16 files changed, 234 insertions, 48 deletions
diff --git a/Makefile b/Makefile
index b95b926..fd0ad0b 100644
--- a/Makefile
+++ b/Makefile
@@ -13,10 +13,12 @@ UNINSTALL_VERSION=
 
 MOON_FILES= code_obj.moon error_handling.moon files.moon nomsu.moon nomsu_compiler.moon \
 			syntax_tree.moon containers.moon bitops.moon parser.moon pretty_errors.moon \
-			text.moon nomsu_decompiler.moon nomsu_environment.moon bootstrap.moon
+			text.moon nomsu_decompiler.moon nomsu_environment.moon bootstrap.moon \
+			builtin_metatables.moon
 LUA_FILES= code_obj.lua error_handling.lua files.lua nomsu.lua nomsu_compiler.lua \
 		   syntax_tree.lua containers.lua bitops.lua parser.lua pretty_errors.lua \
-		   text.lua nomsu_decompiler.lua nomsu_environment.lua bootstrap.lua
+		   text.lua nomsu_decompiler.lua nomsu_environment.lua bootstrap.lua \
+		   builtin_metatables.lua
 CORE_NOM_FILES=$(shell cat lib/core/init.nom | sed -n 's;export "\(.*\)";lib/\1.nom;p') lib/core/init.nom
 CORE_LUA_FILES= $(patsubst %.nom,%.lua, $(CORE_NOM_FILES))
 COMPAT_NOM_FILES=$(wildcard lib/compatibility/*.nom)
diff --git a/bootstrap.lua b/bootstrap.lua
index 97a565d..31b03fc 100644
--- a/bootstrap.lua
+++ b/bootstrap.lua
@@ -124,9 +124,6 @@ local compile_actions = {
   ["is jit"] = function(self, _t, code)
     return LuaCode("jit")
   end,
-  ["Lua version"] = function(self, _t, code)
-    return LuaCode("_VERSION")
-  end,
   ["nomsu environment"] = function(self, _t)
     return LuaCode("_ENV")
   end,
diff --git a/bootstrap.moon b/bootstrap.moon
index d30e56b..6413205 100644
--- a/bootstrap.moon
+++ b/bootstrap.moon
@@ -98,7 +98,6 @@ compile_actions = {
         return LuaCode "TESTS[#{tostring(body.source)\as_lua!}] = ", test_text
 
