classes can be expressions, classes don't require name or body anymore

moonscript/parse.lua

@@ -383,7 +383,7 @@ local build_grammar = wrap_env(function()
 		Line = (CheckIndent * Statement + Space * #Stop),
 
 		Statement = pos(
-				Import + While + With + For + ForEach + Switch + Return + ClassDecl +
+				Import + While + With + For + ForEach + Switch + Return +
 				Local + Export + BreakLoop +
 				Ct(ExpList) * (Update + Assign)^-1 / format_assign
 			) * Space * ((
@@ -467,6 +467,7 @@ local build_grammar = wrap_env(function()
 			If + Unless +
 			Switch +
 			With +
+			ClassDecl +
 			ForEach + For + While +
 			Cmt(Do, check_do) +
 			sym"-" * -SomeSpace * Exp / mark"minus" +
@@ -552,7 +553,7 @@ local build_grammar = wrap_env(function()
 		TableBlockInner = Ct(KeyValueLine * (SpaceBreak^1 * KeyValueLine)^0),
 		TableBlock = SpaceBreak^1 * Advance * ensure(TableBlockInner, PopIndent) / mark"table",
 
-		ClassDecl = key"class" * Assignable * (key"extends" * PreventIndent * ensure(Exp, PopIndent) + C"")^-1 * ClassBlock / mark"class",
+		ClassDecl = key"class" * (Assignable + Cc(nil)) * (key"extends" * PreventIndent * ensure(Exp, PopIndent) + C"")^-1 * (ClassBlock + Ct("")) / mark"class",
 
 		ClassBlock = SpaceBreak^1 * Advance *
 			Ct(ClassLine * (SpaceBreak^1 * ClassLine)^0) * PopIndent,

moonscript/transform.lua

@@ -975,20 +975,23 @@ Statement = Transformer({
       constructor.arrow = "fat"
     end
     local real_name
-    if ntype(name) == "chain" then
+    local _exp_0 = ntype(name)
+    if "chain" == _exp_0 then
       local last = name[#name]
-      local _exp_0 = ntype(last)
+      local _exp_1 = ntype(last)
-      if "dot" == _exp_0 then
+      if "dot" == _exp_1 then
         real_name = {
           "string",
           '"',
           last[2]
         }
-      elseif "index" == _exp_0 then
+      elseif "index" == _exp_1 then
         real_name = last[2]
       else
         real_name = "nil"
       end
+    elseif "nil" == _exp_0 then
+      real_name = "nil"
     else
       real_name = {
         "string",
@@ -1112,7 +1115,9 @@ Statement = Transformer({
       local _with_0 = build
       local out_body = {
         Run(function(self)
+          if name then
             self:put_name(name)
+          end
           return self:set("super", function(block, chain)
             if chain then
               local slice = (function()
@@ -1134,8 +1139,8 @@ Statement = Transformer({
               if head == nil then
                 return parent_cls_name
               end
-              local _exp_0 = head[1]
+              local _exp_1 = head[1]
-              if "call" == _exp_0 then
+              if "call" == _exp_1 then
                 local calling_name = block:get("current_block")
                 slice[1] = {
                   "call",
@@ -1155,7 +1160,7 @@ Statement = Transformer({
                     calling_name
                   })
                 end
-              elseif "colon" == _exp_0 then
+              elseif "colon" == _exp_1 then
                 local call = head[3]
                 insert(new_chain, {
                   "dot",
@@ -1186,7 +1191,7 @@ Statement = Transformer({
           properties
         }),
         _with_0.assign_one(base_name:chain("__index"), base_name),
-        build["if"]({
+        _with_0["if"]({
           cond = parent_cls_name,
           ["then"] = {
             _with_0.chain({
@@ -1215,11 +1220,9 @@ Statement = Transformer({
               _with_0.assign_one(LocalName("self"), cls_name),
               _with_0.group(statements)
             }
-          else
-            return { }
           end
         end)()),
-        build["if"]({
+        _with_0["if"]({
           cond = {
             "exp",
             parent_cls_name,
@@ -1236,7 +1239,13 @@ Statement = Transformer({
             })
           }
         }),
-        _with_0.assign_one(name, cls_name),
+        _with_0.group((function()
+          if name then
+            return {
+              _with_0.assign_one(name, cls_name)
+            }
+          end
+        end)()),
         (function()
           if ret then
             return ret(cls_name)
@@ -1245,15 +1254,17 @@ Statement = Transformer({
       }
       hoist_declarations(out_body)
       value = _with_0.group({
-        (function()
+        _with_0.group((function()
           if ntype(name) == "value" then
-            return _with_0.declare({
+            return {
+              _with_0.declare({
                 names = {
                   name
                 }
               })
+            }
           end
-        end)(),
+        end)()),
         _with_0["do"](out_body)
       })
     end
@@ -1415,6 +1426,11 @@ Value = Transformer({
   decorated = function(self, node)
     return self.transform.statement(node)
   end,
+  class = function(self, node)
+    return build.block_exp({
+      node
+    })
+  end,
   string = function(self, node)
     local delim = node[2]
     local convert_part

moonscript/transform.moon

@@ -505,7 +505,8 @@ Statement = Transformer {
       smart_node constructor
       constructor.arrow = "fat"
 
