diff --git a/lib/metaprogramming.nom b/lib/metaprogramming.nom
index 3d29eb2..9b76620 100644
--- a/lib/metaprogramming.nom
+++ b/lib/metaprogramming.nom
@@ -86,6 +86,8 @@ rule [%tree as value] =:
 rule [%tree as lua] =:
     lua expr "compiler:tree_to_lua(vars.tree)"
 
+rule [test, foobar] =: lua expr "print('yup')"
+
 # Compiler tools
 rule [eval %code, run %code] =: compiler "run" [%code]
 
diff --git a/nomsu.lua b/nomsu.lua
index 833c929..3e2a891 100644
--- a/nomsu.lua
+++ b/nomsu.lua
@@ -74,6 +74,11 @@ do
         self:writeln("Defining rule: " .. tostring(spec))
       end
       local invocations, arg_names = self:get_invocations(spec)
+      for i = 2, #invocations do
+        if not utils.equivalent(utils.set(arg_names[invocations[1]]), utils.set(arg_names[invocations[i]])) then
+          self:error("Conflicting argument names " .. tostring(utils.repr(invocations[1])) .. " and " .. tostring(utils.repr(invocations[i])) .. " for " .. tostring(utils.repr(spec)))
+        end
+      end
       local fn_info = {
         fn = fn,
         arg_names = arg_names,
@@ -88,7 +93,7 @@ do
     end,
     get_invocations_from_definition = function(self, def, vars)
       if def.type == "String" then
-        return self:tree_to_value(def, vars)
+        return self.__class:unescape_string(def.value)
       end
       if def.type ~= "List" then
         self:error("Trying to get invocations from " .. tostring(def.type) .. ", but expected List or String.")
@@ -100,7 +105,7 @@ do
         repeat
           local item = _list_0[_index_0]
           if item.type == "String" then
-            insert(invocations, self:tree_to_value(item, vars))
+            insert(invocations, item.value)
             _continue_0 = true
             break
           end
@@ -142,7 +147,6 @@ do
       end
       local invocations = { }
       local arg_names = { }
-      local prev_arg_names = nil
       for _index_0 = 1, #text do
         local _text = text[_index_0]
         local invocation = _text:gsub("'", " '"):gsub("%%%S+", "%%"):gsub("%s+", " ")
@@ -157,13 +161,6 @@ do
           _arg_names = _accum_0
         end
         insert(invocations, invocation)
-        if prev_arg_names then
-          if not utils.equivalent(utils.set(prev_arg_names), utils.set(_arg_names)) then
-            self:error("Conflicting argument names " .. tostring(utils.repr(prev_arg_names)) .. " and " .. tostring(utils.repr(_arg_names)) .. " for " .. tostring(utils.repr(text)))
-          end
-        else
-          prev_arg_names = _arg_names
-        end
         arg_names[invocation] = _arg_names
       end
       return invocations, arg_names
@@ -173,6 +170,11 @@ do
         self:writeln("DEFINING MACRO: " .. tostring(spec) .. tostring(src or ""))
       end
       local invocations, arg_names = self:get_invocations(spec)
+      for i = 2, #invocations do
+        if not utils.equivalent(utils.set(arg_names[invocations[1]]), utils.set(arg_names[invocations[i]])) then
+          self:error("Conflicting argument names " .. tostring(utils.repr(invocations[1])) .. " and " .. tostring(utils.repr(invocations[i])) .. " for " .. tostring(utils.repr(spec)))
+        end
+      end
       local fn_info = {
         fn = lua_gen_fn,
         arg_names = arg_names,
@@ -185,49 +187,6 @@ do
         self.defs[invocation] = fn_info
       end
     end,
-    serialize = function(self, obj)
-      local _exp_0 = type(obj)
-      if "function" == _exp_0 then
-        error("Function serialization is not yet implemented.")
-        return "assert(load(" .. utils.repr(string.dump(obj)) .. "))"
-      elseif "table" == _exp_0 then
-        if utils.is_list(obj) then
-          return "{" .. tostring(table.concat((function()
-            local _accum_0 = { }
-            local _len_0 = 1
-            for _index_0 = 1, #obj do
-              local i = obj[_index_0]
-              _accum_0[_len_0] = self:serialize(i)
-              _len_0 = _len_0 + 1
-            end
-            return _accum_0
-          end)(), ", ")) .. "}"
-        else
-          return "{" .. tostring(table.concat((function()
-            local _accum_0 = { }
-            local _len_0 = 1
-            for k, v in pairs(obj) do
-              _accum_0[_len_0] = "[" .. tostring(self:serialize(k)) .. "]= " .. tostring(self:serialize(v))
-              _len_0 = _len_0 + 1
-            end
-            return _accum_0
-          end)(), ", ")) .. "}"
-        end
-      elseif "number" == _exp_0 then
-        return utils.repr(obj)
-      elseif "string" == _exp_0 then
-        return utils.repr(obj)
-      else
-        return error("Serialization not implemented for: " .. tostring(type(obj)))