     ["is jit"]: (_t, code)=> LuaCode("jit")
-    ["Lua version"]: (_t, code)=> LuaCode("_VERSION")
     ["nomsu environment"]: (_t)=> LuaCode("_ENV")
     ["nomsu environment name"]: (_t)=> LuaCode('"_ENV"')
     ["this file was run directly"]: (_t)=> LuaCode('WAS_RUN_DIRECTLY')
diff --git a/builtin_metatables.lua b/builtin_metatables.lua
new file mode 100644
index 0000000..e579e6c
--- /dev/null
+++ b/builtin_metatables.lua
@@ -0,0 +1,65 @@
+require("text")
+local number_mt = {
+  __type = "a Number",
+  as_lua = tostring,
+  as_nomsu = tostring,
+  as_text = tostring,
+  as_a_number = function(self)
+    return self
+  end,
+  rounded = function(self)
+    return math.floor(self + .5)
+  end,
+  rounded_down = math.floor,
+  rounded_up = math.ceil,
+  to_the_nearest = function(self, rounder)
+    return rounder * math.floor(self / rounder + 0.5)
+  end,
+  base16 = function(self)
+    return ("%X"):format(self)
+  end
+}
+number_mt.__index = number_mt
+debug.setmetatable(0, number_mt)
+local bool_mt = {
+  __type = "a Boolean",
+  as_lua = tostring,
+  as_nomsu = function(self)
+    return self and "yes" or "no"
+  end,
+  as_text = function(self)
+    return self and "yes" or "no"
+  end
+}
+bool_mt.__index = bool_mt
+debug.setmetatable(true, bool_mt)
+local fn_mt = {
+  __type = "an Action",
+  as_text = function(self)
+    return (tostring(self):gsub("function", "Action"))
+  end
+}
+fn_mt.__index = fn_mt
+debug.setmetatable((function() end), fn_mt)
+local co_mt = {
+  __type = "a Coroutine",
+  as_text = function(self)
+    return (tostring(self):gsub("thread", "Coroutine"))
+  end
+}
+co_mt.__index = co_mt
+debug.setmetatable(coroutine.create(function() end), co_mt)
+local nil_mt = {
+  __type = "Nil",
+  as_lua = function(self)
+    return "nil"
+  end,
+  as_nomsu = function(self)
+    return "nil"
+  end,
+  as_text = function(self)
+    return "nil"
+  end
+}
+nil_mt.__index = nil_mt
+return debug.setmetatable(nil, nil_mt)
diff --git a/builtin_metatables.moon b/builtin_metatables.moon
new file mode 100644
index 0000000..bc3ec7c
--- /dev/null
+++ b/builtin_metatables.moon
@@ -0,0 +1,44 @@
+-- This file defines some methods on Lua numbers
+require "text"
+
+number_mt =
+    __type: "a Number"
+    as_lua: tostring
+    as_nomsu: tostring
+    as_text: tostring
+    as_a_number: => @
+    rounded: => math.floor(@ + .5)
+    rounded_down: math.floor
+    rounded_up: math.ceil
+    to_the_nearest: (rounder)=> rounder * math.floor(@/rounder + 0.5)
+    base16: => ("%X")\format(@)
+number_mt.__index = number_mt
+debug.setmetatable 0, number_mt
+
+bool_mt =
+    __type: "a Boolean"
+    as_lua: tostring
+    as_nomsu: => @ and "yes" or "no"
+    as_text: => @ and "yes" or "no"
+bool_mt.__index = bool_mt
+debug.setmetatable true, bool_mt
+
+fn_mt =
+    __type: "an Action"
+    as_text: => (tostring(@)\gsub("function", "Action"))
+fn_mt.__index = fn_mt
+debug.setmetatable (->), fn_mt
+
+co_mt =
+    __type: "a Coroutine"
+    as_text: => (tostring(@)\gsub("thread", "Coroutine"))
+co_mt.__index = co_mt
+debug.setmetatable(coroutine.create(->), co_mt)
+
+nil_mt =
+    __type: "Nil"
+    as_lua: => "nil"
+    as_nomsu: => "nil"
+    as_text: => "nil"
+nil_mt.__index = nil_mt
+debug.setmetatable nil, nil_mt
diff --git a/lib/core/metaprogramming.nom b/lib/core/metaprogramming.nom
index da89665..096c62c 100644
--- a/lib/core/metaprogramming.nom
+++ b/lib/core/metaprogramming.nom
@@ -4,7 +4,7 @@
     functions to make that easier.
     
 lua> "NOMSU_CORE_VERSION = 15"
-lua> "NOMSU_LIB_VERSION = 8"
+lua> "NOMSU_LIB_VERSION = 9"
 lua> ("
     do
         local mangle_index = 0
@@ -93,8 +93,9 @@ lua> ("
         if \$body.type == "Text" then
             \$body = SyntaxTree{source=\$body.source, type="Action", "Lua", \$body}
         end
-        if not (\$action.type == "Action" or (\$action.type == "EscapedNomsu" and \$action[1]\
-    ...type == "Action")) then
+        if not (\$action.type == "Action" or
+                (\$action.type == "EscapedNomsu" and \$action[1].type == "Action") or
+                \$action.type == "MethodCall") then
             at_1_fail(\$action.source, "Compile error: "..
                 "This is neither an action nor an escaped action. "..
                 "Hint: This should probably be an action like:\\n"
@@ -182,7 +183,7 @@ test:
     lua> ("
         local lua = \(\($actions.1 means $body) as lua)
         local first_def = (\$actions[1].type == "MethodCall"
-            and LuaCode(\(nomsu environment):compile(\$actions[1][1]), ".", \$actions[1]:get_stub():as_lua_id())
+            and LuaCode(\(nomsu environment):compile(\$actions[1][1]), ".", \$actions[1][2]:get_stub():as_lua_id())
             or LuaCode(\$actions[1]:get_stub():as_lua_id()))
         local \$args = a_List(\$actions[1]:get_args())
         for i=2,#\$actions do
@@ -190,7 +191,7 @@ test:
             local \$alias_args = a_List(alias:get_args())
             lua:add("\\n")
             if alias.type == "MethodCall" then
-                lua:add(\(nomsu environment):compile(alias[1]), ".", alias:get_stub():as_lua_id())
+                lua:add(\(nomsu environment):compile(alias[1]), ".", alias[2]:get_stub():as_lua_id())
             else
                 lua:add(alias:get_stub():as_lua_id())
                 lua:add_free_vars({alias_name})
@@ -481,9 +482,9 @@ test:
     ")
 
