Fix zplug syntax

The space before "plugin" raises an error

README.md

@@ -23,7 +23,15 @@ Install
 Using the [Homebrew]( https://brew.sh ) package manager:
 
     brew install zsh-history-substring-search
-    echo 'source /usr/local/share/zsh-history-substring-search/zsh-history-substring-search.zsh' >> ~/.zshrc
+    echo 'source $(brew --prefix)/share/zsh-history-substring-search/zsh-history-substring-search.zsh' >> ~/.zshrc
+
+Using [Fig](https://fig.io):
+
+Fig adds apps, shortcuts, and autocomplete to your existing terminal.
+
+Install `zsh-history-substring-search` in just one click.
+
+<a href="https://fig.io/plugins/other/zsh-history-substring-search" target="_blank"><img src="https://fig.io/badges/install-with-fig.svg" /></a>
 
 Using [Oh-my-zsh](https://github.com/robbyrussell/oh-my-zsh):
 
@@ -33,24 +41,63 @@ Using [Oh-my-zsh](https://github.com/robbyrussell/oh-my-zsh):
 
 2. Activate the plugin in `~/.zshrc`:
 
-        plugins=( [plugins...] history-substring-search)
+        plugins=( [plugins...] zsh-history-substring-search)
 
-3. Source `~/.zshrc`  to take changes into account:
+3. Run `exec zsh`  to take changes into account:
 
-        source ~/.zshrc
+        exec zsh
+
+Using [zplug](https://github.com/zplug/zplug):
+
+1. Add this repo to `~/.zshrc`:
+
+        zplug "zsh-users/zsh-history-substring-search", as:plugin
+
+Using [antigen](https://github.com/zsh-users/antigen):
+
+1. Add the `antigen bundle` command just before `antigen apply`, like this:
+
+``` 
+antigen bundle zsh-users/zsh-history-substring-search
+antigen apply
+```
+ 
+2. Then, **after** `antigen apply`, add the key binding configurations, like this:
+ 
+```
+# zsh-history-substring-search configuration
+bindkey '^[[A' history-substring-search-up # or '\eOA'
+bindkey '^[[B' history-substring-search-down # or '\eOB'
+HISTORY_SUBSTRING_SEARCH_ENSURE_UNIQUE=1
+```
+
+Using [Zinit](https://github.com/zdharma-continuum/zinit):
+
+1. Use the `Oh-my-zsh` Zinit snippet in `~/.zshrc`:
+
+        zinit snippet OMZ::plugins/git/git.plugin.zsh
+
+2. Load the plugin in `~/.zshrc`:
+
+        zinit load 'zsh-users/zsh-history-substring-search'
+        zinit ice wait atload'_history_substring_search_config'
+
+3. Run `exec zsh` to take changes into account:
+
+        exec zsh
 
 Usage
 ------------------------------------------------------------------------------
 
 1.  Load this script into your interactive ZSH session:
 
-        % source zsh-history-substring-search.zsh
+        source zsh-history-substring-search.zsh
 
     If you want to use [zsh-syntax-highlighting][6] along with this script,
     then make sure that you load it *before* you load this script:
 
-        % source zsh-syntax-highlighting.zsh
-        % source zsh-history-substring-search.zsh
+        source zsh-syntax-highlighting.zsh
+        source zsh-history-substring-search.zsh
 
 2.  Bind keyboard shortcuts to this script's functions.
 
@@ -73,6 +120,10 @@ Usage
           bindkey "$terminfo[kcuu1]" history-substring-search-up
           bindkey "$terminfo[kcud1]" history-substring-search-down
 
+      Users have also observed that `[OA` and `[OB` are correct values, 
+      _even if_ these were not the observed values. If you are having trouble
+      with the observed values, give these a try.
+
       You might also want to bind the Control-P/N keys for use in EMACS mode:
 
           bindkey -M emacs '^P' history-substring-search-up
@@ -115,7 +166,7 @@ Configuration
 ------------------------------------------------------------------------------
 
 This script defines the following global variables. You may override their
-default values only after having loaded this script into your ZSH session.
+default values.
 