-      end
-    end,
-    deserialize = function(self, str)
-      local lua_thunk, err = load("return (function(compiler,vars)\n        return " .. str .. "\n        end)")
-      if not lua_thunk then
-        error("Failed to compile generated code:\n" .. tostring(str) .. "\n\n" .. tostring(err))
-      end
-      return (lua_thunk())(self, { })
-    end,
     parse = function(self, str, filename)
       if self.debug then
         self:writeln("PARSING:\n" .. tostring(str))
@@ -477,10 +436,7 @@ do
           return self.__class:comma_separated_items("compiler:call(", args, ")")
         end
       elseif "String" == _exp_0 then
-        local unescaped = tree.value:gsub("\\(.)", (function(c)
-          return STRING_ESCAPES[c] or c
-        end))
-        return utils.repr(unescaped)
+        return utils.repr(self.__class:unescape_string(tree.value))
       elseif "Longstring" == _exp_0 then
         local concat_parts = { }
         local string_buffer = ""
@@ -751,24 +707,13 @@ do
       end
     end,
     initialize_core = function(self)
-      local as_lua_code
-      as_lua_code = function(self, str, vars)
-        local _exp_0 = str.type
-        if "String" == _exp_0 then
-          return self:tree_to_value(str, vars)
-        elseif "Longstring" == _exp_0 then
-          return self:tree_to_value(str, vars)
-        else
-          return self:tree_to_lua(str)
-        end
-      end
       self:defmacro([[lua block %lua_code]], function(self, vars, kind)
         if kind == "Expression" then
           error("Expected to be in statement.")
         end
         local inner_vars = setmetatable({ }, {
           __index = function(_, key)
-            return "vars[" .. tostring(utils.repr(key)) .. "]"
+            return error("vars[" .. tostring(utils.repr(key)) .. "]")
           end
         })
         return "do\n" .. self:tree_to_value(vars.lua_code, inner_vars) .. "\nend", true
@@ -777,7 +722,7 @@ do
         local lua_code = vars.lua_code.value
         local inner_vars = setmetatable({ }, {
           __index = function(_, key)
-            return "vars[" .. tostring(utils.repr(key)) .. "]"
+            return error("vars[" .. tostring(utils.repr(key)) .. "]")
           end
         })
         return self:tree_to_value(vars.lua_code, inner_vars)
@@ -828,26 +773,29 @@ do
   })
   _base_0.__class = _class_0
   local self = _class_0
+  self.unescape_string = function(self, str)
+    return str:gsub("\\(.)", (function(c)
+      return STRING_ESCAPES[c] or c
+    end))
+  end
   self.comma_separated_items = function(self, open, items, close)
-    return utils.accumulate("\n", function()
-      local buffer = open
-      local so_far = 0
-      for i, item in ipairs(items) do
-        if i < #items then
-          item = item .. ", "
-        end
-        if so_far + #item >= 80 and #buffer > 0 then
-          coroutine.yield(buffer)
-          so_far = so_far - #buffer
-          buffer = item
-        else
-          so_far = so_far + #item
-          buffer = buffer .. item
-        end
+    local bits = {
+      open
+    }
+    local so_far = 0
+    for i, item in ipairs(items) do
+      if i < #items then
+        item = item .. ", "
       end
-      buffer = buffer .. close
-      return coroutine.yield(buffer)
-    end)
+      insert(bits, item)
+      so_far = so_far + #item
+      if so_far >= 80 then
+        insert(bits, "\n")
+        so_far = 0
+      end
+    end
+    insert(bits, close)
+    return table.concat(bits)
   end
   NomsuCompiler = _class_0
 end
diff --git a/nomsu.moon b/nomsu.moon
index ed53b64..ca888a8 100755
--- a/nomsu.moon
+++ b/nomsu.moon
@@ -56,6 +56,7 @@ class NomsuCompiler
         if fn_info == nil
             @error "Undefined function: #{fn_name}"
         if fn_info.whiteset == nil then return true
+        -- TODO: optimize this, maybe by making the callstack a Counter and having a move-to-front optimization on the whitelist
         for caller in *@callstack
             if fn_info.whiteset[caller]
                 return true
@@ -65,13 +66,16 @@ class NomsuCompiler
         if @debug
             @writeln "Defining rule: #{spec}"
         invocations,arg_names = @get_invocations spec
+        for i=2,#invocations
+            if not utils.equivalent(utils.set(arg_names[invocations[1]]), utils.set(arg_names[invocations[i]]))
+                @error("Conflicting argument names #{utils.repr(invocations[1])} and #{utils.repr(invocations[i])} for #{utils.repr(spec)}")
         fn_info = {:fn, :arg_names, :invocations, :src, is_macro:false}
         for invocation in *invocations
             @defs[invocation] = fn_info
     
