Refactoring: make logic more fit for rearrangement

With functions, we have more leeway in what to call

libexec/pyenv-init

@@ -43,7 +43,29 @@ fi
 
 root="${0%/*}/.."
 
-if [ -z "$print" ]; then
+function main() {
+  case "$mode" in
+  "help")
+    help_
+    exit 1
+    ;;
+  "path")
+    print_path
+    exit 0
+    ;;
+  "print")
+    init_dirs
+    print_env
+    print_completion
+    print_shell_function
+    exit 0
+    ;;
+  esac
+  # should never get here
+  exit 2
+}
+
+function help_() {
   case "$shell" in
   bash )
     if [ -f "${HOME}/.bashrc" ] && [ ! -f "${HOME}/.bash_profile" ]; then
@@ -79,12 +101,13 @@ if [ -z "$print" ]; then
     esac
     echo
   } >&2
+}
 
-  exit 1
-fi
-
+function init_dirs() {
   mkdir -p "${PYENV_ROOT}/"{shims,versions}
+}
 
+function print_env() {
   case "$shell" in
   fish )
     echo "set -gx PATH '${PYENV_ROOT}/shims' \$PATH"
@@ -95,7 +118,9 @@ fish )
     echo "export PYENV_SHELL=$shell"
     ;;
   esac
+}
 
+function print_completion() {
   completion="${root}/completions/pyenv.${shell}"
   if [ -r "$completion" ]; then
     echo "source '$completion'"
@@ -104,7 +129,9 @@ fi
   if [ -z "$no_rehash" ]; then
     echo 'command pyenv rehash 2>/dev/null'
   fi
+}
 
+function print_shell_function() {
   commands=(`pyenv-commands --sh`)
   case "$shell" in
   fish )
@@ -146,10 +173,15 @@ cat <<EOS
 
   case "\$command" in
   ${commands[*]})
-    eval "\$(pyenv "sh-\$command" "\$@")";;
+    eval "\$(pyenv "sh-\$command" "\$@")"
+    ;;
   *)
-    command pyenv "\$command" "\$@";;
+    command pyenv "\$command" "\$@"
+    ;;
   esac
 }
 EOS
   fi
+}
+
+main