From 79d4bd5125de7ff220fbf8a8a5493d437ed16963 Mon Sep 17 00:00:00 2001
From: Bruce Hill <bitbucket@bruce-hill.com>
Date: Tue, 18 Sep 2018 19:48:58 -0700
Subject: [PATCH] Got rid of repr() use and replaced with :as_lua() or
 :as_nomsu() in as many places as possible.

---
 code_obj.lua             | 20 ++++-----
 code_obj.moon            | 15 ++++---
 containers.lua           | 90 ++++++++++++++++++++++++++++++++++++++--
 containers.moon          | 30 ++++++++++++--
 core/collections.nom     |  2 +
 core/metaprogramming.nom | 24 ++++++-----
 lib/object.nom           | 10 ++++-
 nomsu.lua                |  8 ++--
 nomsu.moon               |  6 ++-
 nomsu_compiler.lua       | 39 ++++++++++-------
 nomsu_compiler.moon      | 37 ++++++++++-------
 parser.lua               |  2 -
 parser.moon              |  1 -
 string2.lua              | 18 ++++++++
 string2.moon             | 14 +++++++
 syntax_tree.lua          | 58 +++++++++++++++++++++++---
 syntax_tree.moon         | 23 ++++++++--
 17 files changed, 312 insertions(+), 85 deletions(-)

diff --git a/code_obj.lua b/code_obj.lua
index d51d63f..5be92e6 100644
--- a/code_obj.lua
+++ b/code_obj.lua
@@ -3,8 +3,6 @@ do
   local _obj_0 = table
   insert, remove, concat = _obj_0.insert, _obj_0.remove, _obj_0.concat
 end
-local repr
-repr = require('utils').repr
 local unpack = unpack or table.unpack
 local LuaCode, NomsuCode, Source
 do
@@ -13,8 +11,8 @@ do
     __tostring = function(self)
       return "@" .. tostring(self.filename) .. "[" .. tostring(self.start) .. tostring(self.stop and ':' .. self.stop or '') .. "]"
     end,
-    __repr = function(self)
-      return "Source(" .. tostring(repr(self.filename)) .. ", " .. tostring(self.start) .. tostring(self.stop and ', ' .. self.stop or '') .. ")"
+    as_lua = function(self)
+      return "Source(" .. tostring(self.filename:as_lua()) .. ", " .. tostring(self.start) .. tostring(self.stop and ', ' .. self.stop or '') .. ")"
     end,
     __eq = function(self, other)
       return getmetatable(self) == getmetatable(other) and self.filename == other.filename and self.start == other.start and self.stop == other.stop
@@ -108,16 +106,16 @@ do
       end
       return self.__str
     end,
-    __repr = function(self)
+    as_lua = function(self)
       return tostring(self.__class.__name) .. "(" .. tostring(concat({
-        repr(tostring(self.source)),
+        tostring(self.source):as_lua(),
         unpack((function()
           local _accum_0 = { }
           local _len_0 = 1
           local _list_0 = self.bits
           for _index_0 = 1, #_list_0 do
             local b = _list_0[_index_0]
-            _accum_0[_len_0] = repr(b)
+            _accum_0[_len_0] = b:as_lua()
             _len_0 = _len_0 + 1
           end
           return _accum_0
@@ -158,7 +156,7 @@ do
             b.dirty = error
           end
           if type(b) ~= 'string' and not (type(b) == 'table' and b.is_code) then
-            b = repr(b)
+            b = b:as_lua()
           end
           bits[#bits + 1] = b
           _continue_0 = true
@@ -236,7 +234,7 @@ do
           b.dirty = error
         end
         if type(b) ~= 'string' and not (type(b) == 'table' and b.is_code) then
-          b = repr(b)
+          b = b:as_lua()
         end
         bits[i] = b
       end
@@ -276,7 +274,7 @@ do
   local _parent_0 = Code
   local _base_0 = {
     __tostring = Code.__tostring,
-    __repr = Code.__repr,
+    as_lua = Code.as_lua,
     __len = Code.__len,
     add_free_vars = function(self, vars)
       if not (#vars > 0) then
@@ -469,7 +467,7 @@ do
   local _parent_0 = Code
   local _base_0 = {
     __tostring = Code.__tostring,
-    __repr = Code.__repr,
+    as_lua = Code.as_lua,
     __len = Code.__len
   }
   _base_0.__index = _base_0
diff --git a/code_obj.moon b/code_obj.moon
index bd53c5b..4e70784 100644
--- a/code_obj.moon
+++ b/code_obj.moon
@@ -2,7 +2,6 @@
 -- build up generated code, while keeping track of where it came from, and managing
 -- indentation levels.
 {:insert, :remove, :concat} = table
-{:repr} = require 'utils'
 unpack or= table.unpack
 local LuaCode, NomsuCode, Source
 
@@ -19,7 +18,7 @@ class Source
 
     __tostring: => "@#{@filename}[#{@start}#{@stop and ':'..@stop or ''}]"
 
-    __repr: => "Source(#{repr @filename}, #{@start}#{@stop and ', '..@stop or ''})"
+    as_lua: => "Source(#{@filename\as_lua!}, #{@start}#{@stop and ', '..@stop or ''})"
     
     __eq: (other)=>
         getmetatable(@) == getmetatable(other) and @filename == other.filename and @start == other.start and @stop == other.stop
@@ -67,8 +66,8 @@ class Code
             @__str = concat(buff, "")
         return @__str
 
-    __repr: =>
-        "#{@__class.__name}(#{concat {repr(tostring(@source)), unpack([repr(b) for b in *@bits])}, ", "})"
+    as_lua: =>
+        "#{@__class.__name}(#{concat {tostring(@source)\as_lua!, unpack([b\as_lua! for b in *@bits])}, ", "})"
 
     __len: => #tostring(@)
     
@@ -93,7 +92,7 @@ class Code
             if b == '' then continue
             b.dirty = error if b.is_code
             if type(b) != 'string' and not (type(b) == 'table' and b.is_code)
-                b = repr(b)
+                b = b\as_lua!
             bits[#bits+1] = b
         @dirty!
     
