copy value before making accumlator for unpack foreach

Author: leafo

moonscript/compile/value.lua

@@ -46,9 +46,9 @@ local value_compilers = {
     do
       local _with_0 = self:line()
       _with_0:append_list((function()
+        local _list_0 = node
         local _accum_0 = { }
         local _len_0 = 1
-        local _list_0 = node
         for _index_0 = 2, #_list_0 do
           local v = _list_0[_index_0]
           _accum_0[_len_0] = self:value(v)

moonscript/errors.lua

@@ -42,9 +42,9 @@ truncate_traceback = function(traceback, chunk_func)
     end
     stop = stop - 1
   end
+  local _list_0 = traceback
   traceback = { }
   local _len_0 = 1
-  local _list_0 = traceback
   local _max_0 = stop
   for _index_0 = 1, _max_0 < 0 and #_list_0 + _max_0 or _max_0 do
     local t = _list_0[_index_0]

moonscript/transform.lua

@@ -349,11 +349,13 @@ Statement = Transformer({
       if "comprehension" == _exp_0 then
         local first_name = names[1]
         local a = Accumulator(first_name)
-        node = self.transform.statement(first_value, function(exp)
+        local action
+        action = function(exp)
           return a:mutate_body({
             exp
           })
-        end)
+        end
+        node = self.transform.statement(first_value, action, node)
         return a:wrap(node, "group")
       end
     end
@@ -585,9 +587,9 @@ Statement = Transformer({
       wrapped = build.group({
         build.declare({
           names = (function()
+            local _list_0 = stm[2]
             local _accum_0 = { }
             local _len_0 = 1
-            local _list_0 = stm[2]
             for _index_0 = 1, #_list_0 do
               local name = _list_0[_index_0]
               if type(name) == "string" then
@@ -699,7 +701,7 @@ Statement = Transformer({
       end)()
     })
   end,
-  foreach = function(self, node)
+  foreach = function(self, node, _, parent_assign)
     smart_node(node)
     local source = unpack(node.iter)
     local destructures = { }
@@ -727,7 +729,11 @@ Statement = Transformer({
     if ntype(source) == "unpack" then
       local list = source[2]
       local index_name = NameProxy("index")
-      local list_name = self:is_local(list) and list or NameProxy("list")
+      local assign_name
+      if parent_assign then
+        assign_name = parent_assign[2][1]
+      end
+      local list_name = assign_name ~= list and self:is_local(list) and list or NameProxy("list")
       local slice_var = nil
       local bounds
       if is_slice(list) then
@@ -768,7 +774,7 @@ Statement = Transformer({
           }
         }
       end
-      return build.group({
+      local out = build.group({
         list_name ~= list and build.assign_one(list_name, list) or NOOP,
         slice_var or NOOP,
         build["for"]({
@@ -786,6 +792,8 @@ Statement = Transformer({
           }
         })
       })
+      out.has_unpack_copy = true
+      return out
     end
     node.body = with_continue_listener(node.body)
   end,
@@ -1085,9 +1093,9 @@ Statement = Transformer({
           end
           return self:set("super", function(block, chain)
             if chain then
+              local _list_0 = chain
               local slice = { }
               local _len_0 = 1
-              local _list_0 = chain
               for _index_0 = 3, #_list_0 do
                 local item = _list_0[_index_0]
                 slice[_len_0] = item
@@ -1244,7 +1252,16 @@ do
       if group_type == nil then
         group_type = "block_exp"
       end
+      local copy_list
+      if rawget(node, "has_unpack_copy") then
+        do
+          local _with_0 = node[2][1]
+          node[2][1] = NOOP
+          copy_list = _with_0
+        end
+      end
       return build[group_type]({
+        copy_list or NOOP,
         build.assign_one(self.accum_name, build.table()),
         build.assign_one(self.len_name, 1),
         node,

moonscript/transform.moon

@@ -181,8 +181,8 @@ Statement = Transformer {
           first_name = names[1]
 
           a = Accumulator first_name
-          node = @transform.statement first_value, (exp) ->
-            a\mutate_body { exp }
+          action = (exp) -> a\mutate_body { exp }
+          node = @transform.statement first_value, action, node
 
           return a\wrap node, "group"
 