 * `HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_FOUND` is a global variable that defines
   how the query should be highlighted inside a matching command. Its default
@@ -141,6 +192,12 @@ default values only after having loaded this script into your ZSH session.
   value, causes this script to perform a fuzzy search by words, matching in
   given order e.g. `ab c` will match `*ab*c*`
 
+* `HISTORY_SUBSTRING_SEARCH_PREFIXED` is a global variable that defines how
+  the command history will be searched for your query. If set to a non-empty
+  value, your query will be matched against the start of each history entry.
+  For example, if this variable is empty, `ls` will match `ls -l` and `echo
+  ls`; if it is non-empty, `ls` will only match `ls -l`.
+
 * `HISTORY_SUBSTRING_SEARCH_ENSURE_UNIQUE` is a global variable that defines
   whether all search results returned are _unique_. If set to a non-empty
   value, then only unique search results are presented. This behaviour is off
@@ -155,6 +212,9 @@ default values only after having loaded this script into your ZSH session.
   receive globally unique search results only once, then use this
   configuration variable, or use `setopt HIST_IGNORE_ALL_DUPS`.
 
+* `HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_TIMEOUT` is a global variable that
+  defines a timeout in seconds for clearing the search highlight.
+
 
 History
 ------------------------------------------------------------------------------

zsh-history-substring-search.zsh

@@ -43,11 +43,12 @@
 # declare global configuration variables
 #-----------------------------------------------------------------------------
 
-typeset -g HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_FOUND='bg=magenta,fg=white,bold'
-typeset -g HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_NOT_FOUND='bg=red,fg=white,bold'
-typeset -g HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS='i'
-typeset -g HISTORY_SUBSTRING_SEARCH_ENSURE_UNIQUE=''
-typeset -g HISTORY_SUBSTRING_SEARCH_FUZZY=''
+: ${HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_FOUND='bg=magenta,fg=white,bold'}
+: ${HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_NOT_FOUND='bg=red,fg=white,bold'}
+: ${HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS='i'}
+: ${HISTORY_SUBSTRING_SEARCH_ENSURE_UNIQUE=''}
+: ${HISTORY_SUBSTRING_SEARCH_FUZZY=''}
+: ${HISTORY_SUBSTRING_SEARCH_PREFIXED=''}
 
 #-----------------------------------------------------------------------------
 # declare internal global variables
@@ -64,6 +65,7 @@ typeset -g -i _history_substring_search_raw_match_index
 typeset -g -a _history_substring_search_matches
 typeset -g -i _history_substring_search_match_index
 typeset -g -A _history_substring_search_unique_filter
+typeset -g -i _history_substring_search_zsh_5_9
 
 #-----------------------------------------------------------------------------
 # the main ZLE widgets
@@ -97,6 +99,11 @@ zle -N history-substring-search-down
 #-----------------------------------------------------------------------------
 
 zmodload -F zsh/parameter
+autoload -Uz is-at-least
+
+if is-at-least 5.9 $ZSH_VERSION; then
+  _history_substring_search_zsh_5_9=1
+fi
 
 #
 # We have to "override" some keys and widgets if the
@@ -117,80 +124,125 @@ if [[ $+functions[_zsh_highlight] -eq 0 ]]; then
   }
 
