refactor transformers to run with context of current block

Author: leafo

moonscript/compile.lua

@@ -344,7 +344,7 @@ Block = (function()
       return self:value(node)
     end,
     value = function(self, node, ...)
-      node = self.root.transform.value(node)
+      node = self.transform.value(node)
       local action
       if type(node) ~= "table" then
         action = "raw_value"
@@ -380,7 +380,7 @@ Block = (function()
       if not node then
         return 
       end
-      node = self.root.transform.statement(node)
+      node = self.transform.statement(node)
       local fn = line_compile[ntype(node)]
       if not fn then
         if has_value(node) then
@@ -429,6 +429,13 @@ Block = (function()
       self._posmap = { }
       self._names = { }
       self._state = { }
+      do
+        local _with_0 = transform
+        self.transform = {
+          value = _with_0.Value:bind(self),
+          statement = _with_0.Statement:bind(self)
+        }
+      end
       if self.parent then
         self.root = self.parent.root
         self.indent = self.parent.indent + 1
@@ -481,10 +488,6 @@ RootBlock = (function()
   local _class_0 = setmetatable({
     __init = function(self, ...)
       self.root = self
-      self.transform = {
-        value = transform.Value:instance(self),
-        statement = transform.Statement:instance(self)
-      }
       return _parent_0.__init(self, ...)
     end,
     __base = _base_0,

moonscript/compile.moon

@@ -71,6 +71,12 @@ class Block
     @_names = {}
     @_state = {}
 
+    with transform
+      @transform = {
+        value: .Value\bind self
+        statement: .Statement\bind self
+      }
+
     if @parent
       @root = @parent.root
       @indent = @parent.indent + 1
@@ -239,7 +245,7 @@ class Block
   -- line wise compile functions
   name: (node) => @value node
   value: (node, ...) =>
-    node = @root.transform.value node
+    node = @transform.value node
     action = if type(node) != "table"
       "raw_value"
     else
@@ -257,7 +263,7 @@ class Block
 
   stm: (node, ...) =>
     return if not node -- skip blank statements
-    node = @root.transform.statement node
+    node = @transform.statement node
     fn = line_compile[ntype(node)]
     if not fn
       -- coerce value into statement
@@ -279,10 +285,6 @@ class Block
 class RootBlock extends Block
   new: (...) =>
     @root = self
-    @transform = {
-      value: transform.Value\instance self
-      statement: transform.Statement\instance self
-    }
     super ...
 
   __tostring: => "RootBlock<>"

moonscript/transform.lua

@@ -297,12 +297,15 @@ Transformer = (function()
         end
         node = res
       end
+      return node
     end,
-    __call = function(self, node, ...)
-      return self:transform(self.scope, node, ...)
+    bind = function(self, scope)
+      return function(...)
+        return self:transform(scope, ...)
+      end
     end,
-    instance = function(self, scope)
-      return Transformer(self.transformers, scope)
+    __call = function(self, ...)
+      return self:transform(...)
     end,
     can_transform = function(self, node)
       return self.transformers[ntype(node)] ~= nil
@@ -313,9 +316,11 @@ Transformer = (function()
     setmetatable(_base_0, _parent_0.__base)
   end
   local _class_0 = setmetatable({
-    __init = function(self, transformers, scope)
-      self.transformers, self.scope = transformers, scope
-      self.seen_nodes = { }
+    __init = function(self, transformers)
+      self.transformers = transformers
+      self.seen_nodes = setmetatable({ }, {
+        __mode = "k"
+      })
     end,
     __base = _base_0,
     __name = "Transformer",

moonscript/transform.moon

@@ -117,11 +117,10 @@ expand_elseif_assign = (ifstm) ->
 constructor_name = "new"
 
 class Transformer
-  new: (@transformers, @scope) =>
-    @seen_nodes = {}
+  new: (@transformers) =>
+    @seen_nodes = setmetatable {}, __mode: "k"
 
   transform: (scope, node, ...) =>
-    -- print scope, node, ...
     return node if @seen_nodes[node]
     @seen_nodes[node] = true
     while true
@@ -132,12 +131,12 @@ class Transformer
         node
       return node if res == node
       node = res
+    node
 
-  __call: (node, ...) =>
-    @transform @scope, node, ...
+  bind: (scope) =>
+    (...) -> @transform scope, ...
 
-  instance: (scope) =>
-    Transformer @transformers, scope
+  __call: (...) => @transform ...
 
   can_transform: (node) =>
     @transformers[ntype node] != nil