 # Literals
-(yes) compiles to "true"
-(no) compiles to "false"
-[nothing, nil, null] all compile to "nil"
+(yes) compiles to "(true)"
+(no) compiles to "(false)"
+[nothing, nil, null] all compile to "(nil)"
 (Nomsu syntax version) compiles to "NOMSU_SYNTAX_VERSION"
 (Nomsu compiler version) compiles to "NOMSU_COMPILER_VERSION"
 (core version) compiles to "NOMSU_CORE_VERSION"
@@ -492,6 +493,16 @@ test:
 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+(at compilation $expr) compiles to:
+    lua> ("
+        local value = \(nomsu environment):run(\(\(return $expr)))
+        if lua_type_of(value) == 'table' or lua_type_of(value) == 'string' and value.as_lua then
+            return LuaCode(value:as_lua())
+        else
+            return LuaCode(tostring(value))
+        end
+    ")
+
 test:
     using compile rules:
         (yes) compiles to "3"
diff --git a/lib/core/operators.nom b/lib/core/operators.nom
index c2e6b57..4bdb5bc 100644
--- a/lib/core/operators.nom
+++ b/lib/core/operators.nom
@@ -159,6 +159,18 @@ test:
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 # Bitwise Operators
+# These can break if running the precompiled code from another Lua version:
+lua> ("
+    if \(at compilation $(LUA VERSION)) ~= \$(LUA VERSION) then
+        \(
+            fail ("
+                This code was precompiled with \(at compilation $(LUA VERSION)), but it is being run with \$(LUA VERSION)\
+                ... This will cause problems with bitwise operations.
+            ")
+        )
+    end
+")
+
 # TODO: implement OR, XOR, AND for multiple operands?
 test:
     assume ((~ (~ 5)) == 5)
@@ -170,22 +182,22 @@ test:
 
 # Lua 5.3 introduced bit operators like | and &. Use them when possible, otherwise
     fall back to bit.bor(), bit.band(), etc.
-lua> "if \((is jit) or ((Lua version) == "Lua 5.2")) then"
-[NOT $, ~ $] all compile to "bit.bnot(\($ as lua expr))"
+lua> "if \((is jit) or ($(LUA API) == "Lua 5.2")) then"
+[NOT $, ~ $] all compile to "Bit.bnot(\($ as lua expr))"
 [$x OR $y, $x | $y] all compile to
-    "bit.bor(\($x as lua expr), \($y as lua expr))"
+    "Bit.bor(\($x as lua expr), \($y as lua expr))"
 
 [$x XOR $y, $x ~ $y] all compile to
-    "bit.bxor(\($x as lua expr), \($y as lua expr))"
+    "Bit.bxor(\($x as lua expr), \($y as lua expr))"
 
 [$x AND $y, $x & $y] all compile to
-    "bit.band(\($x as lua expr), \($y as lua expr))"
+    "Bit.band(\($x as lua expr), \($y as lua expr))"
 
 [$x LSHIFT $shift, $x << $shift] all compile to
-    "bit.lshift(\($x as lua expr), \($shift as lua expr))"
+    "Bit.lshift(\($x as lua expr), \($shift as lua expr))"
 
 [$x RSHIFT $shift, $x >> $shift] all compile to
-    "bit.rshift(\($x as lua expr), \($shift as lua expr))"
+    "Bit.rshift(\($x as lua expr), \($shift as lua expr))"
 
 lua> "else"
 [NOT $, ~ $] all compile to "~(\($ as lua expr))"
diff --git a/lib/tools/test.nom b/lib/tools/test.nom
index 761ec55..945ce8c 100755
--- a/lib/tools/test.nom
+++ b/lib/tools/test.nom
@@ -41,16 +41,19 @@ command line program with $args:
                 if $args.v:
                     say "    \(yellow ($.test, with "\n" -> "\n    "))"
                 
-                try:
+                if $args.e:
                     $(test environment), run $.test
-                ..if it fails with $msg:
-                    $src = ($Source, from string $.source)
-                    $l1 = ($file, line number at $src.start)
-                    $l2 = ($file, line number at $src.stop)
-                    $failures, add ("
-                        \(yellow "\($src.filename):\($l1)-\$l2:")
-                        \(bright (red ($msg, indented)))
-                    ")
+                ..else:
+                    try:
+                        $(test environment), run $.test
+                    ..if it fails with $msg:
+                        $src = ($Source, from string $.source)
+                        $l1 = ($file, line number at $src.start)
+                        $l2 = ($file, line number at $src.stop)
+                        $failures, add ("
+                            \(yellow "\($src.filename):\($l1)-\$l2:")
+                            \(bright (red ($msg, indented)))
+                        ")
             
