expose Tag to Ops

7 files changed, 41 insertions, 43 deletions

diff --git a/alv/base/builtin.moon b/alv/base/builtin.moon
index 558a65a..02f551c 100644
--- a/alv/base/builtin.moon
+++ b/alv/base/builtin.moon
@@ -19,7 +19,7 @@ class Builtin
   -- @tparam Value head the (`AST:eval`d) `head` of the Cell to evaluate
   new: (@cell, @head) =>
     @tag = @cell.tag
-    @tag\register @
+    @tag.builtin = @
 
   --- perform the actual evaluation.
   --
diff --git a/alv/invoke.moon b/alv/invoke.moon
index 56e6511..02479df 100644
--- a/alv/invoke.moon
+++ b/alv/invoke.moon
@@ -38,6 +38,8 @@ class op_invoke extends Builtin
       def = @head\unwrap T.opdef, "cant op-invoke #{@head}"
       @op = def!
 
+    @op.tag = @tag
+
   --- `Builtin:destroy` implementation.
   --
   -- calls `op`:@{Op:destroy|destroy}.
diff --git a/alv/module.moon b/alv/module.moon
index ab98436..2fa24d9 100644
--- a/alv/module.moon
+++ b/alv/module.moon
@@ -42,6 +42,8 @@ class Module
     @ast = Error.wrap "parsing '#{@name true}'", -> program\match @slurp!
     assert @ast, Error 'syntax', "failed to parse"
 
+    @registry\scan_ast @ast
+
     scope = Scope builtins!, parent_scope
     @root = Error.wrap "evaluating '#{@name true}'", @ast\eval, scope, @registry
 
diff --git a/alv/registry.moon b/alv/registry.moon
index 0d37a5c..35f396d 100644
--- a/alv/registry.moon
+++ b/alv/registry.moon
@@ -11,27 +11,25 @@ class Registry
   --
   -- @tparam number|string index the registration index
   -- @treturn any
-  last: (index) => @last_map[index]
+  last: (index) => if tag = @last_map[index] then tag.builtin
 
   --- set the current registration.
   --
   -- @tparam Tag tag the Tag to register
   -- @tparam any expr the registration value
   -- @tparam[default=false] boolean ignore_dup ignore duplicate registrations
-  register: (tag, expr, ignore_dup=false) =>
+  register: (tag, ignore_dup=false) =>
     index = tag\index!
 
-    if index
-      if not @map[index] or ignore_dup
-        L\trace "reg: setting #{index} to #{expr}"
-        @map[index] = expr
-      else
+    if index and not @map[index] or ignore_dup
+      @map[index] = tag
+    else
+      if index
         L\warn "duplicate tag [#{index}], reassigning repeated occurrence"
         tag\set nil
-        table.insert @pending, { :tag, :expr }
-    else
-      L\trace "reg: init #{tag} to #{expr}"
-      table.insert @pending, { :tag, :expr }
+
+      table.insert @pending, tag
+      L\trace "reg: setting #{index} to #{expr}"
 
 --- members
 -- @section members
@@ -47,20 +45,24 @@ class Registry
   --- abort an evaluation cycle.
   rollback_eval: =>
     assert @map, "no eval cycle to abort"
-    for { :tag, :expr } in *@pending
-      expr\destroy!
+    for tag in *@pending
+      if builtin = tag.builtin
+        builtin\destroy!
 
     @map, @pending = nil, nil
 
-  --- end an evaluation cycle.
-  --
-  -- Register all pending `Tag`s and destroy all orphaned registrations.
-  -- @treturn bool whether any changes to the AST were made
-  end_eval: =>
-    for tag, val in pairs @last_map
-      val\destroy!
+  scan_ast_node: (ast) =>
+    if ast.tag
+      @register ast.tag
 
-    for { :tag, :expr } in *@pending
+    if ast.children
+      for child in *ast.children
+        @scan_ast_node child
+
+  scan_ast: (ast) =>
+    @scan_ast_node ast
+
+    for tag in *@pending
       -- tag was solved by another pending registration
       -- (e.g. first [A] is solved, then [5.A] is solved)
       continue if tag\index!
@@ -68,7 +70,14 @@ class Registry
       next_tag = #@map + 1
       L\trace "assigned new tag #{next_tag} to #{tag} #{expr}"
       tag\set next_tag
-      @map[tag\index!] = expr
+
+  --- end an evaluation cycle.
+  --
+  -- Register all pending `Tag`s and destroy all orphaned registrations.
+  -- @treturn bool whether any changes to the AST were made
+  end_eval: =>
+    for index, tag in pairs @last_map
+      tag.builtin\destroy!
 
     dirty = #@pending > 0
     @last_map, @map, @pending = @map, nil, nil
@@ -79,8 +88,8 @@ class Registry
   -- needs to be called *after* `:eval`.
   destroy: =>
     assert not @tag, "unfinished evaluation cycle"
-    for tag, val in pairs @last_map
-      val\destroy!
+    for index, tag in pairs @last_map
+      tag.builtin\destroy!
 
     @last_map = {}
 
diff --git a/alv/result/const.moon b/alv/result/const.moon
index 43f97a0..fae47c4 100644
--- a/alv/result/const.moon
+++ b/alv/result/const.moon
@@ -53,6 +53,8 @@ class Constant extends Result
 -- `Constant` implements the `AST` interface.
 -- @section ast
 
+  register: =>
+
   --- evaluate this literal constant.
   --
   -- Throws an error if `type` is not a literal (`num`, `str` or `sym`).
diff --git a/alv/tag.moon b/alv/tag.moon
index d46bf0a..ed59be6 100644
--- a/alv/tag.moon
+++ b/alv/tag.moon
@@ -11,13 +11,6 @@ import Registry from require 'alv.registry'
 
 local ClonedTag
 
-class DummyReg
-  destroy: =>
-
-  __tostring: => "<dummy>"
-
-dummy = DummyReg!
-
 class Tag
 --- members
 -- @section members
@@ -32,13 +25,6 @@ class Tag
     if index = @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) => COPILOT.active_module.registry\register @, expr
-
   --- create a copy of this tag scoped to a `parent` tag.
   --
   -- Will mark blank tags for auto-assignment at the end of the eval cycle.
@@ -46,10 +32,6 @@ class Tag
   -- @tparam Tag parent the parent tag
   -- @treturn Tag the cloned tag
   clone: (parent) =>
-    -- ensure this tag is registered for the current eval cycle,
-    -- even if it is blank and has no associated value
-    COPILOT.active_module.registry\register @, dummy, true
-
     assert parent, "need parent to clone!"
     ClonedTag @, parent
 
diff --git a/spec/test_setup.moon b/spec/test_setup.moon
index 678cfb7..53d1451 100644
--- a/spec/test_setup.moon
+++ b/spec/test_setup.moon
@@ -90,5 +90,6 @@ class TestPilot extends Copilot
       tail: -> tail
       tag: Tag.blank!
 
+    COPILOT.active_module.registry\scan_ast fake_cell
     op_invoke\eval_cell fake_cell, Scope!, Constant.wrap op
 }