@@ -148,7 +147,7 @@ class Code
             b = select(i, ...)
             b.dirty = error if b.is_code
             if type(b) != 'string' and not (type(b) == 'table' and b.is_code)
-                b = repr(b)
+                b = b\as_lua!
             bits[i] = b
         @dirty!
 
@@ -158,7 +157,7 @@ class Code
 
 class LuaCode extends Code
     __tostring: Code.__tostring
-    __repr: Code.__repr
+    as_lua: Code.as_lua
     __len: Code.__len
     new: (...)=>
         super ...
@@ -253,7 +252,7 @@ class LuaCode extends Code
 
 class NomsuCode extends Code
     __tostring: Code.__tostring
-    __repr: Code.__repr
+    as_lua: Code.as_lua
     __len: Code.__len
 
 Code.__base.append_1 = assert Code.__base.append
diff --git a/containers.lua b/containers.lua
index 1b3fd94..a7819ec 100644
--- a/containers.lua
+++ b/containers.lua
@@ -3,14 +3,50 @@ do
   local _obj_0 = table
   insert, remove, concat = _obj_0.insert, _obj_0.remove, _obj_0.concat
 end
-local repr, stringify, equivalent, nth_to_last, size
+local equivalent, nth_to_last, size
 do
   local _obj_0 = require('utils')
-  repr, stringify, equivalent, nth_to_last, size = _obj_0.repr, _obj_0.stringify, _obj_0.equivalent, _obj_0.nth_to_last, _obj_0.size
+  equivalent, nth_to_last, size = _obj_0.equivalent, _obj_0.nth_to_last, _obj_0.size
 end
 local lpeg = require('lpeg')
 local re = require('re')
 local List, Dict
+local as_nomsu
+as_nomsu = function(self)
+  if type(self) == 'number' then
+    return tostring(self)
+  end
+  do
+    local mt = getmetatable(self)
+    if mt then
+      do
+        local _as_nomsu = mt.as_nomsu
+        if _as_nomsu then
+          return _as_nomsu(self)
+        end
+      end
+    end
+  end
+  return error("Not supported: " .. tostring(self))
+end
+local as_lua
+as_lua = function(self)
+  if type(self) == 'number' then
+    return tostring(self)
+  end
+  do
+    local mt = getmetatable(self)
+    if mt then
+      do
+        local _as_lua = mt.as_lua
+        if _as_lua then
+          return _as_lua(self)
+        end
+      end
+    end
+  end
+  return error("Not supported: " .. tostring(self))
+end
 local _list_mt = {
   __eq = equivalent,
   __tostring = function(self)
@@ -19,12 +55,36 @@ local _list_mt = {
       local _len_0 = 1
       for _index_0 = 1, #self do
         local b = self[_index_0]
-        _accum_0[_len_0] = repr(b)
+        _accum_0[_len_0] = tostring(b)
         _len_0 = _len_0 + 1
       end
       return _accum_0
     end)(), ", ") .. "]"
   end,
+  as_nomsu = function(self)
+    return "[" .. concat((function()
+      local _accum_0 = { }
+      local _len_0 = 1
+      for _index_0 = 1, #self do
+        local b = self[_index_0]
+        _accum_0[_len_0] = as_nomsu(b)
+        _len_0 = _len_0 + 1
+      end
+      return _accum_0
+    end)(), ", ") .. "]"
+  end,
+  as_lua = function(self)
+    return "_List{" .. concat((function()
+      local _accum_0 = { }
+      local _len_0 = 1
+      for _index_0 = 1, #self do
+        local b = self[_index_0]
+        _accum_0[_len_0] = as_lua(b)
+        _len_0 = _len_0 + 1
+      end
+      return _accum_0
+    end)(), ", ") .. "}"
+  end,
   __lt = function(self, other)
     assert(type(self) == 'table' and type(other) == 'table', "Incompatible types for comparison")
     for i = 1, math.max(#self, #other) do
@@ -162,7 +222,29 @@ local _dict_mt = {
       local _accum_0 = { }
       local _len_0 = 1
       for k, v in pairs(self) do
-        _accum_0[_len_0] = tostring(repr(k)) .. ": " .. tostring(repr(v))
+        _accum_0[_len_0] = tostring(tostring(k)) .. ": " .. tostring(tostring(v))
+        _len_0 = _len_0 + 1
+      end
+      return _accum_0
+    end)(), ", ") .. "}"
+  end,
+  as_nomsu = function(self)
+    return "{" .. concat((function()
+      local _accum_0 = { }
+      local _len_0 = 1
+      for k, v in pairs(self) do
+        _accum_0[_len_0] = tostring(as_nomsu(k)) .. ": " .. tostring(as_nomsu(v))
+        _len_0 = _len_0 + 1
+      end
+      return _accum_0
+    end)(), ", ") .. "}"
+  end,
+  as_lua = function(self)
+    return "_Dict{" .. concat((function()
+      local _accum_0 = { }
+      local _len_0 = 1
+      for k, v in pairs(self) do
+        _accum_0[_len_0] = "[ " .. tostring(as_lua(k)) .. "]= " .. tostring(as_lua(v))
         _len_0 = _len_0 + 1
       end
       return _accum_0
diff --git a/containers.moon b/containers.moon
index eaf007a..70a9f70 100644
--- a/containers.moon
+++ b/containers.moon
@@ -1,19 +1,39 @@
 -- This file contains container classes, i.e. Lists, Dicts, and Sets
 
