moved value loops to transformer

moonscript/compile/value.lua

@@ -35,45 +35,6 @@ table_append = function(name, len, value)
     }
   }
 end
-local create_accumulate_wrapper
-create_accumulate_wrapper = function(block_pos)
-  return function(self, node)
-    do
-      local _with_0 = self:block("(function()", "end)()")
-      local accum_name = _with_0:init_free_var("accum", {
-        "table"
-      })
-      local count_name = _with_0:init_free_var("len", 0)
-      local value_name = _with_0:free_name("value", true)
-      local inner = node[block_pos]
-      inner[#inner] = {
-        "assign",
-        {
-          value_name
-        },
-        {
-          inner[#inner]
-        }
-      }
-      insert(inner, {
-        "if",
-        {
-          "exp",
-          value_name,
-          "~=",
-          "nil"
-        },
-        table_append(accum_name, count_name, value_name)
-      })
-      _with_0:stm(node)
-      _with_0:stm({
-        "return",
-        accum_name
-      })
-      return _with_0
-    end
-  end
-end
 value_compile = {
   exp = function(self, node)
     local _comp
@@ -169,9 +130,6 @@ value_compile = {
       return _with_0
     end
   end,
-  ["for"] = create_accumulate_wrapper(4),
-  foreach = create_accumulate_wrapper(4),
-  ["while"] = create_accumulate_wrapper(3),
   chain = function(self, node)
     local callee = node[2]
     if callee == -1 then

moonscript/compile/value.moon

@@ -18,23 +18,6 @@ table_append = (name, len, value) ->
       {"chain", name, {"index", len}} }, { value }}
   }
 
-create_accumulate_wrapper = (block_pos) ->
-  (node) =>
-    with @block "(function()", "end)()"
-      accum_name = \init_free_var "accum", {"table"}
-      count_name = \init_free_var "len", 0
-      value_name = \free_name "value", true
-
-      inner = node[block_pos]
-      inner[#inner] = {"assign", {value_name}, {inner[#inner]}}
-      insert inner, {
-        "if", {"exp", value_name, "~=", "nil"},
-        table_append accum_name, count_name, value_name
-      }
-
-      \stm node
-      \stm {"return", accum_name}
-
 value_compile =
   exp: (node) =>
     _comp = (i, value) ->
@@ -87,10 +70,6 @@ value_compile =
       else
         "(function()", "end)()"
 
-  for: create_accumulate_wrapper 4
-  foreach: create_accumulate_wrapper 4
-  while: create_accumulate_wrapper 3
-
   chain: (node) =>
     callee = node[2]
 