-    real_name = if ntype(name) == "chain"
+    real_name = switch ntype(name)
+      when "chain"
         last = name[#name]
         switch ntype last
           when "dot"
@@ -514,6 +515,8 @@ Statement = Transformer {
             last[2]
           else
             "nil"
+      when "nil"
+        "nil"
       else
         {"string", '"', name}
 
@@ -569,7 +572,7 @@ Statement = Transformer {
       out_body = {
         Run =>
           -- make sure we don't assign the class to a local inside the do
-          @put_name name
+          @put_name name if name
 
           @set "super", (block, chain) ->
             if chain
@@ -608,7 +611,7 @@ Statement = Transformer {
         .assign_one base_name, {"table", properties}
         .assign_one base_name\chain"__index", base_name
 
-        build["if"] {
+        .if {
           cond: parent_cls_name
           then: {
             .chain {
@@ -624,13 +627,13 @@ Statement = Transformer {
         .assign_one cls_name, cls
         .assign_one base_name\chain"__class", cls_name
 
-        .group if #statements > 0 {
+        .group if #statements > 0 then {
           .assign_one LocalName"self", cls_name
           .group statements
-        } else {}
+        }
 
         -- run the inherited callback
-        build["if"] {
+        .if {
           cond: {"exp",
             parent_cls_name, "and", parent_cls_name\chain "__inherited"
           }
@@ -641,7 +644,10 @@ Statement = Transformer {
           }
         }
 
+        .group if name then {
           .assign_one name, cls_name
+        }
+
         if ret
           ret cls_name
       }
@@ -649,8 +655,9 @@ Statement = Transformer {
       hoist_declarations out_body
 
       value = .group {
-        if ntype(name) == "value"
+        .group if ntype(name) == "value" then {
           .declare names: {name}
+        }
 
         .do out_body
       }
@@ -755,6 +762,9 @@ Value = Transformer {
   decorated: (node) =>
     @transform.statement node
 
+  class: (node) =>
+    build.block_exp { node }
+
   string: (node) =>
     delim = node[2]
 

moonscript/types.lua

@@ -24,10 +24,13 @@ comprehension_has_value = function(comp)
   return is_value(comp[2])
 end
 ntype = function(node)
-  if type(node) ~= "table" then
+  local _exp_0 = type(node)
-    return "value"
+  if "nil" == _exp_0 then
-  else
+    return "nil"
+  elseif "table" == _exp_0 then
     return node[1]
+  else
+    return "value"
   end
 end
 value_is_singular = function(node)
@@ -175,6 +178,9 @@ end
 build = nil
 build = setmetatable({
   group = function(body)
+    if body == nil then
+      body = { }
+    end
     return {
       "group",
       body

moonscript/types.moon

@@ -25,10 +25,13 @@ comprehension_has_value = (comp) ->
 
 -- type of node as string
 ntype = (node) ->
-  if type(node) != "table"
+  switch type node
-    "value"
+    when "nil"
-  else
+      "nil"
+    when "table"
       node[1]
+    else
+      "value"
 
 value_is_singular = (node) ->
   type(node) != "table" or node[1] != "exp" or #node == 2
@@ -102,7 +105,7 @@ make_builder = (name) ->
 
 build = nil
 build = setmetatable {
-  group: (body) ->
+  group: (body={}) ->
     {"group", body}
   do: (body) ->
     {"do", body}

tests/inputs/class.moon

@@ -146,7 +146,14 @@ class a.b["hello"]
 class (-> require "moon")!.Something extends Hello.World
   nil
 
+--
 
+a = class
+b = class Something
+c = class Something extends Hello
+d = class extends World
+
+print (class WhatsUp).__name
 
