6 $ZSH_HIGHLIGHT_STYLES[dollar-double-quoted-argument]" # $42
+  "7 10 $ZSH_HIGHLIGHT_STYLES[double-quoted-argument]" # foo"
+)