moonscript/transform.lua

@@ -45,6 +45,15 @@ NameProxy = (function(_parent_0)
         unpack(items)
       })
     end,
+    index = function(self, key)
+      return build.chain({
+        base = self,
+        {
+          "index",
+          key
+        }
+      })
+    end,
     __tostring = function(self)
       if self.name then
         return ("name<%s>"):format(self.name)
@@ -99,12 +108,40 @@ Run = (function(_parent_0)
   _base_0.__class = _class_0
   return _class_0
 end)()
+local apply_to_last
+apply_to_last = function(stms, fn)
+  local last_exp_id = 0
+  for i = #stms, 1, -1 do
+    local stm = stms[i]
+    if stm and util.moon.type(stm) ~= Run then
+      last_exp_id = i
+      break
+    end
+  end
+  return (function()
+    local _accum_0 = { }
+    local _len_0 = 0
+    for i, stm in ipairs(stms) do
+      local _value_0
+      if i == last_exp_id then
+        _value_0 = fn(stm)
+      else
+        _value_0 = stm
+      end
+      if _value_0 ~= nil then
+        _len_0 = _len_0 + 1
+        _accum_0[_len_0] = _value_0
+      end
+    end
+    return _accum_0
+  end)()
+end
 local constructor_name = "new"
-local transformer
-transformer = function(transformers)
+local Transformer
+Transformer = function(transformers)
   return function(n)
     while true do
-      transformer = transformers[ntype(n)]
+      local transformer = transformers[ntype(n)]
       local res
       if transformer then
         res = transformer(n) or n
@@ -118,7 +155,7 @@ transformer = function(transformers)
     end
   end
 end
-stm = transformer({
+stm = Transformer({
   class = function(node)
     local _, name, parent_val, tbl = unpack(node)
     local constructor = nil
@@ -333,7 +370,45 @@ stm = transformer({
     return value
   end
 })
-value = transformer({
+local create_accumulator
+create_accumulator = function(body_index)
+  return function(node)
+    local accum_name = NameProxy("accum")
+    local value_name = NameProxy("value")
+    local len_name = NameProxy("len")
+    local body = apply_to_last(node[body_index], function(n)
+      return build.assign_one(value_name, n)
+    end)
+    table.insert(body, build["if"]({
+      cond = {
+        "exp",
+        value_name,
+        "!=",
+        "nil"
+      },
+      ["then"] = {
+        {
+          "update",
+          len_name,
+          "+=",
+          1
+        },
+        build.assign_one(accum_name:index(len_name), value_name)
+      }
+    }))
+    node[body_index] = body
+    return build.block_exp({
+      build.assign_one(accum_name, build.table()),
+      build.assign_one(len_name, 0),
+      node,
+      accum_name
+    })
+  end
+end
+value = Transformer({
+  ["for"] = create_accumulator(4),
+  foreach = create_accumulator(4),
+  ["while"] = create_accumulator(3),
   chain = function(node)
     local stub = node[#node]
     if type(stub) == "table" and stub[1] == "colon_stub" then

moonscript/transform.moon

@@ -32,6 +32,11 @@ class NameProxy
       unpack items
     }
 
+  index: (key) =>
+    build.chain {
+      base: self, {"index", key}
+    }
+
   __tostring: =>
     if @name
       ("name<%s>")\format @name
@@ -45,9 +50,25 @@ class Run
   call: (state) =>
     self.fn state
 
+-- transform the last stm is a list of stms
+apply_to_last = (stms, fn using nil) ->
+  -- find last (real) exp
+  last_exp_id = 0
+  for i = #stms, 1, -1
+    stm = stms[i]
+    if stm and util.moon.type(stm) != Run
+      last_exp_id = i
+      break
+
+  return for i, stm in ipairs stms
+    if i == last_exp_id
+      fn stm
+    else
+      stm
+
 constructor_name = "new"
 
-transformer = (transformers) ->
+Transformer = (transformers) ->
   (n) ->
     while true
       transformer = transformers[ntype n]
@@ -58,7 +79,7 @@ transformer = (transformers) ->
       return n if res == n
       n = res
 
-stm = transformer {
+stm = Transformer {
   class: (node using nil) ->
     _, name, parent_val, tbl = unpack node
 
@@ -169,7 +190,37 @@ stm = transformer {
     value
 }
 
-value = transformer {
+create_accumulator = (body_index) ->
+  (node) ->
+    accum_name = NameProxy "accum"
+    value_name = NameProxy "value"
+    len_name = NameProxy "len"
+
+    body = apply_to_last node[body_index], (n) ->
+      build.assign_one value_name, n
+
+    table.insert body, build["if"] {
+      cond: {"exp", value_name, "!=", "nil"}
+      then: {
+        {"update", len_name, "+=", 1}
+        build.assign_one accum_name\index(len_name), value_name
+      }
+    }
+
+    node[body_index] = body
+
+    build.block_exp {
+      build.assign_one accum_name, build.table!
+      build.assign_one len_name, 0
+      node
+      accum_name
+    }
+
+value = Transformer {
+  for: create_accumulator 4
+  foreach: create_accumulator 4
+  while: create_accumulator 3
+
   -- pull out colon chain
   chain: (node) ->
     stub = node[#node]