 {:insert,:remove,:concat} = table
-{:repr, :stringify, :equivalent, :nth_to_last, :size} = require 'utils'
+{:equivalent, :nth_to_last, :size} = require 'utils'
 lpeg = require 'lpeg'
 re = require 're'
 
 local List, Dict
 
+as_nomsu = =>
+    if type(@) == 'number'
+        return tostring(@)
+    if mt = getmetatable(@)
+        if _as_nomsu = mt.as_nomsu
+            return _as_nomsu(@)
+    error("Not supported: #{@}")
+
+as_lua = =>
+    if type(@) == 'number'
+        return tostring(@)
+    if mt = getmetatable(@)
+        if _as_lua = mt.as_lua
+            return _as_lua(@)
+    error("Not supported: #{@}")
+
 -- List and Dict classes to provide basic equality/tostring functionality for the tables
 -- used in Nomsu. This way, they retain a notion of whether they were originally lists or dicts.
 _list_mt =
     __eq:equivalent
     -- Could consider adding a __newindex to enforce list-ness, but would hurt performance
     __tostring: =>
-        "["..concat([repr(b) for b in *@], ", ").."]"
+        "["..concat([tostring(b) for b in *@], ", ").."]"
+    as_nomsu: =>
+        "["..concat([as_nomsu(b) for b in *@], ", ").."]"
+    as_lua: =>
+        "_List{"..concat([as_lua(b) for b in *@], ", ").."}"
     __lt: (other)=>
         assert type(@) == 'table' and type(other) == 'table', "Incompatible types for comparison"
         for i=1,math.max(#@, #other)
@@ -74,7 +94,11 @@ _dict_mt =
     __eq:equivalent
     __len:size
     __tostring: =>
-        "{"..concat(["#{repr(k)}: #{repr(v)}" for k,v in pairs @], ", ").."}"
+        "{"..concat(["#{tostring(k)}: #{tostring(v)}" for k,v in pairs @], ", ").."}"
+    as_nomsu: =>
+        "{"..concat(["#{as_nomsu(k)}: #{as_nomsu(v)}" for k,v in pairs @], ", ").."}"
+    as_lua: =>
+        "_Dict{"..concat(["[ #{as_lua(k)}]= #{as_lua(v)}" for k,v in pairs @], ", ").."}"
     __ipairs: => walk_items, {table:@, key:nil}, 0
     __band: (other)=>
         Dict{k,v for k,v in pairs(@) when other[k] != nil}
diff --git a/core/collections.nom b/core/collections.nom
index 8dbc79d..3877d31 100644
--- a/core/collections.nom
+++ b/core/collections.nom
@@ -149,6 +149,8 @@ test:
     assume ("\%t" == "XXX")
 compile [set %dict 's metatable to %metatable] to (..)
     Lua "setmetatable(\(%dict as lua expr), \(%metatable as lua expr));"
+compile [%'s metatable, %' metatable] to (..)
+    Lua value "getmetatable(\(% as lua expr))"
 
 test:
     assume (({} with fallback % -> (% + 1)).10 == 11)
diff --git a/core/metaprogramming.nom b/core/metaprogramming.nom
index c50f783..51831ec 100644
--- a/core/metaprogramming.nom
+++ b/core/metaprogramming.nom
@@ -34,7 +34,7 @@ lua> "\
 
