Improve brew* rules import time

thefuck/rules/brew_install.py

@@ -1,38 +1,38 @@
 import os
 import re
-from subprocess import check_output
-from thefuck.utils import get_closest, replace_argument
+from thefuck.utils import get_closest, replace_argument, which
+from thefuck.specific.brew import get_brew_path_prefix
 
-# Formulars are base on each local system's status
 
-brew_formulas = []
-try:
-    brew_path_prefix = check_output(['brew', '--prefix'],
-                                    universal_newlines=True).strip()
-    brew_formula_path = brew_path_prefix + '/Library/Formula'
+enabled_by_default = bool(which('brew'))
 
-    for file_name in os.listdir(brew_formula_path):
-        if file_name.endswith('.rb'):
-            brew_formulas.append(file_name.replace('.rb', ''))
-except:
-    pass
+
+def _get_formulas():
+    # Formulas are based on each local system's status
+    try:
+        brew_path_prefix = get_brew_path_prefix()
+        brew_formula_path = brew_path_prefix + '/Library/Formula'
+
+        for file_name in os.listdir(brew_formula_path):
+            if file_name.endswith('.rb'):
+                yield file_name[:-3]
+    except:
+        pass
 
 
 def _get_similar_formula(formula_name):
-    return get_closest(formula_name, brew_formulas, 1, 0.85)
+    return get_closest(formula_name, _get_formulas(), 1, 0.85)
 
 
 def match(command, settings):
     is_proper_command = ('brew install' in command.script and
                          'No available formula' in command.stderr)
 
-    has_possible_formulas = False
     if is_proper_command:
         formula = re.findall(r'Error: No available formula for ([a-z]+)',
                              command.stderr)[0]
-        has_possible_formulas = bool(_get_similar_formula(formula))
-
-    return has_possible_formulas
+        return bool(_get_similar_formula(formula))
+    return False
 
 
 def get_new_command(command, settings):