 --
 

tests/outputs/class.lua

@@ -753,6 +753,202 @@ do
     return require("moon")
   end)().Something = _class_0
 end
+local a
+do
+  local _parent_0 = nil
+  local _base_0 = { }
+  _base_0.__index = _base_0
+  if _parent_0 then
+    setmetatable(_base_0, _parent_0.__base)
+  end
+  local _class_0 = setmetatable({
+    __init = function(self, ...)
+      if _parent_0 then
+        return _parent_0.__init(self, ...)
+      end
+    end,
+    __base = _base_0,
+    __name = nil,
+    __parent = _parent_0
+  }, {
+    __index = function(cls, name)
+      local val = rawget(_base_0, name)
+      if val == nil and _parent_0 then
+        return _parent_0[name]
+      else
+        return val
+      end
+    end,
+    __call = function(cls, ...)
+      local _self_0 = setmetatable({}, _base_0)
+      cls.__init(_self_0, ...)
+      return _self_0
+    end
+  })
+  _base_0.__class = _class_0
+  if _parent_0 and _parent_0.__inherited then
+    _parent_0.__inherited(_parent_0, _class_0)
+  end
+  a = _class_0
+end
+local b
+local Something
+do
+  local _parent_0 = nil
+  local _base_0 = { }
+  _base_0.__index = _base_0
+  if _parent_0 then
+    setmetatable(_base_0, _parent_0.__base)
+  end
+  local _class_0 = setmetatable({
+    __init = function(self, ...)
+      if _parent_0 then
+        return _parent_0.__init(self, ...)
+      end
+    end,
+    __base = _base_0,
+    __name = "Something",
+    __parent = _parent_0
+  }, {
+    __index = function(cls, name)
+      local val = rawget(_base_0, name)
+      if val == nil and _parent_0 then
+        return _parent_0[name]
+      else
+        return val
+      end
+    end,
+    __call = function(cls, ...)
+      local _self_0 = setmetatable({}, _base_0)
+      cls.__init(_self_0, ...)
+      return _self_0
+    end
+  })
+  _base_0.__class = _class_0
+  if _parent_0 and _parent_0.__inherited then
+    _parent_0.__inherited(_parent_0, _class_0)
+  end
+  Something = _class_0
+  b = _class_0
+end
+local c
+do
+  local _parent_0 = Hello
+  local _base_0 = { }
+  _base_0.__index = _base_0
+  if _parent_0 then
+    setmetatable(_base_0, _parent_0.__base)
+  end
+  local _class_0 = setmetatable({
+    __init = function(self, ...)
+      if _parent_0 then
+        return _parent_0.__init(self, ...)
+      end
+    end,
+    __base = _base_0,
+    __name = "Something",
+    __parent = _parent_0
+  }, {
+    __index = function(cls, name)
+      local val = rawget(_base_0, name)
+      if val == nil and _parent_0 then
+        return _parent_0[name]
+      else
+        return val
+      end
+    end,
+    __call = function(cls, ...)
+      local _self_0 = setmetatable({}, _base_0)
+      cls.__init(_self_0, ...)
+      return _self_0
+    end
+  })
+  _base_0.__class = _class_0
+  if _parent_0 and _parent_0.__inherited then
+    _parent_0.__inherited(_parent_0, _class_0)
+  end
+  Something = _class_0
+  c = _class_0
+end
+local d
+do
+  local _parent_0 = World
+  local _base_0 = { }
+  _base_0.__index = _base_0
+  if _parent_0 then
+    setmetatable(_base_0, _parent_0.__base)
+  end
+  local _class_0 = setmetatable({
+    __init = function(self, ...)
+      if _parent_0 then
+        return _parent_0.__init(self, ...)
+      end
+    end,
+    __base = _base_0,
+    __name = nil,
+    __parent = _parent_0
+  }, {
+    __index = function(cls, name)
+      local val = rawget(_base_0, name)
+      if val == nil and _parent_0 then
+        return _parent_0[name]
+      else
+        return val
+      end
+    end,
+    __call = function(cls, ...)
+      local _self_0 = setmetatable({}, _base_0)
+      cls.__init(_self_0, ...)
+      return _self_0
+    end
+  })
+  _base_0.__class = _class_0
+  if _parent_0 and _parent_0.__inherited then
+    _parent_0.__inherited(_parent_0, _class_0)
+  end
+  d = _class_0
+end
+print(((function()
+  local WhatsUp
+  do
+    local _parent_0 = nil
+    local _base_0 = { }
+    _base_0.__index = _base_0
+    if _parent_0 then
+      setmetatable(_base_0, _parent_0.__base)
+    end
+    local _class_0 = setmetatable({
+      __init = function(self, ...)
+        if _parent_0 then
+          return _parent_0.__init(self, ...)
+        end
+      end,
+      __base = _base_0,
+      __name = "WhatsUp",
+      __parent = _parent_0
+    }, {
+      __index = function(cls, name)
+        local val = rawget(_base_0, name)
+        if val == nil and _parent_0 then
+          return _parent_0[name]
+        else
+          return val
+        end
+      end,
+      __call = function(cls, ...)
+        local _self_0 = setmetatable({}, _base_0)
+        cls.__init(_self_0, ...)
+        return _self_0
+      end
+    })
+    _base_0.__class = _class_0
+    if _parent_0 and _parent_0.__inherited then
+      _parent_0.__inherited(_parent_0, _class_0)
+    end
+    WhatsUp = _class_0
+    return _class_0
+  end
+end)()).__name)
 do
   local _parent_0 = nil
   local _base_0 = { }