 lua> "\
     ..COMPILE_ACTIONS["compile as 1"] = function(nomsu, tree, \%action)
-        local lua = LuaCode.Value(tree.source, "COMPILE_ACTIONS[", repr(\%action.stub), "](")
+        local lua = LuaCode.Value(tree.source, "COMPILE_ACTIONS[", \%action.stub:as_lua(), "](")
         local lua_args = table.map(\%action:get_args(), function(a) return nomsu:compile(a) end)
         table.insert(lua_args, 1, "nomsu")
         table.insert(lua_args, 2, "tree")
@@ -66,19 +66,19 @@ lua> "\
     ..COMPILE_ACTIONS["compile 1 to 2"] = function(nomsu, tree, \%actions, \%body)
         local \%args = {"nomsu", "tree", unpack(table.map(\%actions[1]:get_args(), function(a) return tostring(nomsu:compile(\
     ..a)) end))}
-        local lua = LuaCode(tree.source, "COMPILE_ACTIONS[", repr(\%actions[1].stub),
+        local lua = LuaCode(tree.source, "COMPILE_ACTIONS[", \%actions[1].stub:as_lua(),
             "] = ", \(compile as (%args -> %body)))
         for i=2,#\%actions do
             local alias = \%actions[i]
             local \%alias_args = {"nomsu", "tree", unpack(table.map(alias:get_args(), function(a) return tostring(nomsu:compile(\
     ..a)) end))}
-            lua:append("\\nCOMPILE_ACTIONS[", repr(alias.stub), "] = ")
+            lua:append("\\nCOMPILE_ACTIONS[", alias.stub:as_lua(), "] = ")
             if utils.equivalent(\%args, \%alias_args) then
-                lua:append("COMPILE_ACTIONS[", repr(\%actions[1].stub), "]")
+                lua:append("COMPILE_ACTIONS[", \%actions[1].stub:as_lua(), "]")
             else
                 lua:append("function(")
                 lua:concat_append(\%alias_args, ", ")
-                lua:append(")\\n    return COMPILE_ACTIONS[", repr(\%actions[1].stub), "](")
+                lua:append(")\\n    return COMPILE_ACTIONS[", \%actions[1].stub:as_lua(), "](")
                 lua:concat_append(\%args, ", ")
                 lua:append(")\\nend")
             end
@@ -173,7 +173,7 @@ compile [parse %actions as %body] to (..)
                 if replacements[t[1]] then
                     return replacements[t[1]]
                 else
-                    return t.type.."{mangle("..repr(t[1]).."), source="..repr(tostring(t.source)).."}"
+                    return t.type.."{mangle("..t[1]:as_lua().."), source="..tostring(t.source):as_lua().."}"
                 end
             elseif AST.is_syntax_tree(t) then
                 local ret = {}
@@ -183,7 +183,7 @@ compile [parse %actions as %body] to (..)
                         ret[#ret+1] = make_tree(t[i])
                         i = i + 1
                     elseif k == "source" then
-                        ret[#ret+1] = k.."= "..repr(tostring(v))
+                        ret[#ret+1] = k.."= "..tostring(v):as_lua()
                     elseif type(k) == 'string' and k:match("[_a-zA-Z][_a-zA-Z0-9]*") then
                         ret[#ret+1] = k.."= "..make_tree(v)
                     else
@@ -191,8 +191,10 @@ compile [parse %actions as %body] to (..)
                     end
                 end
                 return t.type.."{"..table.concat(ret, ", ").."}"
+            elseif type(t) == 'number' then
+                return tostring(t)
             else
-                return repr(t)
+                return t:as_lua()
             end
         end
         local \%new_body = LuaCode(\%body.source,
@@ -257,7 +259,7 @@ action [%tree with vars %replacements] (..)
 
 compile [tree %tree with vars %replacements] to (..)
     Lua value "\
-        ..\(=lua "repr(\%tree)"):map(function(t)
+        ..\(=lua "(\%tree):as_lua()"):map(function(t)
             if t.type == "Var" then
                 return \(%replacements as lua expr)[t[1]]
             end
@@ -312,7 +314,7 @@ test:
                 ..one
                 "two""
         ..== "\"one\\n\\\"two\\\"\""
-compile [quote %s] to (Lua value "repr(\(%s as lua expr))")
+compile [quote %s] to (Lua value "tostring(\(%s as lua expr)):as_lua()")
 
 test:
     assume ((type of {}) == "table") or barf "type of failed."
@@ -340,7 +342,7 @@ test:
 compile [run %nomsu_code] to (..)
     Lua value "\
         ..nomsu:run(NomsuCode(\(..)
-            =lua "repr(tostring(\(%nomsu_code.source)))"
+            =lua "tostring(\(%nomsu_code.source)):as_lua()"
         .., \(%nomsu_code as lua expr)))"
 
 test:
diff --git a/lib/object.nom b/lib/object.nom
index b49b8f2..600ecf6 100644
--- a/lib/object.nom
+++ b/lib/object.nom
@@ -46,7 +46,7 @@ compile [my action %actions %body] to:
     lua> "\
         ..local fn_name = \%actions[1].stub:as_lua_id()
         local \%args = table.map(\%actions[1]:get_args(), function(a) return tostring(nomsu:compile(a)) end)
-        table.insert(\%args, \(\%me as lua id))
+        table.insert(\%args, 1, \(\%me as lua id))
         local lua = LuaCode(tree.source, "class.", fn_name, " = ", \(..)
             compile as (%args -> %body)
         ..)
@@ -54,7 +54,7 @@ compile [my action %actions %body] to:
             local alias = \%actions[i]
             local alias_name = alias.stub:as_lua_id()
             local \%alias_args = table.map(alias:get_args(), function(a) return tostring(nomsu:compile(a)) end)
-            table.insert(\%alias_args, \(\%me as lua id))
+            table.insert(\%alias_args, 1, \(\%me as lua id))
             lua:append("\\nclass.", alias_name, " = ")
             if utils.equivalent(\%args, \%alias_args) then
                 lua:append("class.", fn_name)
@@ -110,3 +110,9 @@ compile [object %classname extends %parent %class_body] to:
 
 parse [object %classname %class_body] as (..)
     object %classname extends (nil) %class_body
+
+parse [%obj is a %class] as (..)
+    all of [..]
+        (type of %obj) == "table"
+        %obj's metatable
+        (%obj's metatable).__index == %class
diff --git a/nomsu.lua b/nomsu.lua
index 3d78dd1..fa6a6ce 100644
--- a/nomsu.lua
+++ b/nomsu.lua
@@ -91,8 +91,6 @@ do
   local _obj_0 = require("code_obj")
   NomsuCode, LuaCode, Source = _obj_0.NomsuCode, _obj_0.LuaCode, _obj_0.Source
 end
-local repr
-repr = require("utils").repr
 if not arg or debug.getinfo(2).func == require then
   return NomsuCompiler
 end
@@ -324,7 +322,11 @@ say "\
       local ret
       ok, ret = xpcall(nomsu.run, err_hand, nomsu, buff, Source(pseudo_filename, 1, #buff))
       if ok and ret ~= nil then
-        print("= " .. repr(ret))
+        if type(ret) == 'number' then
+          print("= " .. tostring(ret))
+        else
+          print("= " .. tostring(ret:as_nomsu()))
+        end
       elseif not ok then
         Errhand.print_error(ret)
       end
diff --git a/nomsu.moon b/nomsu.moon
index 382a5b5..1ab9637 100755
--- a/nomsu.moon
+++ b/nomsu.moon
@@ -48,7 +48,6 @@ Files = require "files"
 Errhand = require "error_handling"
 NomsuCompiler = require "nomsu_compiler"
 {:NomsuCode, :LuaCode, :Source} = require "code_obj"
-{:repr} = require "utils"
 
