move tick-counting into COPILOT

4 files changed, 41 insertions, 48 deletions

diff --git a/alv/copilot.moon b/alv/copilot.moon
index 9d573c0..d4612c8 100644
--- a/alv/copilot.moon
+++ b/alv/copilot.moon
@@ -13,6 +13,8 @@ spit = (file, str) ->
   file\write str
   file\close!
 
+export COPILOT
+
 class Copilot
 --- static functions
 -- @section static
@@ -21,9 +23,18 @@ class Copilot
   -- @classmethod
   -- @tparam string file name/path of the alive file to watch and execute
   new: (file) =>
+    @T = 0
     @registry = Registry!
     @open file if file
 
+--- members
+-- @section members
+
+  --- current tick
+  -- @tfield number T
+
+  --- change the running script.
+  -- @tparam string file
   open: (file) =>
     mode = lfs.attributes file, 'mode'
     if mode != 'file'
@@ -32,37 +43,29 @@ class Copilot
     @last_modification = 0
     @file = file
 
---- members
--- @section members
-
   --- poll for changes and tick.
   tick: =>
-    return unless @file
+    assert not COPILOT, "another Copilot is already running!"
+    COPILOT = @
+    @T += 1
 
+    return unless @file
     @poll!
 
     if @root
       L\set_time 'run'
-      @registry\begin_tick!
       ok, error = Error.try "updating", ->
         @root\tick_io!
         @root\tick!
       if not ok
         L\print error
-      @registry\end_tick!
 
-  eval: =>
-    @registry\begin_eval!
-    ok, root, ast = Error.try "running '#{@file}'", loadfile, @file
-    if not ok
-      L\print root
-      @registry\rollback_eval!
-      return
-
-    @registry\end_eval!
-    @root = root
-    spit @file, ast\stringify!
+    COPILOT = nil
 
+  --- poll all loaded modules for changes.
+  --
+  -- Call `eval` if there are any, and write changed and newly added modules
+  -- back to disk.
   poll: =>
     { :mode, :modification } = (lfs.attributes @file) or {}
     if mode != 'file'
@@ -74,6 +77,19 @@ class Copilot
       @eval!
       @last_modification = os.time!
 
+  --- perform an eval-cycle.
+  eval: =>
+    @registry\begin_eval!
+    ok, root, ast = Error.try "running '#{@file}'", loadfile, @file
+    if not ok
+      L\print root
+      @registry\rollback_eval!
+      return
+
+    @registry\end_eval!
+    @root = root
+    spit @file, ast\stringify!
+
 {
   :Copilot
 }
diff --git a/alv/registry.moon b/alv/registry.moon
index 21f57aa..4bd03f6 100644
--- a/alv/registry.moon
+++ b/alv/registry.moon
@@ -39,13 +39,12 @@ class Registry
 
   --- begin an evaluation cycle.
   --
-  -- Begin an evaltime cycle (and tick).
   -- Set the active Registry and clear out pending registrations.
   --
   -- All calls go `begin_eval` must be matched with either a call to
   -- `end_eval` or `rollback_eval`.
   begin_eval: =>
-    @begin_tick!
+    @grab!
     @map, @pending = {}, {}
 
   --- end an evaluation cycle.
@@ -67,31 +66,14 @@ class Registry
       @map[tag\index!] = expr
 
     @last_map = @map
-    @end_tick!
+    @release!
 
   --- abort an evaluation cycle.
   --
   -- Unset the active Registry.
   rollback_eval: =>
-    @end_tick!
-
-  --- begin a run cycle.
-  --
-  -- Increment the tick index and set the active Registry.
-  begin_tick: =>
-    @grab!
-    @next_tick!
-
-  --- end a run cycle.
-  --
-  -- Unset the active Registry.
-  end_tick: =>
     @release!
 
-  --- manually increment the tick index (for testing).
-  next_tick: =>
-    @tick += 1
-
   --- set the active Registry.
   grab: =>
     assert not @prev, "already have a previous registry? #{@prev}"
@@ -109,7 +91,6 @@ class Registry
   -- @classmethod
   new: =>
     @last_map, @map = {}, {}
-    @tick = 0
 
   --- get the active Registry.
   --
@@ -121,10 +102,6 @@ class Registry
 class SimpleRegistry extends Registry
   new: =>
     @cnt = 1
-    @tick = 0
-
-  next_tick: =>
-    @tick += 1
 
   init: (tag, expr) =>
     tag\set @cnt
diff --git a/alv/stream/event.moon b/alv/stream/event.moon
index 97570a2..16716be 100644
--- a/alv/stream/event.moon
+++ b/alv/stream/event.moon
@@ -5,7 +5,7 @@
 import Stream from require 'alv.stream.base'
 import Result from require 'alv.result'
 import Error from require 'alv.error'
-import scope, base, registry from require 'alv.cycle'
+import scope, base from require 'alv.cycle'
 
 class EventStream extends Stream
 --- members
@@ -14,7 +14,7 @@ class EventStream extends Stream
   --- return whether this stream was changed in the current tick.
   --
   -- @treturn bool
-  dirty: => @updated == registry.Registry.active!.tick
+  dirty: => @updated == COPILOT.T
 
   --- push an event value into the stream.
   --
@@ -25,7 +25,7 @@ class EventStream extends Stream
     if not @dirty!
       @events = {}
 
-    @updated = registry.Registry.active!.tick
+    @updated = COPILOT.T
     table.insert @events, event
 
   --- get the sequence of current events (if any).
diff --git a/alv/stream/value.moon b/alv/stream/value.moon
index 213a26c..98720c9 100644
--- a/alv/stream/value.moon
+++ b/alv/stream/value.moon
@@ -7,7 +7,7 @@
 import Stream from require 'alv.stream.base'
 import Result from require 'alv.result'
 import Error from require 'alv.error'
-import scope, base, registry from require 'alv.cycle'
+import scope, base from require 'alv.cycle'
 
 ancestor = (klass) ->
   assert klass, "cant find the ancestor of nil"
@@ -22,12 +22,12 @@ class ValueStream extends Stream
   --- return whether this stream was changed in the current tick.
   --
   -- @treturn bool
-  dirty: => @updated == registry.Registry.active!.tick
+  dirty: => @updated == COPILOT.T
 
   --- update this stream's value.
   --
   -- Marks this stream as dirty for the remainder of the current tick.
-  set: (@value) => @updated = registry.Registry.active!.tick
+  set: (@value) => @updated = COPILOT.T
 
   --- unwrap to the Lua type.
   --