Make Settings class more flexible, less brittle

I hadn't touched this class for about 4 years, and this morning had to
add another setting to it in order to fix a bug (see commit
2861dc1). With a more flexible design, I could have left it
untouched.

This commit implements that design, teaching the settings class to
fully mediate between the caller who wants to save/restore some
settings, and Vim. It records the settings that are to be changed, makes
the changes, and can restore the settings by "replaying" the recorded
settings.

Signed-off-by: Wincent Colaiuta <win@wincent.com>

ruby/command-t/match_window.rb

@@ -49,16 +49,16 @@ def initialize options = {}
 
       # global settings (must manually save and restore)
       @settings = Settings.new
-      ::VIM::set_option 'timeout'         # ensure mappings timeout
-      ::VIM::set_option 'timeoutlen=0'    # respond immediately to mappings
-      ::VIM::set_option 'nohlsearch'      # don't highlight search strings
-      ::VIM::set_option 'noinsertmode'    # don't make Insert mode the default
-      ::VIM::set_option 'noshowcmd'       # don't show command info on last line
-      ::VIM::set_option 'report=9999'     # don't show "X lines changed" reports
-      ::VIM::set_option 'sidescroll=0'    # don't sidescroll in jumps
-      ::VIM::set_option 'sidescrolloff=0' # don't sidescroll automatically
-      ::VIM::set_option 'noequalalways'   # don't auto-balance window sizes
-      ::VIM::set_option "updatetime=#{options[:debounce_interval]}"
+      @settings.set 'timeout', true        # ensure mappings timeout
+      @settings.set 'hlsearch', false      # don't highlight search strings
+      @settings.set 'insertmode', false    # don't make Insert mode the default
+      @settings.set 'showcmd', false       # don't show command info on last line
+      @settings.set 'equalalways', false   # don't auto-balance window sizes
+      @settings.set 'timeoutlen', 0        # respond immediately to mappings
+      @settings.set 'report', 9999         # don't show "X lines changed" reports
+      @settings.set 'sidescroll', 0        # don't sidescroll in jumps
+      @settings.set 'sidescrolloff', 0     # don't sidescroll automatically
+      @settings.set 'updatetime', options[:debounce_interval]
 
       # show match window
       split_location = options[:match_window_at_top] ? 'topleft' : 'botright'

ruby/command-t/settings.rb

@@ -25,50 +25,46 @@ module CommandT
   # Convenience class for saving and restoring global settings.
   class Settings
     def initialize
-      save
+      @settings = []
     end
 
-    def save
-      @timeoutlen     = get_number 'timeoutlen'
-      @report         = get_number 'report'
-      @sidescroll     = get_number 'sidescroll'
-      @sidescrolloff  = get_number 'sidescrolloff'
-      @updatetime     = get_number 'updatetime'
-      @timeout        = get_bool 'timeout'
-      @equalalways    = get_bool 'equalalways'
-      @hlsearch       = get_bool 'hlsearch'
-      @insertmode     = get_bool 'insertmode'
-      @showcmd        = get_bool 'showcmd'
+    def set(setting, value)
+      case value
+      when TrueClass, FalseClass
+        @settings.push([setting, get_bool(setting)])
+        set_bool setting, value
+      when Numeric
+        @settings.push([setting, get_number(setting)])
+        set_number setting, value
+      end
     end
 
     def restore
-      set_number 'timeoutlen', @timeoutlen
-      set_number 'report', @report
-      set_number 'sidescroll', @sidescroll
-      set_number 'sidescrolloff', @sidescrolloff
-      set_number 'updatetime', @updatetime
-      set_bool 'timeout', @timeout
-      set_bool 'equalalways', @equalalways
-      set_bool 'hlsearch', @hlsearch
-      set_bool 'insertmode', @insertmode
-      set_bool 'showcmd', @showcmd
+      @settings.each do |setting, value|
+        case value
+        when TrueClass, FalseClass
+          set_bool setting, value
+        when Numeric
+          set_number setting, value
+        end
+      end
     end
 
   private
 
-    def get_number setting
+    def get_number(setting)
       ::VIM::evaluate("&#{setting}").to_i
     end
 
-    def get_bool setting
+    def get_bool(setting)
       ::VIM::evaluate("&#{setting}").to_i == 1
     end
 
-    def set_number setting, value
+    def set_number(setting, value)
       ::VIM::set_option "#{setting}=#{value}"
     end
 
-    def set_bool setting, value
+    def set_bool(setting, value)
       if value
         ::VIM::set_option setting
       else