slices will reuse local vars for list

Author: leafo

moonscript/compile.lua

@@ -389,6 +389,9 @@ do
       if t == NameProxy or t == LocalName then
         return true
       end
+      if t == "table" and node[1] == "chain" and #node == 2 then
+        return self:is_local(node[2])
+      end
       return false
     end,
     free_name = function(self, prefix, dont_put)

moonscript/compile.moon

@@ -257,6 +257,10 @@ class Block
     t = mtype node
     return @has_name(node, false) if t == "string"
     return true if t == NameProxy or t == LocalName
+
+    if t == "table" and node[1] == "chain" and #node == 2
+      return @is_local node[2]
+
     false
 
   free_name: (prefix, dont_put) =>

moonscript/transform.lua

@@ -716,6 +716,9 @@ Statement = Transformer({
         local slice = list[#list]
         table.remove(list)
         table.remove(slice, 1)
+        if self:is_local(list) then
+          list_name = list
+        end
         if slice[2] and slice[2] ~= "" then
           local max_tmp_name = NameProxy("max")
           slice_var = build.assign_one(max_tmp_name, slice[2])

moonscript/transform.moon

@@ -400,6 +400,7 @@ Statement = Transformer {
       list = source[2]
 
       index_name = NameProxy "index"
+
       list_name = @is_local(list) and list or NameProxy "list"
 
       slice_var = nil
@@ -408,6 +409,8 @@ Statement = Transformer {
         table.remove list
         table.remove slice, 1
 
+        list_name = list if @is_local list
+
         slice[2] = if slice[2] and slice[2] != ""
           max_tmp_name = NameProxy "max"
           slice_var = build.assign_one max_tmp_name, slice[2]

spec/outputs/lists.lua

@@ -221,38 +221,32 @@ x = {
   6,
   7
 }
-local _list_0 = x
 local _max_0 = -5
-for _index_0 = 2, _max_0 < 0 and #_list_0 + _max_0 or _max_0, 2 do
-  local y = _list_0[_index_0]
+for _index_0 = 2, _max_0 < 0 and #x + _max_0 or _max_0, 2 do
+  local y = x[_index_0]
   print(y)
 end
-local _list_1 = x
 local _max_1 = 3
-for _index_0 = 1, _max_1 < 0 and #_list_1 + _max_1 or _max_1 do
-  local y = _list_1[_index_0]
+for _index_0 = 1, _max_1 < 0 and #x + _max_1 or _max_1 do
+  local y = x[_index_0]
   print(y)
 end
-local _list_2 = x
-for _index_0 = 2, #_list_2 do
-  local y = _list_2[_index_0]
+for _index_0 = 2, #x do
+  local y = x[_index_0]
   print(y)
 end
-local _list_3 = x
-for _index_0 = 1, #_list_3, 2 do
-  local y = _list_3[_index_0]
+for _index_0 = 1, #x, 2 do
+  local y = x[_index_0]
   print(y)
 end
-local _list_4 = x
-for _index_0 = 2, #_list_4, 2 do
-  local y = _list_4[_index_0]
+for _index_0 = 2, #x, 2 do
+  local y = x[_index_0]
   print(y)
 end
 local a, b, c = 1, 5, 2
-local _list_5 = x
 local _max_2 = b
-for _index_0 = a, _max_2 < 0 and #_list_5 + _max_2 or _max_2, c do
-  local y = _list_5[_index_0]
+for _index_0 = a, _max_2 < 0 and #x + _max_2 or _max_2, c do
+  local y = x[_index_0]
   print(y)
 end
 local normal
@@ -274,9 +268,9 @@ for _index_0 = 1, #test do
 end
 local _
 _ = function()
-  local _list_6 = rows
-  for _index_0 = 1, #_list_6 do
-    local row = _list_6[_index_0]
+  local _list_0 = rows
+  for _index_0 = 1, #_list_0 do
+    local row = _list_0[_index_0]
     a = b
   end
 end