   #
-  # The following snippet was taken from the zsh-syntax-highlighting project:
+  # Check if $1 denotes the name of a callable function, i.e. it is fully
+  # defined or it is marked for autoloading and autoloading it at the first
+  # call to it will succeed. In particular, if $1 has been marked for
+  # autoloading but is not available in $fpath, then it will return 1 (false).
   #
-  # https://github.com/zsh-users/zsh-syntax-highlighting/blob/56b134f5d62ae3d4e66c7f52bd0cc2595f9b305b/zsh-syntax-highlighting.zsh#L126-161
+  # This is based on the zsh-syntax-highlighting plugin.
   #
-  # Copyright (c) 2010-2011 zsh-syntax-highlighting contributors
-  # All rights reserved.
+  _history-substring-search-function-callable() {
+    if (( ${+functions[$1]} )) && ! [[ "$functions[$1]" == *"builtin autoload -X"* ]]; then
+      return 0 # already fully loaded
+    else
+      # "$1" is either an autoload stub, or not a function at all.
+      # We expect 'autoload +X' to return non-zero if it fails to fully load
+      # the function.
+      ( autoload -U +X -- "$1" 2>/dev/null )
+      return $?
+    fi
+  }
+
   #
-  # Redistribution and use in source and binary forms, with or without
-  # modification, are permitted provided that the following conditions are
-  # met:
+  # The zsh-syntax-highlighting plugin uses zle-line-pre-redraw hook instead
+  # of the legacy "bind all widgets" if 1) zsh has the memo= feature (added in
+  # version 5.9) and 2) add-zle-hook-widget is available.
   #
-  #  * 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.
-  #
-  #--------------8<-------------------8<-------------------8<-----------------
-  # Rebind all ZLE widgets to make them invoke _zsh_highlights.
-  _zsh_highlight_bind_widgets()
-  {
-    # Load ZSH module zsh/zleparameter, needed to override user defined widgets.
-    zmodload zsh/zleparameter 2>/dev/null || {
-      echo 'zsh-syntax-highlighting: failed loading zsh/zleparameter.' >&2
-      return 1
+  if [[ $_history_substring_search_zsh_5_9 -eq 1 ]] && _history-substring-search-function-callable add-zle-hook-widget; then
+    #
+    # The following code is based on the zsh-syntax-highlighting plugin.
+    #
+    autoload -U add-zle-hook-widget
+
+    _history-substring-search-zle-line-finish() {
+      #
+      # Reset $WIDGET since the 'main' highlighter depends on it.
+      #
+      # Since $WIDGET is declared by zle as read-only in this function's scope,
+      # a nested function is required in order to shadow its built-in value;
+      # see "User-defined widgets" in zshall.
+      #
+      () {
+        local -h -r WIDGET=zle-line-finish
+        _zsh_highlight
+      }
     }
 
-    # Override ZLE widgets to make them invoke _zsh_highlight.
-    local cur_widget
-    for cur_widget in ${${(f)"$(builtin zle -la)"}:#(.*|_*|orig-*|run-help|which-command|beep|yank*)}; do
-      case $widgets[$cur_widget] in
+    _history-substring-search-zle-line-pre-redraw() {
+      #
+      # If the zsh-syntax-highlighting plugin has been loaded (after our plugin
+      # plugin, otherwise this hook wouldn't be called), remove our hooks.
+      #
+      if [[ $+ZSH_HIGHLIGHT_VERSION -eq 1 ]]; then
+        autoload -U add-zle-hook-widget
+        add-zle-hook-widget -d zle-line-pre-redraw _history-substring-search-zle-line-pre-redraw
+        add-zle-hook-widget -d zle-line-finish _history-substring-search-zle-line-finish
+        return 0
+      fi
+      #
+      # Set $? to 0 for _zsh_highlight.  Without this, subsequent
+      # zle-line-pre-redraw hooks won't run, since add-zle-hook-widget happens to
+      # call us with $? == 1 in the common case.
+      #
+      true && _zsh_highlight "$@"
+    }
 
