From cdd413a2a82bc01adc0cd75f8ff4ca47bab701df Mon Sep 17 00:00:00 2001
From: leaf corcoran <leafot@gmail.com>
Date: Tue, 19 Mar 2013 09:22:27 -0700
Subject: [PATCH] load* functions return nil and error instead of throwing
 error fixes #87

---
 moonscript/init.lua  | 18 ++++++++----------
 moonscript/init.moon | 16 ++++++++--------
 2 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/moonscript/init.lua b/moonscript/init.lua
index 7612c56..2488d6d 100644
--- a/moonscript/init.lua
+++ b/moonscript/init.lua
@@ -29,15 +29,15 @@ to_lua = function(text, options)
   end
   if "string" ~= type(text) then
     local t = type(text)
-    error("expecting string (got " .. t .. ")", 2)
+    return nil, "expecting string (got " .. t .. ")", 2
   end
   local tree, err = parse.string(text)
   if not tree then
-    error(err, 2)
+    return nil, err
   end
   local code, ltable, pos = compile.tree(tree, options)
   if not code then
-    error(compile.format_error(ltable, pos, text), 2)
+    return nil, compile.format_error(ltable, pos, text), 2
   end
   return code, ltable
 end
@@ -73,14 +73,12 @@ end
 loadstring = function(...)
   local options, str, chunk_name, mode, env = get_options(...)
   chunk_name = chunk_name or "=(moonscript.loadstring)"
-  local passed, code, ltable = pcall(function()
-    return to_lua(str, options)
-  end)
-  if not passed then
-    error(chunk_name .. ": " .. code, 2)
+  local code, ltable_or_err = to_lua(str, options)
+  if not (code) then
+    return nil, ltable_or_err
   end
   if chunk_name then
-    line_tables[chunk_name] = ltable
+    line_tables[chunk_name] = ltable_or_err
   end
   return (lua.loadstring or lua.load)(code, chunk_name, unpack({
     mode,
@@ -89,7 +87,7 @@ loadstring = function(...)
 end
 loadfile = function(fname, ...)
   local file, err = io.open(fname)
-  if not file then
+  if not (file) then
     return nil, err
   end
   local text = assert(file:read("*a"))
diff --git a/moonscript/init.moon b/moonscript/init.moon
index aa7d2ed..2c9fe41 100644
--- a/moonscript/init.moon
+++ b/moonscript/init.moon
@@ -23,15 +23,15 @@ create_moonpath = (package_path) ->
 to_lua = (text, options={}) ->
   if "string" != type text
     t = type text
-    error "expecting string (got ".. t ..")", 2
+    return nil, "expecting string (got ".. t ..")", 2
 
   tree, err = parse.string text
   if not tree
-    error err, 2
+    return nil, err
 
   code, ltable, pos = compile.tree tree, options
   if not code
-    error compile.format_error(ltable, pos, text), 2
+    return nil, compile.format_error(ltable, pos, text), 2
 
   code, ltable
 
@@ -63,17 +63,17 @@ loadstring = (...) ->
   options, str, chunk_name, mode, env = get_options ...
   chunk_name or= "=(moonscript.loadstring)"
 
-  passed, code, ltable = pcall -> to_lua str, options
-  if not passed
-    error chunk_name .. ": " .. code, 2
+  code, ltable_or_err = to_lua str, options
+  unless code
+    return nil, ltable_or_err
 
-  line_tables[chunk_name] = ltable if chunk_name
+  line_tables[chunk_name] = ltable_or_err if chunk_name
   -- the unpack prevents us from passing nil
   (lua.loadstring or lua.load) code, chunk_name, unpack { mode, env }
 
 loadfile = (fname, ...) ->
   file, err = io.open fname
-  return nil, err if not file
+  return nil, err unless file
   text = assert file\read "*a"
   file\close!
   loadstring text, fname, ...