diff --git a/lib/metaprogramming.nom b/lib/metaprogramming.nom
index 65a625d..ac45574 100644
--- a/lib/metaprogramming.nom
+++ b/lib/metaprogramming.nom
@@ -9,8 +9,8 @@ lua> ".."
     |    local body = nomsu:typecheck(vars, "body", "Thunk");
     |    return ([[
     |nomsu:def(%s, %s, %s)
-    |]]):format(nomsu:repr(signature), nomsu:tree_to_lua(body), nomsu:repr(body.src)), nil;
-    |end), "<source can be found in lib/metaprogramming.nom>");
+    |]]):format(nomsu:repr(signature), nomsu:tree_to_lua(body), nomsu:repr(("rule %s\\n..=%s"):format(vars.signature.src, vars.body.src))), nil;
+    |end));
 
 # Rule to make nomsu macros:
 rule [escaped parse %shorthand as %longhand] =:
@@ -33,7 +33,7 @@ rule [escaped parse %shorthand as %longhand] =:
         |   end
         |   return nil, table.concat(lua_bits, "\\n");
         |end
-        |nomsu:defmacro(aliases, parsing_as, template.src);
+        |nomsu:defmacro(aliases, parsing_as, ("parse %s\\n..as %s"):format(vars.shorthand.src, vars.longhand.src));
 escaped parse \[parse %shorthand as %longhand] as \: escaped parse \%shorthand as \%longhand
 
 # Rule to make lua macros:
@@ -42,14 +42,14 @@ rule [escaped compile %macro_def to %body] =:
         |local aliases = nomsu:get_stubs(nomsu:typecheck(vars, "macro_def", "List").value);
         |local body = nomsu:typecheck(vars, "body", "Thunk");
         |local thunk = nomsu:tree_to_value(body);
-        |nomsu:defmacro(aliases, thunk, body.src);
+        |nomsu:defmacro(aliases, thunk, ("compile %s\\n..to %s"):format(vars.macro_def.src, body.src));
 rule [escaped compile %macro_def to code %body] =:
     lua> ".."
         |local aliases = nomsu:get_stubs(nomsu:typecheck(vars, "macro_def", "List").value);
         |local body = nomsu:typecheck(vars, "body", "Thunk");
         |local thunk = nomsu:tree_to_value(body);
         |local thunk_wrapper = function(nomsu, vars) return nil, thunk(nomsu, vars); end
-        |nomsu:defmacro(aliases, thunk_wrapper, body.src);
+        |nomsu:defmacro(aliases, thunk_wrapper, ("compile %s\\n..to code %s"):format(vars.macro_def.src, body.src));
 parse [compile %macro_def to %body] as: escaped compile \%macro_def to \%body
 parse [compile %macro_def to code %body] as: escaped compile \%macro_def to code \%body
 
diff --git a/nomsu.lua b/nomsu.lua
index b00560c..055c8a2 100644
--- a/nomsu.lua
+++ b/nomsu.lua
@@ -242,6 +242,7 @@ do
       assert(type(thunk) == 'function', "Bad thunk: " .. tostring(repr(thunk)))
       local canonical_args = nil
       local aliases = { }
+      self.def_number = self.def_number + 1
       for _index_0 = 1, #signature do
         local _des_0 = signature[_index_0]
         local stub, arg_names
@@ -269,13 +270,33 @@ do
           arg_names = arg_names,
           src = src,
           is_macro = is_macro,
-          aliases = aliases
+          aliases = aliases,
+          def_number = self.def_number
         }
       end
     end,
     defmacro = function(self, signature, thunk, src)
       return self:def(signature, thunk, src, true)
     end,
+    serialize_defs = function(self, after)
+      if after == nil then
+        after = 0
+      end
+      defs = { }
+      for _, def in pairs(self.defs) do
+        defs[def.def_number] = def.src or ""
+      end
+      local keys = utils.keys(defs)
+      table.sort(keys)
+      local buff = { }
+      for _index_0 = 1, #keys do
+        local i = keys[_index_0]
+        if i > after and #defs[i] > 0 then
+          insert(buff, defs[i])
+        end
+      end
+      return concat(buff, "\n")
+    end,
     call = function(self, stub, line_no, ...)
       local def = self.defs[stub]
       if def and def.is_macro and self.callstack[#self.callstack] ~= "#macro" then
@@ -1063,6 +1084,7 @@ end)]]):format(concat(lua_bits, "\n"))
       self.defs = setmetatable({ }, {
         __index = parent and parent.defs
       })
+      self.def_number = 0
       self.callstack = { }
       self.debug = false
       self.utils = utils
diff --git a/nomsu.moon b/nomsu.moon
index 0c45258..90b017c 100755
--- a/nomsu.moon
+++ b/nomsu.moon
@@ -194,6 +194,7 @@ class NomsuCompiler
         @write = (...)=> io.write(...)
         @write_err = (...)=> io.stderr\write(...)
         @defs = setmetatable({}, {__index:parent and parent.defs})
+        @def_number = 0
         @callstack = {}
         @debug = false
         @utils = utils
@@ -219,6 +220,7 @@ class NomsuCompiler
         assert type(thunk) == 'function', "Bad thunk: #{repr thunk}"
         canonical_args = nil
         aliases = {}
+        @def_number += 1
         for {stub, arg_names} in *signature
             assert stub, "NO STUB FOUND: #{repr signature}"
             if @debug then @writeln "#{colored.bright "DEFINING RULE:"} #{colored.underscore colored.magenta repr(stub)} #{colored.bright "WITH ARGS"} #{colored.dim repr(arg_names)}"
@@ -228,10 +230,22 @@ class NomsuCompiler
                 assert utils.equivalent(utils.set(arg_names), canonical_args), "Mismatched args"
             else canonical_args = utils.set(arg_names)
             insert aliases, stub
-            @defs[stub] = {:thunk, :stub, :arg_names, :src, :is_macro, :aliases}
+            @defs[stub] = {:thunk, :stub, :arg_names, :src, :is_macro, :aliases, def_number:@def_number}
 
     defmacro: (signature, thunk, src)=>
         @def(signature, thunk, src, true)
+    
+    serialize_defs: (after=0)=>
+        defs = {}
+        for _, def in pairs(@defs)
+            defs[def.def_number] = def.src or ""
+        keys = utils.keys(defs)
+        table.sort(keys)
+        buff = {}
+        for i in *keys
+            if i > after and #defs[i] > 0
+                insert buff, defs[i]
+        return concat buff, "\n"
 
     call: (stub,line_no,...)=>
         def = @defs[stub]