 -- If this file was reached via require(), then just return the Nomsu compiler
 if not arg or debug.getinfo(2).func == require
@@ -222,7 +221,10 @@ say "\
                 Errhand.print_error error_message
             ok, ret = xpcall(nomsu.run, err_hand, nomsu, buff, Source(pseudo_filename, 1, #buff))
             if ok and ret != nil
-                print "= "..repr(ret)
+                if type(ret) == 'number'
+                    print "= #{ret}"
+                else
+                    print "= #{ret\as_nomsu!}"
             elseif not ok
                 Errhand.print_error ret
 
diff --git a/nomsu_compiler.lua b/nomsu_compiler.lua
index 2e286b7..89d247a 100644
--- a/nomsu_compiler.lua
+++ b/nomsu_compiler.lua
@@ -4,8 +4,8 @@ R, P, S = lpeg.R, lpeg.P, lpeg.S
 local re = require('re')
 local utils = require('utils')
 local Files = require('files')
-local repr, stringify, equivalent
-repr, stringify, equivalent = utils.repr, utils.stringify, utils.equivalent
+local stringify, equivalent
+stringify, equivalent = utils.stringify, utils.equivalent
 local List, Dict, Text
 do
   local _obj_0 = require('containers')
@@ -193,7 +193,6 @@ do
     ipairs = ipairs,
     _List = List,
     _Dict = Dict,
-    repr = repr,
     stringify = stringify,
     utils = utils,
     lpeg = lpeg,
@@ -385,7 +384,7 @@ do
   add_lua_string_bits = function(self, val_or_stmt, code)
     local cls_str = val_or_stmt == "value" and "LuaCode.Value(" or "LuaCode("
     if code.type ~= "Text" then
-      return LuaCode.Value(code.source, cls_str, repr(tostring(code.source)), ", ", self:compile(code), ")")
+      return LuaCode.Value(code.source, cls_str, tostring(code.source):as_lua(), ", ", self:compile(code), ")")
     end
     local add_bit_lua
     add_bit_lua = function(lua, bit_lua)
@@ -395,11 +394,11 @@ do
     end
     local operate_on_text
     operate_on_text = function(text)
-      local lua = LuaCode.Value(text.source, cls_str, repr(tostring(text.source)))
+      local lua = LuaCode.Value(text.source, cls_str, tostring(text.source):as_lua())
       for _index_0 = 1, #text do
         local bit = text[_index_0]
         if type(bit) == "string" then
-          add_bit_lua(lua, repr(bit))
+          add_bit_lua(lua, bit:as_lua())
         elseif bit.type == "Text" then
           add_bit_lua(lua, operate_on_text(bit))
         else
@@ -480,13 +479,13 @@ do
         end
         return _accum_0
       end)(), "\n")
-      return LuaCode(tree.source, "TESTS[" .. tostring(repr(tostring(tree.source))) .. "] = ", repr(test_str))
+      return LuaCode(tree.source, "TESTS[" .. tostring(tostring(tree.source):as_lua()) .. "] = ", test_str:as_lua())
     end,
     ["is jit"] = function(self, tree, code)
       return LuaCode.Value(tree.source, jit and "true" or "false")
     end,
     ["Lua version"] = function(self, tree, code)
-      return LuaCode.Value(tree.source, repr(_VERSION))
+      return LuaCode.Value(tree.source, _VERSION:as_lua())
     end,
     __parent = setmetatable({ }, {
       __index = function(self, key)
@@ -744,9 +743,9 @@ do
             if tok.type == "Block" then
               self:compile_error(tok, "Can't compile action (" .. tostring(stub) .. ") with a Block as an argument.", "Maybe there should be a compile-time action with that name that isn't being found?")
             elseif tok.type == "Action" then
-              self:compile_error(tok, "Can't use this as an argument to (" .. tostring(stub) .. "), since it's not an expression, it produces: " .. tostring(repr(arg_lua)), "Check the implementation of (" .. tostring(tok.stub) .. ") to see if it is actually meant to produce an expression.")
+              self:compile_error(tok, "Can't use this as an argument to (" .. tostring(stub) .. "), since it's not an expression, it produces: " .. tostring(tostring(arg_lua)), "Check the implementation of (" .. tostring(tok.stub) .. ") to see if it is actually meant to produce an expression.")
             else
-              self:compile_error(tok, "Can't use this as an argument to (" .. tostring(stub) .. "), since it's not an expression, it produces: " .. tostring(repr(arg_lua)))
+              self:compile_error(tok, "Can't use this as an argument to (" .. tostring(stub) .. "), since it's not an expression, it produces: " .. tostring(tostring(arg_lua)))
             end
           end
           insert(args, arg_lua)
@@ -762,6 +761,16 @@ do