             if ($failures is empty):
                 if $args.v:
diff --git a/nomsu.lua b/nomsu.lua
index 814065d..2b7f5a6 100644
--- a/nomsu.lua
+++ b/nomsu.lua
@@ -45,6 +45,7 @@ do
   List, Dict = _obj_0.List, _obj_0.Dict
 end
 local Text = require('text')
+require('builtin_metatables')
 local sep = "\3"
 local parser = re.compile([[    args <- {| (flag %sep)*
          {:files: {|
diff --git a/nomsu.moon b/nomsu.moon
index f71f5e0..972be7f 100755
--- a/nomsu.moon
+++ b/nomsu.moon
@@ -43,6 +43,7 @@ Files = require "files"
 {:NomsuCode, :LuaCode, :Source} = require "code_obj"
 {:List, :Dict} = require 'containers'
 Text = require 'text'
+require 'builtin_metatables'
 
 sep = "\3"
 parser = re.compile([[
diff --git a/nomsu_compiler.lua b/nomsu_compiler.lua
index 7e562ea..096cdd1 100644
--- a/nomsu_compiler.lua
+++ b/nomsu_compiler.lua
@@ -52,6 +52,14 @@ local math_expression = re.compile([[ (([*/^+-] / [0-9]+) " ")* [*/^+-] !. ]])
 local MAX_LINE = 80
 local compile
 compile = function(self, tree)
+  if not (SyntaxTree:is_instance(tree)) then
+    do
+      local as_lua = tree.as_lua
+      if as_lua then
+        return as_lua(tree)
+      end
+    end
+  end
   local _exp_0 = tree.type
   if "Action" == _exp_0 then
     local stub = tree.stub
@@ -119,6 +127,24 @@ compile = function(self, tree)
     lua:add(")")
     return lua
   elseif "MethodCall" == _exp_0 then
+    local stub = tree:get_stub()
+    local compile_action = self.COMPILE_RULES[stub]
+    if compile_action then
+      local args = tree:get_args()
+      local ret = compile_action(self, tree, unpack(args))
+      if ret == nil then
+        local info = debug.getinfo(compile_action, "S")
+        local filename = Source:from_string(info.source).filename
+        fail_at(tree, ("Compile error: The compile-time method here (" .. tostring(stub) .. ") failed to return any value. " .. "Hint: Look at the implementation of (" .. tostring(stub) .. ") in " .. tostring(filename) .. ":" .. tostring(info.linedefined) .. " " .. "and make sure it's returning something."))
+      end
+      if not (SyntaxTree:is_instance(ret)) then
+        ret.source = ret.source or tree.source
+        return ret
+      end
+      if ret ~= tree then
+        return self:compile(ret)
+      end
+    end
     local lua = LuaCode:from(tree.source)
     local target_lua = self:compile(tree[1])
     local target_text = target_lua:text()
diff --git a/nomsu_compiler.moon b/nomsu_compiler.moon
index 1b3e952..068173e 100644
--- a/nomsu_compiler.moon
+++ b/nomsu_compiler.moon
@@ -62,8 +62,6 @@ compile = (tree)=>
 
             if compile_action
                 args = [arg for arg in *tree when type(arg) != "string"]
-                -- Force Lua to avoid tail call optimization for debugging purposes
-                -- TODO: use tail call?
                 ret = compile_action(@, tree, unpack(args))
                 if ret == nil
                     info = debug.getinfo(compile_action, "S")
@@ -92,6 +90,24 @@ compile = (tree)=>
             return lua
 
