fix registry/module bugs

- registry not released when errors occur
  - registry is no longer grabbed, problem solved ;)
- ops not reliably destroyed
  - only destroy ops who were *not* forked

6 files changed, 18 insertions, 42 deletions

diff --git a/alv/base/builtin.moon b/alv/base/builtin.moon
index b9e7e55..f675207 100644
--- a/alv/base/builtin.moon
+++ b/alv/base/builtin.moon
@@ -83,7 +83,6 @@ class Builtin
     if compatible
       builtin\setup last
     else
-      last\destroy! if last
       builtin\setup nil
 
     builtin\eval scope, cell\tail!
diff --git a/alv/copilot.moon b/alv/copilot.moon
index 2b97d48..7ef2134 100644
--- a/alv/copilot.moon
+++ b/alv/copilot.moon
@@ -20,6 +20,7 @@ class Copilot
   -- @tparam string file name/path of the alive file to watch and execute
   new: (file) =>
     @T = 0
+    @last_modification = 0
     @last_modules = {}
     @open file if file
 
@@ -54,8 +55,11 @@ class Copilot
           last = @active_module
           prefix = @active_module.file\match('(.*)/[^/]*$') .. '/' or ''
           mod = @last_modules[name] or Module "#{prefix}#{name}.alv"
+          L\trace "entering module #{mod}"
+          @modules[name] = mod
           @active_module = mod
           ok, err = pcall mod\eval
+          L\trace "returning to module #{mod}"
           @active_module = last
           if ok
             mod.root
@@ -90,11 +94,12 @@ class Copilot
   poll: =>
     dirty = {}
     for name, mod in pairs @last_modules
-      if mod\poll!
+      if mod\poll! > @last_modification
         table.insert dirty, mod
 
     return if #dirty == 0
 
+    @last_modification = os.time!
     L\set_time 'eval'
     L\print "changes to files: #{table.concat [m.file for m in *dirty], ', '}"
 
@@ -115,6 +120,7 @@ class Copilot
     for name, mod in pairs @modules
       mod\finish!
 
+    @last_modification = os.time!
     @last_modules, @modules = @modules, nil
 
 {
diff --git a/alv/invoke.moon b/alv/invoke.moon
index fba6485..439af49 100644
--- a/alv/invoke.moon
+++ b/alv/invoke.moon
@@ -32,6 +32,7 @@ class op_invoke extends Builtin
   setup: (prev) =>
     if prev
       @op = prev.op\fork!
+      prev.forked = COPILOT.T
     else
       def = @head\unwrap 'opdef', "cant op-invoke #{@head}"
       @op = def!
@@ -39,7 +40,9 @@ class op_invoke extends Builtin
   --- `Builtin:destroy` implementation.
   --
   -- calls `op`:@{Op:destroy|destroy}.
-  destroy: => @op\destroy!
+  destroy: =>
+    if @forked ~= COPILOT.T
+      @op\destroy!
 
   --- perform an `Op` invocation.
   --
diff --git a/alv/module.moon b/alv/module.moon
index 356bcf5..8fc3ba7 100644
--- a/alv/module.moon
+++ b/alv/module.moon
@@ -26,7 +26,6 @@ class Module
   -- @classmethod
   new: (@file) =>
     @registry = Registry!
-    @last_modification = 0
 
 --- members
 -- @section members
@@ -36,23 +35,19 @@ class Module
   poll: =>
     { :mode, :modification } = (lfs.attributes @file) or {}
     assert mode == 'file', Error 'io', "not a file: '#{file}'"
-
-    if @last_modification < modification
-      true
+    modification
 
   --- start an evaluation cycle.
   --
   -- If the module has already been evaluated this tick, this is a noop.
   -- Otherwise, register the module with the `Copilot`. Updates `root`.
   eval: =>
-    @last_modification = os.time!
+    @registry\begin_eval!
     @ast = Error.wrap "parsing '#{@file}'", -> program\match slurp @file
     assert @ast, Error 'syntax', "failed to parse"
 
     scope = Scope builtin
-    @registry\begin_eval!
     @root = Error.wrap "evaluating '#{@file}'", @ast\eval, scope, @registry
-    @registry\release!
 
   --- rollback the last evaluation cycle.
   rollback: => @registry\rollback_eval!
diff --git a/alv/registry.moon b/alv/registry.moon
index d4dcccc..1b24e9a 100644
--- a/alv/registry.moon
+++ b/alv/registry.moon
@@ -40,19 +40,15 @@ class Registry
 
   --- begin an evaluation cycle.
   --
-  -- 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: =>
-    @grab!
     assert not @map, "unfinished evaluation cycle"
     @map, @pending = {}, {}
 
   --- abort an evaluation cycle.
-  --
-  -- Unset the active Registry.
   rollback_eval: =>
+    assert @map, "no eval cycle to abort"
     for { :tag, :expr } in *@pending
       expr\destroy!
 
@@ -61,11 +57,10 @@ class Registry
   --- end an evaluation cycle.
   --
   -- Register all pending `Tag`s and destroy all orphaned registrations.
-  -- Unset the active Registry.
   -- @treturn bool whether any changes to the AST were made
   end_eval: =>
     for tag, val in pairs @last_map
-      val\destroy! unless @map[tag]
+      val\destroy!
 
     for { :tag, :expr } in *@pending
       -- tag was solved by another pending registration
@@ -82,16 +77,6 @@ class Registry
 
     dirty
 
-  --- set the active Registry.
-  grab: =>
-    assert not @prev, "already have a previous registry? #{@prev}"
-    @prev, Registry.active_registry = Registry.active_registry, @
-
-  --- unset the active Registry.
-  release: =>
-    assert @ == Registry.active_registry, "not the active registry!"
-    Registry.active_registry, @prev = @prev, nil
-
   --- destroy this Registry and all associated Registrations.
   -- needs to be called *after* `:eval`.
   destroy: =>
@@ -109,13 +94,6 @@ class Registry
   new: =>
     @last_map = {}
 
-  --- get the active Registry.
-  --
-  -- Raises an error when there is no active Registry.
-  --
-  -- @treturn Registry
-  @active: -> assert Registry.active_registry, "no active Registry!"
-
 class SimpleRegistry extends Registry
   new: =>
     @cnt = 1
@@ -127,11 +105,6 @@ class SimpleRegistry extends Registry
   last: (index) =>
   register: (index, expr) =>
 
-  wrap: (fn) => (...) ->
-    @grab!
-    with fn ...
-      @release!
-
 {
   :Registry
   :SimpleRegistry
diff --git a/alv/tag.moon b/alv/tag.moon
index d7becab..4b39bcb 100644
--- a/alv/tag.moon
+++ b/alv/tag.moon
@@ -30,14 +30,14 @@ class Tag
   -- @treturn ?any
   last: =>
     if index = @index!
-      Registry.active!\last index
+      COPILOT.active_module.registry\last index
 
   --- register `expr` for this tag for the current eval cycle.
   --
   -- Will mark blank tags for auto-assignment at the end of the eval cycle.
   --
   -- @tparam any expr the value to register
-  register: (expr) => Registry.active!\register @, expr
+  register: (expr) => COPILOT.active_module.registry\register @, expr
 
   --- create a copy of this tag scoped to a `parent` tag.
   --
@@ -48,7 +48,7 @@ class Tag
   clone: (parent) =>
     -- ensure this tag is registered for the current eval cycle,
     -- even if it is blank and has no associated value
-    Registry.active!\register @, dummy, true
+    COPILOT.active_module.registry\register @, dummy, true
 
     assert parent, "need parent to clone!"
     ClonedTag @, parent