     elseif "EscapedNomsu" == _exp_0 then
       local lua = LuaCode.Value(tree.source, tree[1].type, "{")
       local needs_comma, i = false, 1
+      local as_lua
+      as_lua = function(x)
+        if type(x) == 'number' then
+          return tostring(x)
+        elseif AST.is_syntax_tree(x) then
+          return self:compile(x, compile_actions)
+        else
+          return x:as_lua()
+        end
+      end
       for k, v in pairs(AST.is_syntax_tree(tree[1], "EscapedNomsu") and tree or tree[1]) do
         if needs_comma then
           lua:append(", ")
@@ -773,12 +782,12 @@ do
         elseif type(k) == 'string' and match(k, "[_a-zA-Z][_a-zA-Z0-9]*") then
           lua:append(k, "= ")
         else
-          lua:append("[", (AST.is_syntax_tree(k) and self:compile(k, compile_actions) or repr(k)), "]= ")
+          lua:append("[", as_lua(k), "]= ")
         end
         if k == "source" then
-          lua:append(repr(tostring(v)))
+          lua:append(tostring(v):as_lua())
         else
-          lua:append(AST.is_syntax_tree(v) and self:compile(v, compile_actions) or repr(v))
+          lua:append(as_lua(v))
         end
       end
       lua:append("}")
@@ -849,7 +858,7 @@ do
             if #lua.bits > 0 then
               lua:append("..")
             end
-            lua:append(repr(string_buffer))
+            lua:append(string_buffer:as_lua())
             string_buffer = ""
           end
           local bit_lua = self:compile(bit, compile_actions)
@@ -875,7 +884,7 @@ do
         if #lua.bits > 0 then
           lua:append("..")
         end
-        lua:append(repr(string_buffer))
+        lua:append(string_buffer:as_lua())
       end
       if #lua.bits > 1 then
         lua:parenthesize()
diff --git a/nomsu_compiler.moon b/nomsu_compiler.moon
index 19d4049..0718bca 100644
--- a/nomsu_compiler.moon
+++ b/nomsu_compiler.moon
@@ -14,7 +14,7 @@ lpeg = require 'lpeg'
 re = require 're'
 utils = require 'utils'
 Files = require 'files'
-{:repr, :stringify, :equivalent} = utils
+{:stringify, :equivalent} = utils
 {:List, :Dict, :Text} = require 'containers'
 export colors, colored
 colors = require 'consolecolors'
@@ -104,7 +104,7 @@ with NomsuCompiler
         -- Nomsu types:
         _List:List, _Dict:Dict,
         -- Utilities and misc.
-        repr:repr, stringify:stringify, utils:utils, lpeg:lpeg, re:re, Files:Files,
+        stringify:stringify, utils:utils, lpeg:lpeg, re:re, Files:Files,
         :AST, TESTS: Dict{}, globals: Dict{}
         :LuaCode, :NomsuCode, :Source
         nomsu:NomsuCompiler
@@ -202,16 +202,16 @@ with NomsuCompiler
     add_lua_string_bits = (val_or_stmt, code)=>
         cls_str = val_or_stmt == "value" and "LuaCode.Value(" or "LuaCode("
         if code.type != "Text"
-            return LuaCode.Value(code.source, cls_str, repr(tostring(code.source)), ", ", @compile(code), ")")
+            return LuaCode.Value(code.source, cls_str, tostring(code.source)\as_lua!, ", ", @compile(code), ")")
         add_bit_lua = (lua, bit_lua)->
             bit_leading_len = #(bit_lua\match("^[^\n]*"))
             lua\append(lua\trailing_line_len! + bit_leading_len > MAX_LINE and ",\n    " or ", ")
             lua\append(bit_lua)
         operate_on_text = (text)->
-            lua = LuaCode.Value(text.source, cls_str, repr(tostring(text.source)))
+            lua = LuaCode.Value(text.source, cls_str, tostring(text.source)\as_lua!)
             for bit in *text
                 if type(bit) == "string"
-                    add_bit_lua(lua, repr(bit))
+                    add_bit_lua(lua, bit\as_lua!)
                 elseif bit.type == "Text"
                     add_bit_lua(lua, operate_on_text(bit))
                 else
@@ -270,13 +270,13 @@ with NomsuCompiler
         ["tests"]: (tree)=> LuaCode.Value(tree.source, "TESTS")
         ["test 1"]: (tree, body)=>
             test_str = table.concat [tostring(@tree_to_nomsu(line)) for line in *body], "\n"
-            LuaCode tree.source, "TESTS[#{repr(tostring(tree.source))}] = ", repr(test_str)
+            LuaCode tree.source, "TESTS[#{tostring(tree.source)\as_lua!}] = ", test_str\as_lua!
 
         ["is jit"]: (tree, code)=>
             return LuaCode.Value(tree.source, jit and "true" or "false")
 
         ["Lua version"]: (tree, code)=>
-            return LuaCode.Value(tree.source, repr(_VERSION))
+            return LuaCode.Value(tree.source, _VERSION\as_lua!)
 