         when "MethodCall"
+            stub = tree\get_stub!
+            compile_action = @COMPILE_RULES[stub]
+            if compile_action
+                args = tree\get_args!
+                ret = compile_action(@, tree, unpack(args))
+                if ret == nil
+                    info = debug.getinfo(compile_action, "S")
+                    filename = Source\from_string(info.source).filename
+                    fail_at tree,
+                        ("Compile error: The compile-time method here (#{stub}) failed to return any value. "..
+                        "Hint: Look at the implementation of (#{stub}) in #{filename}:#{info.linedefined} "..
+                        "and make sure it's returning something.")
+                unless SyntaxTree\is_instance(ret)
+                    ret.source or= tree.source
+                    return ret
+                if ret != tree
+                    return @compile(ret)
+
             lua = LuaCode\from tree.source
             target_lua = @compile tree[1]
             target_text = target_lua\text!
diff --git a/nomsu_environment.lua b/nomsu_environment.lua
index 0fdf1cf..e359257 100644
--- a/nomsu_environment.lua
+++ b/nomsu_environment.lua
@@ -131,7 +131,9 @@ nomsu_environment = Importer({
   ipairs = ipairs,
   jit = jit,
   _VERSION = _VERSION,
-  bit = (jit or _VERSION == "Lua 5.2") and require('bitops') or nil,
+  LUA_VERSION = (jit and jit.version or _VERSION),
+  LUA_API = _VERSION,
+  Bit = (jit or _VERSION == "Lua 5.2") and require('bitops') or nil,
   a_List = List,
   a_Dict = Dict,
   Text = Text,
diff --git a/nomsu_environment.moon b/nomsu_environment.moon
index 8cd3228..1deac6f 100644
--- a/nomsu_environment.moon
+++ b/nomsu_environment.moon
@@ -58,8 +58,8 @@ nomsu_environment = Importer{
     :error, :package, :os, :require, :tonumber, :tostring, :string, :xpcall,
     :print, :loadfile, :rawset, :_VERSION, :collectgarbage, :rawget, :rawlen,
     :table, :assert, :dofile, :loadstring, lua_type_of:type, :select, :math, :io, :load,
-    :pairs, :ipairs, :jit, :_VERSION
-    bit: (jit or _VERSION == "Lua 5.2") and require('bitops') or nil
+    :pairs, :ipairs, :jit, :_VERSION, LUA_VERSION: (jit and jit.version or _VERSION),
+    LUA_API: _VERSION, Bit: (jit or _VERSION == "Lua 5.2") and require('bitops') or nil
     -- Nomsu types:
     a_List:List, a_Dict:Dict, Text:Text,
     -- Utilities and misc.
diff --git a/syntax_tree.lua b/syntax_tree.lua
index b9668e7..b7b7f83 100644
--- a/syntax_tree.lua
+++ b/syntax_tree.lua
@@ -147,13 +147,14 @@ do
       assert(self.type == "Action" or self.type == "MethodCall", "Only actions and method calls have arguments")
       local args = { }
       if self.type == "MethodCall" then
-        assert(#self == 2, "Can't get arguments for multiple method calls at once.")
         args[1] = self[1]
-        local _list_0 = self[2]
-        for _index_0 = 1, #_list_0 do
-          local tok = _list_0[_index_0]
-          if type(tok) ~= 'string' then
-            args[#args + 1] = tok
+        for i = 2, #self do
+          local _list_0 = self[i]
+          for _index_0 = 1, #_list_0 do
+            local tok = _list_0[_index_0]
+            if type(tok) ~= 'string' then
+              args[#args + 1] = tok
+            end
           end
         end
       else
@@ -168,8 +169,15 @@ do
     end,
     get_stub = function(self)
       if self.type == "MethodCall" then
-        assert(#self == 2, "Can't get the stubs of multiple method calls at once.")
-        return self[2]:get_stub()
+        return "0, " .. table.concat((function()
+          local _accum_0 = { }
+          local _len_0 = 1
+          for i = 2, #self do
+            _accum_0[_len_0] = self[i]:get_stub()
+            _len_0 = _len_0 + 1
+          end
+          return _accum_0
+        end)(), "; ")
       end
       local stub_bits = { }
       local arg_i = 1
diff --git a/syntax_tree.moon b/syntax_tree.moon
index eb9c87c..278e22b 100644
--- a/syntax_tree.moon
+++ b/syntax_tree.moon
@@ -72,10 +72,10 @@ class SyntaxTree
         assert(@type == "Action" or @type == "MethodCall", "Only actions and method calls have arguments")
         args = {}
         if @type == "MethodCall"
-            assert(#@ == 2, "Can't get arguments for multiple method calls at once.")
             args[1] = @[1]
-            for tok in *@[2]
-                if type(tok) != 'string' then args[#args+1] = tok
+            for i=2,#@
+                for tok in *@[i]
+                    if type(tok) != 'string' then args[#args+1] = tok
         else
             for tok in *@
                 if type(tok) != 'string' then args[#args+1] = tok
@@ -83,8 +83,7 @@ class SyntaxTree
 
     get_stub: =>
         if @type == "MethodCall"
-            assert(#@ == 2, "Can't get the stubs of multiple method calls at once.")
-            return @[2]\get_stub!
+            return "0, "..table.concat([@[i]\get_stub! for i=2,#@], "; ")
         stub_bits = {}
         arg_i = 1
         for a in *@