prompt: update sorin prompt async usage to be closer to pure

modules/prompt/functions/prompt_sorin_setup

@@ -32,7 +32,9 @@
 # Load dependencies.
 pmodload 'helper'
 
-function prompt_sorin_git_info {
+function prompt_sorin_async_callback {
+  case $1 in
+    prompt_sorin_async_git)
       # We can safely split on ':' because it isn't allowed in ref names.
       IFS=':' read _git_target _git_post_target <<<"$3"
 
@@ -51,6 +53,8 @@ function prompt_sorin_git_info {
         _prompt_sorin_git="${_git_target}${_git_post_target}"
         zle && zle reset-prompt
       fi
+      ;;
+  esac
 }
 
 function prompt_sorin_async_git {
@@ -61,6 +65,22 @@ function prompt_sorin_async_git {
   fi
 }
 
+function prompt_sorin_async_tasks {
+  # Initialize async worker. This needs to be done here and not in
+  # prompt_sorin_setup so the git formatting can be overridden by other prompts.
+  if (( !${prompt_prezto_async_init:-0} )); then
+    async_start_worker prompt_sorin -n
+    async_register_callback prompt_sorin prompt_sorin_async_callback
+    typeset -g prompt_prezto_async_init=1
+  fi
+
+  # Kill the old process of slow commands if it is still running.
+  async_flush_jobs async_sorin_git
+
+  # Compute slow commands in the background.
+  async_job async_sorin_git prompt_sorin_async_git "$PWD"
+}
+
 function prompt_sorin_precmd {
   setopt LOCAL_OPTIONS
   unsetopt XTRACE KSH_ARRAYS
@@ -68,9 +88,6 @@ function prompt_sorin_precmd {
   # Format PWD.
   _prompt_sorin_pwd=$(prompt-pwd)
 
-  # Kill the old process of slow commands if it is still running.
-  async_flush_jobs async_sorin_git
-
   # Handle updating git data. We also clear the git prompt data if we're in a
   # different git root now.
   if (( $+functions[git-dir] )); then
@@ -81,14 +98,12 @@ function prompt_sorin_precmd {
     fi
   fi
 
-  
   # Run python info (this should be fast and not require any async)
   if (( $+functions[python-info] )); then
     python-info
   fi
 
-  # Compute slow commands in the background.
-  async_job async_sorin_git prompt_sorin_async_git "$PWD"
+  prompt_sorin_async_tasks
 }
 
 function prompt_sorin_setup {
@@ -139,8 +154,6 @@ function prompt_sorin_setup {
   zstyle ':prezto:module:python:info:virtualenv' format '%f%F{3}(%v)%F{7} '
 
   # Get the async worker set up
-  async_start_worker async_sorin_git -n
-  async_register_callback async_sorin_git prompt_sorin_git_info
   _sorin_cur_git_root=''
 
   _prompt_sorin_git=''