     get_invocations_from_definition:(def, vars)=>
         if def.type == "String"
-            return @tree_to_value(def, vars)
+            return @@unescape_string(def.value)
 
         if def.type != "List"
             @error "Trying to get invocations from #{def.type}, but expected List or String."
@@ -79,7 +83,7 @@ class NomsuCompiler
         invocations = {}
         for item in *def.value
             if item.type == "String"
-                insert invocations, @tree_to_value(item, vars)
+                insert invocations, item.value
                 continue
             if item.type != "FunctionCall"
                 @error "Invalid list item: #{item.type}, expected FunctionCall or String"
@@ -102,15 +106,10 @@ class NomsuCompiler
         if type(text) == 'string' then text = {text}
         invocations = {}
         arg_names = {}
-        prev_arg_names = nil
         for _text in *text
             invocation = _text\gsub("'"," '")\gsub("%%%S+","%%")\gsub("%s+"," ")
             _arg_names = [arg for arg in _text\gmatch("%%(%S[^%s']*)")]
-            insert(invocations, invocation)
-            if prev_arg_names
-                if not utils.equivalent(utils.set(prev_arg_names), utils.set(_arg_names))
-                    @error("Conflicting argument names #{utils.repr(prev_arg_names)} and #{utils.repr(_arg_names)} for #{utils.repr(text)}")
-            else prev_arg_names = _arg_names
+            insert invocations, invocation
             arg_names[invocation] = _arg_names
         return invocations, arg_names
 
@@ -118,39 +117,18 @@ class NomsuCompiler
         if @debug
             @writeln("DEFINING MACRO: #{spec}#{src or ""}")
         invocations,arg_names = @get_invocations spec
+        for i=2,#invocations
+            if not utils.equivalent(utils.set(arg_names[invocations[1]]), utils.set(arg_names[invocations[i]]))
+                @error("Conflicting argument names #{utils.repr(invocations[1])} and #{utils.repr(invocations[i])} for #{utils.repr(spec)}")
         fn_info = {fn:lua_gen_fn, :arg_names, :invocations, :src, is_macro:true}
         for invocation in *invocations
             @defs[invocation] = fn_info
 