-        # Already rebound event: do nothing.
-        user:$cur_widget|user:_zsh_highlight_widget_*);;
+    if [[ -o zle ]]; then
+      add-zle-hook-widget zle-line-pre-redraw _history-substring-search-zle-line-pre-redraw
+      add-zle-hook-widget zle-line-finish _history-substring-search-zle-line-finish
+    fi
+  else
+    #
+    # The following snippet was taken from the zsh-syntax-highlighting project:
+    # https://github.com/zsh-users/zsh-syntax-highlighting/blob/56b134f5d62ae3d4e66c7f52bd0cc2595f9b305b/zsh-syntax-highlighting.zsh#L126-161
+    #
+    # SPDX-SnippetBegin
+    # SPDX-License-Identifier: BSD-3-Clause
+    # SPDX-SnippetCopyrightText: 2010-2011 zsh-syntax-highlighting contributors
+    #--------------8<-------------------8<-------------------8<-----------------
+    # Rebind all ZLE widgets to make them invoke _zsh_highlights.
+    _zsh_highlight_bind_widgets()
+    {
+      # Load ZSH module zsh/zleparameter, needed to override user defined widgets.
+      zmodload zsh/zleparameter 2>/dev/null || {
+        echo 'zsh-syntax-highlighting: failed loading zsh/zleparameter.' >&2
+        return 1
+      }
 
-        # User defined widget: override and rebind old one with prefix "orig-".
-        user:*) eval "zle -N orig-$cur_widget ${widgets[$cur_widget]#*:}; \
-                      _zsh_highlight_widget_$cur_widget() { builtin zle orig-$cur_widget -- \"\$@\" && _zsh_highlight }; \
-                      zle -N $cur_widget _zsh_highlight_widget_$cur_widget";;
+      # Override ZLE widgets to make them invoke _zsh_highlight.
+      local cur_widget
+      for cur_widget in ${${(f)"$(builtin zle -la)"}:#(.*|_*|orig-*|run-help|which-command|beep|yank*)}; do
+        case $widgets[$cur_widget] in
 
-        # Completion widget: override and rebind old one with prefix "orig-".
-        completion:*) eval "zle -C orig-$cur_widget ${${widgets[$cur_widget]#*:}/:/ }; \
-                            _zsh_highlight_widget_$cur_widget() { builtin zle orig-$cur_widget -- \"\$@\" && _zsh_highlight }; \
-                            zle -N $cur_widget _zsh_highlight_widget_$cur_widget";;
+          # Already rebound event: do nothing.
+          user:$cur_widget|user:_zsh_highlight_widget_*);;
 
-        # Builtin widget: override and make it call the builtin ".widget".
-        builtin) eval "_zsh_highlight_widget_$cur_widget() { builtin zle .$cur_widget -- \"\$@\" && _zsh_highlight }; \
-                       zle -N $cur_widget _zsh_highlight_widget_$cur_widget";;
+          # User defined widget: override and rebind old one with prefix "orig-".
+          user:*) eval "zle -N orig-$cur_widget ${widgets[$cur_widget]#*:}; \
+                        _zsh_highlight_widget_$cur_widget() { builtin zle orig-$cur_widget -- \"\$@\" && _zsh_highlight }; \
+                        zle -N $cur_widget _zsh_highlight_widget_$cur_widget";;
 
-        # Default: unhandled case.
-        *) echo "zsh-syntax-highlighting: unhandled ZLE widget '$cur_widget'" >&2 ;;
-      esac
-    done
-  }
-  #-------------->8------------------->8------------------->8-----------------
+          # Completion widget: override and rebind old one with prefix "orig-".
+          completion:*) eval "zle -C orig-$cur_widget ${${widgets[$cur_widget]#*:}/:/ }; \
+                              _zsh_highlight_widget_$cur_widget() { builtin zle orig-$cur_widget -- \"\$@\" && _zsh_highlight }; \
+                              zle -N $cur_widget _zsh_highlight_widget_$cur_widget";;
 