         __parent: setmetatable({}, {
             __index: (key)=>
@@ -439,11 +439,11 @@ with NomsuCompiler
 
                         elseif tok.type == "Action"
                             @compile_error tok,
-                                "Can't use this as an argument to (#{stub}), since it's not an expression, it produces: #{repr arg_lua}",
+                                "Can't use this as an argument to (#{stub}), since it's not an expression, it produces: #{tostring(arg_lua)}",
                                 "Check the implementation of (#{tok.stub}) to see if it is actually meant to produce an expression."
                         else
                             @compile_error tok,
-                                "Can't use this as an argument to (#{stub}), since it's not an expression, it produces: #{repr arg_lua}"
+                                "Can't use this as an argument to (#{stub}), since it's not an expression, it produces: #{tostring(arg_lua)}"
                     insert args, arg_lua
                 lua\concat_append args, ", "
                 lua\append ")"
@@ -452,6 +452,13 @@ with NomsuCompiler
             when "EscapedNomsu"
                 lua = LuaCode.Value tree.source, tree[1].type, "{"
                 needs_comma, i = false, 1
+                as_lua = (x)->
+                    if type(x) == 'number'
+                        tostring(x)
+                    elseif AST.is_syntax_tree(x)
+                        @compile(x, compile_actions)
+                    else x\as_lua!
+
                 for k,v in pairs(AST.is_syntax_tree(tree[1], "EscapedNomsu") and tree or tree[1])
                     if needs_comma then lua\append ", "
                     else needs_comma = true
@@ -460,11 +467,11 @@ with NomsuCompiler
                     elseif type(k) == 'string' and match(k,"[_a-zA-Z][_a-zA-Z0-9]*")
                         lua\append(k, "= ")
                     else
-                        lua\append("[", (AST.is_syntax_tree(k) and @compile(k, compile_actions) or repr(k)), "]= ")
+                        lua\append("[", as_lua(k), "]= ")
                     if k == "source"
-                        lua\append repr(tostring(v))
+                        lua\append tostring(v)\as_lua!
                     else
-                        lua\append(AST.is_syntax_tree(v) and @compile(v, compile_actions) or repr(v))
+                        lua\append as_lua(v)
                 lua\append "}"
                 return lua
             
@@ -499,9 +506,9 @@ with NomsuCompiler
                     if type(bit) == "string"
                         string_buffer ..= bit
                         continue
-                    if string_buffer ~= ""
+                    if string_buffer != ""
                         if #lua.bits > 0 then lua\append ".."
-                        lua\append repr(string_buffer)
+                        lua\append string_buffer\as_lua!
                         string_buffer = ""
                     bit_lua = @compile(bit, compile_actions)
                     unless bit_lua.is_value
@@ -516,7 +523,7 @@ with NomsuCompiler
 
                 if string_buffer ~= "" or #lua.bits == 0
                     if #lua.bits > 0 then lua\append ".."
-                    lua\append repr(string_buffer)
+                    lua\append string_buffer\as_lua!
 
                 if #lua.bits > 1
                     lua\parenthesize!
diff --git a/parser.lua b/parser.lua
index 0694e3e..5eee8ca 100644
--- a/parser.lua
+++ b/parser.lua
@@ -3,8 +3,6 @@ local re = require('re')
 lpeg.setmaxstack(20000)
 local P, R, S, C, Cmt, Carg, Cc
 P, R, S, C, Cmt, Carg, Cc = lpeg.P, lpeg.R, lpeg.S, lpeg.C, lpeg.Cmt, lpeg.Carg, lpeg.Cc
-local repr
-repr = require('utils').repr
 local DEFS
 do
   local _with_0 = { }
diff --git a/parser.moon b/parser.moon
index 9a2e2ff..78e6291 100644
--- a/parser.moon
+++ b/parser.moon
@@ -3,7 +3,6 @@ lpeg = require 'lpeg'
 re = require 're'
 lpeg.setmaxstack 20000
 {:P,:R,:S,:C,:Cmt,:Carg,:Cc} = lpeg
-{:repr} = require 'utils'
 
 DEFS = with {}
     -- Newline supports either windows-style CR+LF or unix-style LF
diff --git a/string2.lua b/string2.lua
index 5995de2..2cdfefc 100644
--- a/string2.lua
+++ b/string2.lua
@@ -119,6 +119,24 @@ local string2 = {
     end
     return table.concat(lines, "\n")
   end,
+  as_lua = function(self)
+    local escaped = gsub(self, "\\", "\\\\")
+    escaped = gsub(escaped, "\n", "\\n")
+    escaped = gsub(escaped, '"', '\\"')
+    escaped = gsub(escaped, "[^ %g]", function(c)
+      return format("\\%03d", byte(c, 1))
+    end)
+    return '"' .. escaped .. '"'
+  end,
+  as_nomsu = function(self)
+    local escaped = gsub(self, "\\", "\\\\")
+    escaped = gsub(escaped, "\n", "\\n")
+    escaped = gsub(escaped, '"', '\\"')
+    escaped = gsub(escaped, "[^ %g]", function(c)
+      return format("\\%03d", byte(c, 1))
+    end)
+    return '"' .. escaped .. '"'
+  end,
   as_lua_id = function(str)
     local orig = str
     str = gsub(str, "^ *$", "%1 ")
diff --git a/string2.moon b/string2.moon
index 2259272..662cd0d 100644
--- a/string2.moon
+++ b/string2.moon
@@ -45,6 +45,20 @@ string2 = {
             lines[#lines+1] = line
         return table.concat(lines, "\n")
 
