deprecating _append_path and create _prepend_path

functions/_append_path.fish

 # Appends the path to the specified path list. If no list specified,
 #  defaults to $PATH
 function _append_path
+  set_color red
+  echo '_append_path function deprecated. Rename to _prepend_path.'
+  set_color normal
+
   set -l path PATH
 
   if test (echo $argv | wc -w) -eq 2

functions/_prepend_path.fish

+# Prepends the path to the specified path list. If no list specified, defaults to $PATH
+function _prepend_path
+  set -l path PATH
+
+  if test (echo $argv | wc -w) -eq 2
+    set path $argv[2]
+  end
+
+  if test -d $argv[1]
+    if not contains $argv[1] $$path
+      set $path $argv[1] $$path
+    end
+  end
+end

oh-my-fish.fish

@@ -6,16 +6,16 @@ function _fish_add_plugin
   set -l plugin $argv[1]
   set -l plugin_path "plugins/$plugin"
 
-  _append_path $fish_path/$plugin_path fish_function_path
-  _append_path $fish_custom/$plugin_path fish_function_path
+  _prepend_path $fish_path/$plugin_path fish_function_path
+  _prepend_path $fish_custom/$plugin_path fish_function_path
 end
 
 function _fish_add_completion
   set -l plugin $argv[1]
   set -l completion_path "plugins/$plugin/completions"
 
-  _append_path $fish_path/$completion_path fish_complete_path
-  _append_path $fish_custom/$completion_path fish_complete_path
+  _prepend_path $fish_path/$completion_path fish_complete_path
+  _prepend_path $fish_custom/$completion_path fish_complete_path
 end
 
 function _fish_source_plugin_load_file
@@ -32,8 +32,8 @@ function _fish_source_plugin_load_file
 end
 
 function _fish_load_theme
-  _append_path $fish_path/themes/$fish_theme fish_function_path
-  _append_path $fish_custom/themes/$fish_theme fish_function_path
+  _prepend_path $fish_path/themes/$fish_theme fish_function_path
+  _prepend_path $fish_custom/themes/$fish_theme fish_function_path
 end
 
 ###

plugins/android-sdk/android-sdk.load

 if test -n "$ANDROID_SDK_ROOT"
-  _append_path $ANDROID_SDK_ROOT/tools
-  _append_path $ANDROID_SDK_ROOT/platform-tools
+  _prepend_path $ANDROID_SDK_ROOT/tools
+  _prepend_path $ANDROID_SDK_ROOT/platform-tools
 else
-  _append_path /opt/android-sdk/tools
-  _append_path /opt/android-sdk/platform-tools
+  _prepend_path /opt/android-sdk/tools
+  _prepend_path /opt/android-sdk/platform-tools
 end

plugins/ccache/ccache.load

@@ -3,7 +3,7 @@
 set -gx USE_CCACHE 1
 
 if test -n "$CCACHE_ROOT"
-  _append_path $CCACHE_ROOT
+  _prepend_path $CCACHE_ROOT
 else
-  _append_path /usr/lib/ccache/bin
+  _prepend_path /usr/lib/ccache/bin
 end

plugins/gem/gem.load

 if test -n "$GEM_ROOT"
   set -gx GEM_HOME $GEM_ROOT
-  _append_path $GEM_ROOT/bin
+  _prepend_path $GEM_ROOT/bin
 end

plugins/gvm/gvm.load

 for gvm_path in (find $HOME/.gvm/*/current/bin -maxdepth 0)
-  _append_path $gvm_path
+  _prepend_path $gvm_path
 end

plugins/ndenv/ndenv.load

 if test -n "$NDENV_ROOT"
-  _append_path $NDENV_ROOT/bin
-  _append_path $NDENV_ROOT/shims
+  _prepend_path $NDENV_ROOT/bin
+  _prepend_path $NDENV_ROOT/shims
 else
-  _append_path $HOME/.ndenv/bin
-  _append_path $HOME/.ndenv/shims
+  _prepend_path $HOME/.ndenv/bin
+  _prepend_path $HOME/.ndenv/shims
 end

plugins/node/node.load

 ### Main program
-_append_path /usr/local/share/npm/bin
+_prepend_path /usr/local/share/npm/bin
 
 set PATH ./node_modules/.bin $PATH

plugins/nodenv/nodenv.load

 if test -n "$NODENV_ROOT"
-  _append_path $NODENV_ROOT/bin
+  _prepend_path $NODENV_ROOT/bin
 else
-  _append_path $HOME/.nodenv/bin
+  _prepend_path $HOME/.nodenv/bin
 end
 
 status --is-interactive; and source (nodenv init - | psub)

plugins/plenv/plenv.load

-_append_path $HOME/.plenv/bin
-_append_path $HOME/.plenv/shims
+_prepend_path $HOME/.plenv/bin
+_prepend_path $HOME/.plenv/shims

plugins/pyenv/pyenv.load

 if test -n "$PYENV_ROOT"
-  _append_path $PYENV_ROOT/bin
-  _append_path $PYENV_ROOT/shims
+  _prepend_path $PYENV_ROOT/bin
+  _prepend_path $PYENV_ROOT/shims
 else
-  _append_path $HOME/.pyenv/bin
-  _append_path $HOME/.pyenv/shims
+  _prepend_path $HOME/.pyenv/bin
+  _prepend_path $HOME/.pyenv/shims
 end

plugins/rbenv/rbenv.load

 if test -n "$RBENV_ROOT"
-  _append_path $RBENV_ROOT/bin
-  _append_path $RBENV_ROOT/shims
+  _prepend_path $RBENV_ROOT/bin
+  _prepend_path $RBENV_ROOT/shims
 else
-  _append_path $HOME/.rbenv/bin
-  _append_path $HOME/.rbenv/shims
+  _prepend_path $HOME/.rbenv/bin
+  _prepend_path $HOME/.rbenv/shims
 end