-  _zsh_highlight_bind_widgets
+          # Builtin widget: override and make it call the builtin ".widget".
+          builtin) eval "_zsh_highlight_widget_$cur_widget() { builtin zle .$cur_widget -- \"\$@\" && _zsh_highlight }; \
+                         zle -N $cur_widget _zsh_highlight_widget_$cur_widget";;
+
+          # Default: unhandled case.
+          *) echo "zsh-syntax-highlighting: unhandled ZLE widget '$cur_widget'" >&2 ;;
+        esac
+      done
+    }
+    #-------------->8------------------->8------------------->8-----------------
+    # SPDX-SnippetEnd
+
+    _zsh_highlight_bind_widgets
+  fi
+
+  unfunction _history-substring-search-function-callable
 fi
 
 _history-substring-search-begin() {
@@ -246,7 +298,14 @@ _history-substring-search-begin() {
     # Escape and join query parts with wildcard character '*' as seperator
     # `(j:CHAR:)` join array to string with CHAR as seperator
     #
-    local search_pattern="*${(j:*:)_history_substring_search_query_parts[@]//(#m)[\][()|\\*?#<>~^]/\\$MATCH}*"
+    local search_pattern="${(j:*:)_history_substring_search_query_parts[@]//(#m)[\][()|\\*?#<>~^]/\\$MATCH}*"
+
+    #
+    # Support anchoring history search to the beginning of the command
+    #
+    if [[ -z $HISTORY_SUBSTRING_SEARCH_PREFIXED ]]; then
+      search_pattern="*${search_pattern}"
+    fi
 
     #
     # Find all occurrences of the search pattern in the history file.
@@ -304,12 +363,21 @@ _history-substring-search-begin() {
 _history-substring-search-end() {
   setopt localoptions extendedglob
 
+  local highlight_memo=
   _history_substring_search_result=$BUFFER
 
+  if [[ $_history_substring_search_zsh_5_9 -eq 1 ]]; then
+    highlight_memo='memo=history-substring-search'
+  fi
+
   # the search was successful so display the result properly by clearing away
   # existing highlights and moving the cursor to the end of the result buffer
   if [[ $_history_substring_search_refresh_display -eq 1 ]]; then
-    region_highlight=()
+    if [[ -n $highlight_memo ]]; then
+      region_highlight=( "${(@)region_highlight:#*${highlight_memo}*}" )
+    else
+      region_highlight=()
+    fi
     CURSOR=${#BUFFER}
   fi
 
@@ -329,14 +397,33 @@ _history-substring-search-end() {
       if [[ $query_part_match_index -le ${#BUFFER:$highlight_start_index} ]]; then
         highlight_start_index=$(( $highlight_start_index + $query_part_match_index ))
         highlight_end_index=$(( $highlight_start_index + ${#query_part} ))
-        region_highlight+=("$(($highlight_start_index - 1)) $(($highlight_end_index - 1)) $_history_substring_search_query_highlight")
+        region_highlight+=(
+          "$(($highlight_start_index - 1)) $(($highlight_end_index - 1)) ${_history_substring_search_query_highlight}${highlight_memo:+,$highlight_memo}"
+        )
       fi
     done
   fi
 
   # For debugging purposes:
   # zle -R "mn: "$_history_substring_search_match_index" m#: "${#_history_substring_search_matches}
-  # read -k -t 200 && zle -U $REPLY
+  # read -k -t 200 && zle -U -- "$REPLY"
+
+  #
+  # When this function returns, z-sy-h runs its line-pre-redraw hook. It has no
+  # logic for determining highlight priority, when two different memo= marked
+  # region highlights overlap; instead, it always prioritises itself. Below is
+  # a workaround for dealing with it.
+  #
+  if [[ $_history_substring_search_zsh_5_9 -eq 1 ]]; then
+    zle -R
+    #
+    # After line redraw with desired highlight, wait for timeout or user input
+    # before removing search highlight and exiting. This ensures no highlights
+    # are left lingering after search is finished.
+    #
+    read -k -t ${HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_TIMEOUT:-1} && zle -U -- "$REPLY"
+    region_highlight=( "${(@)region_highlight:#*${highlight_memo}*}" )
+  fi
 
   # Exit successfully from the history-substring-search-* widgets.
   return 0