-    serialize: (obj)=>
-        switch type(obj)
-            when "function"
-                error("Function serialization is not yet implemented.")
-                "assert(load("..utils.repr(string.dump(obj)).."))"
-            when "table"
-                if utils.is_list obj
-                    "{#{table.concat([@serialize(i) for i in *obj], ", ")}}"
-                else
-                    "{#{table.concat(["[#{@serialize(k)}]= #{@serialize(v)}" for k,v in pairs(obj)], ", ")}}"
-            when "number"
-                utils.repr(obj)
-            when "string"
-                utils.repr(obj)
-            else
-                error "Serialization not implemented for: #{type(obj)}"
-
-    deserialize: (str)=>
-        lua_thunk, err = load("return (function(compiler,vars)
-        return "..str.."
-        end)")
-        if not lua_thunk
-            error("Failed to compile generated code:\n#{str}\n\n#{err}")
-        return (lua_thunk!)(self, {})
-
     parse: (str, filename)=>
         if @debug
             @writeln("PARSING:\n#{str}")
 
+        -- NOTE: this treats tabs as equivalent to 1 space
         indent_stack = {0}
         check_indent = (subject,end_pos,spaces)->
             if #spaces > indent_stack[#indent_stack]
@@ -357,8 +335,7 @@ class NomsuCompiler
                     return @@comma_separated_items("compiler:call(", args, ")")
 
             when "String"
-                unescaped = tree.value\gsub("\\(.)", ((c)-> STRING_ESCAPES[c] or c))
-                return utils.repr(unescaped)
+                return utils.repr(@@unescape_string(tree.value))
 
             when "Longstring"
                 concat_parts = {}
@@ -401,21 +378,21 @@ class NomsuCompiler
             else
                 @error("Unknown/unimplemented thingy: #{tree.type}")
 
+    @unescape_string: (str)=>
+        str\gsub("\\(.)", ((c)-> STRING_ESCAPES[c] or c))
+
     @comma_separated_items: (open, items, close)=>
-        utils.accumulate "\n", ->
-            buffer = open
-            so_far = 0
-            for i,item in ipairs(items)
-                if i < #items then item ..= ", "
-                if so_far + #item >= 80 and #buffer > 0
-                    coroutine.yield buffer
-                    so_far -= #buffer
-                    buffer = item
-                else
-                    so_far += #item
-                    buffer ..= item
-            buffer ..= close
-            coroutine.yield buffer
+        bits = {open}
+        so_far = 0
+        for i,item in ipairs(items)
+            if i < #items then item ..= ", "
+            insert bits, item
+            so_far += #item
+            if so_far >= 80
+                insert bits, "\n"
+                so_far = 0
+        insert bits, close
+        return table.concat(bits)
     
     fn_name_from_tree: (tree)=>
         assert(tree.type == "FunctionCall", "Attempt to get fn name from non-functioncall tree: #{tree.type}")
@@ -556,23 +533,14 @@ class NomsuCompiler
 
     initialize_core: =>
         -- Sets up some core functionality
-        as_lua_code = (str, vars)=>
-            switch str.type
-                when "String"
-                    return @tree_to_value(str, vars)
-                when "Longstring"
-                    return @tree_to_value(str, vars)
-                else
-                    return @tree_to_lua(str)
-
         @defmacro [[lua block %lua_code]], (vars, kind)=>
             if kind == "Expression" then error("Expected to be in statement.")
-            inner_vars = setmetatable({}, {__index:(_,key)-> "vars[#{utils.repr(key)}]"})
+            inner_vars = setmetatable({}, {__index:(_,key)-> error"vars[#{utils.repr(key)}]"})
             return "do\n"..@tree_to_value(vars.lua_code, inner_vars).."\nend", true
 
         @defmacro [[lua expr %lua_code]], (vars, kind)=>
             lua_code = vars.lua_code.value
-            inner_vars = setmetatable({}, {__index:(_,key)-> "vars[#{utils.repr(key)}]"})
+            inner_vars = setmetatable({}, {__index:(_,key)-> error"vars[#{utils.repr(key)}]"})
             return @tree_to_value(vars.lua_code, inner_vars)
 
         @def "require %filename", (vars)=>