+    as_lua: =>
+        escaped = gsub(@, "\\", "\\\\")
+        escaped = gsub(escaped, "\n", "\\n")
+        escaped = gsub(escaped, '"', '\\"')
+        escaped = gsub(escaped, "[^ %g]", (c)-> format("\\%03d", byte(c, 1)))
+        return '"'..escaped..'"'
+
+    as_nomsu: =>
+        escaped = gsub(@, "\\", "\\\\")
+        escaped = gsub(escaped, "\n", "\\n")
+        escaped = gsub(escaped, '"', '\\"')
+        escaped = gsub(escaped, "[^ %g]", (c)-> format("\\%03d", byte(c, 1)))
+        return '"'..escaped..'"'
+
     -- Convert an arbitrary text into a valid Lua identifier. This function is injective,
     -- but not idempotent. In logic terms: (x != y) => (as_lua_id(x) != as_lua_id(y)),
     -- but not (as_lua_id(a) == b) => (as_lua_id(b) == b).
diff --git a/syntax_tree.lua b/syntax_tree.lua
index 72b510e..afdb631 100644
--- a/syntax_tree.lua
+++ b/syntax_tree.lua
@@ -1,5 +1,3 @@
-local repr
-repr = require('utils').repr
 local insert, remove, concat
 do
   local _obj_0 = table
@@ -15,6 +13,24 @@ AST.is_syntax_tree = function(n, t)
   end
   return type(n) == 'table' and getmetatable(n) and AST[n.type] == getmetatable(n) and (t == nil or n.type == t)
 end
+local as_lua
+as_lua = function(self)
+  if type(self) == 'number' then
+    return tostring(self)
+  end
+  do
+    local mt = getmetatable(self)
+    if mt then
+      do
+        local _as_lua = mt.as_lua
+        if _as_lua then
+          return _as_lua(self)
+        end
+      end
+    end
+  end
+  return error("Not supported: " .. tostring(self))
+end
 local types = {
   "Number",
   "Var",
@@ -42,10 +58,42 @@ for _index_0 = 1, #types do
       return getmetatable(x) == self
     end
     cls.__tostring = function(self)
-      return tostring(self.type) .. tostring(repr(self, (function() end)))
+      local bits
+      do
+        local _accum_0 = { }
+        local _len_0 = 1
+        for _index_1 = 1, #self do
+          local b = self[_index_1]
+          _accum_0[_len_0] = tostring(b)
+          _len_0 = _len_0 + 1
+        end
+        bits = _accum_0
+      end
+      for k, v in pairs(self) do
+        if not (bits[k]) then
+          table.insert(bits, "[ " .. tostring(tostring(k)) .. "]=" .. tostring(tostring(v)))
+        end
+      end
+      return tostring(self.type) .. "{" .. tostring(table.concat(bits, ", ")) .. "}"
     end
-    cls.__repr = function(self)
-      return tostring(self.type) .. tostring(repr(self, (function() end)))
+    cls.as_lua = function(self)
+      local bits
+      do
+        local _accum_0 = { }
+        local _len_0 = 1
+        for _index_1 = 1, #self do
+          local b = self[_index_1]
+          _accum_0[_len_0] = as_lua(b)
+          _len_0 = _len_0 + 1
+        end
+        bits = _accum_0
+      end
+      for k, v in pairs(self) do
+        if not (bits[k]) then
+          table.insert(bits, "[ " .. tostring(as_lua(k)) .. "]=" .. tostring(as_lua(v)))
+        end
+      end
+      return tostring(self.type) .. "{" .. tostring(table.concat(bits, ", ")) .. "}"
     end
     cls.source_code_for_tree = setmetatable({ }, {
       __index = function(self, t)
diff --git a/syntax_tree.moon b/syntax_tree.moon
index 305a1ee..d2f5d37 100644
--- a/syntax_tree.moon
+++ b/syntax_tree.moon
@@ -1,6 +1,5 @@
 -- This file contains the datastructures used to represent parsed Nomsu syntax trees,
 -- as well as the logic for converting them to Lua code.
-{:repr} = require 'utils'
 {:insert, :remove, :concat} = table
 {:Source} = require "code_obj"
 unpack or= table.unpack
@@ -9,6 +8,14 @@ AST = {}
 AST.is_syntax_tree = (n, t=nil)->
     type(n) == 'table' and getmetatable(n) and AST[n.type] == getmetatable(n) and (t == nil or n.type == t)
 
+as_lua = =>
+    if type(@) == 'number'
+        return tostring(@)
+    if mt = getmetatable(@)
+        if _as_lua = mt.as_lua
+            return _as_lua(@)
+    error("Not supported: #{@}")
+
 types = {"Number", "Var", "Block", "EscapedNomsu", "Text", "List", "Dict", "DictEntry",
     "IndexChain", "Action", "FileChunks", "Error", "Comment"}
 for name in *types
@@ -19,8 +26,18 @@ for name in *types
         .__name = name
         .type = name
         .is_instance = (x)=> getmetatable(x) == @
-        .__tostring = => "#{@type}#{repr @, (->)}"
-        .__repr = => "#{@type}#{repr @, (->)}"
+        .__tostring = =>
+            bits = [tostring(b) for b in *@]
+            for k,v in pairs(@)
+                unless bits[k]
+                    table.insert(bits, "[ #{tostring(k)}]=#{tostring(v)}")
+            return "#{@type}{#{table.concat(bits, ", ")}}"
+        .as_lua = =>
+            bits = [as_lua(b) for b in *@]
+            for k,v in pairs(@)
+                unless bits[k]
+                    table.insert(bits, "[ #{as_lua(k)}]=#{as_lua(v)}")
+            return "#{@type}{#{table.concat(bits, ", ")}}"
         .source_code_for_tree = setmetatable({}, {__index:(t)=>
             s = t.source
             Files = require 'files'