@@ -389,7 +389,7 @@ Statement = Transformer {
         ret scope_name
     }
 
-  foreach: (node) =>
+  foreach: (node, _, parent_assign) =>
     smart_node node
     source = unpack node.iter
 
@@ -409,7 +409,8 @@ Statement = Transformer {
       list = source[2]
 
       index_name = NameProxy "index"
-      list_name = @is_local(list) and list or NameProxy "list"
+      assign_name = parent_assign[2][1] if parent_assign
+      list_name = assign_name != list and @is_local(list) and list or NameProxy "list"
 
       slice_var = nil
       bounds = if is_slice list
@@ -430,7 +431,7 @@ Statement = Transformer {
       else
         {1, {"length", list_name}}
 
-      return build.group {
+      out = build.group {
         list_name != list and build.assign_one(list_name, list) or NOOP
         slice_var or NOOP
         build["for"] {
@@ -443,6 +444,9 @@ Statement = Transformer {
         }
       }
 
+      out.has_unpack_copy = true
+      return out
+
     node.body = with_continue_listener node.body
 
   while: (node) =>
@@ -721,7 +725,12 @@ class Accumulator
 
   -- wrap the node into a block_exp
   wrap: (node, group_type="block_exp") =>
+    copy_list = if rawget node, "has_unpack_copy"
+      with node[2][1]
+        node[2][1] = NOOP
+
     build[group_type] {
+      copy_list or NOOP
       build.assign_one @accum_name, build.table!
       build.assign_one @len_name, 1
       node

moonscript/types.lua

@@ -1,14 +1,18 @@
 local util = require("moonscript.util")
-local data = require("moonscript.data")
+local Set
+do
+  local _table_0 = require("moonscript.data")
+  Set = _table_0.Set
+end
 local insert = table.insert
 local unpack = util.unpack
-local manual_return = data.Set({
+local manual_return = Set({
   "foreach",
   "for",
   "while",
   "return"
 })
-local cascading = data.Set({
+local cascading = Set({
   "if",
   "unless",
   "with",

moonscript/types.moon

@@ -1,17 +1,17 @@
 
 util = require "moonscript.util"
-data = require "moonscript.data"
+import Set from require "moonscript.data"
 
 import insert from table
 import unpack from util
 
 -- implicit return does not work on these statements
-manual_return = data.Set{"foreach", "for", "while", "return"}
+manual_return = Set{"foreach", "for", "while", "return"}
 
 -- Assigns and returns are bubbled into their bodies.
 -- All cascading statement transform functions accept a second arugment that
 -- is the transformation to apply to the last statement in their body
-cascading = data.Set{ "if", "unless", "with", "switch", "class", "do" }
+cascading = Set{ "if", "unless", "with", "switch", "class", "do" }
 
 -- type of node as string
 ntype = (node) ->

spec/outputs/bubbling.lua

@@ -40,11 +40,11 @@ end)()
 local m
 m = function(...)
   return (function(...)
-    local _accum_0 = { }
-    local _len_1 = 1
     local _list_0 = {
       ...
     }
+    local _accum_0 = { }
+    local _len_1 = 1
     for _index_0 = 1, #_list_0 do
       local x = _list_0[_index_0]
       if f(...) > 4 then
@@ -68,11 +68,11 @@ local x = (function(...)
   end
   return _accum_0
 end)(...)
-local y = { }
-local _len_1 = 1
 local _list_0 = {
   ...
 }
+local y = { }
+local _len_1 = 1
 for _index_0 = 1, #_list_0 do
   x = _list_0[_index_0]
   y[_len_1] = x

thoughts

@@ -37,4 +37,5 @@ x = for thing in *things
 	if is_important thing
 		break thing 
 
+-- all function literals have a string that is their function definition