Better codegen and error reporting

nomsu_decompiler.lua

@@ -11,6 +11,7 @@ do
   R, P, S = _obj_0.R, _obj_0.P, _obj_0.S
 end
 local re = require('re')
+local pretty_error = require("pretty_errors")
 local MAX_LINE = 80
 local GOLDEN_RATIO = ((math.sqrt(5) - 1) / 2)
 local utf8_char_patt = (R("\194\223") * R("\128\191") + R("\224\239") * R("\128\191") * R("\128\191") + R("\240\244") * R("\128\191") * R("\128\191") * R("\128\191"))
@@ -259,7 +260,16 @@ tree_to_inline_nomsu = function(tree)
   elseif "Comment" == _exp_0 then
     return NomsuCode:from(tree.source)
   elseif "Error" == _exp_0 then
-    return error("Can't compile errors")
+    local err_msg = pretty_error({
+      title = "Parse error",
+      error = tree.error,
+      hint = tree.hint,
+      source = tree:get_source_file(),
+      start = tree.source.start,
+      stop = tree.source.stop,
+      filename = tree.source.filename
+    })
+    return error(err_msg)
   else
     return error("Unknown type: " .. tostring(tree.type))
   end
@@ -327,13 +337,11 @@ tree_to_nomsu = function(tree)
     local indented = tree_to_nomsu(t)
     if t.type == "Action" or t.type == "MethodCall" then
       if indented:is_multiline() then
-        if not (indented:text():match("\n%S[^\n ]*$")) then
         if argnum == nil or argnum == 1 then
           return NomsuCode:from(t.source, "(\n    ", indented, "\n)")
         else
           return NomsuCode:from(t.source, "\n    ", indented)
         end
-        end
       elseif argnum and argnum > 1 then
         return NomsuCode:from(t.source, "\n    ", indented)
       else
@@ -599,6 +607,17 @@ tree_to_nomsu = function(tree)
       nomsu:add(tree.type == "List" and "[]" or "{}")
       return nomsu
     end
+    if #tree == 1 and tree[1].type == "Block" then
+      local block_lua = recurse(tree[1])
+      if block_lua:is_multiline() then
+        block_lua:add("\n")
+      end
+      if tree.type == "List" then
+        return NomsuCode:from(tree.source, "[", block_lua, "]")
+      else
+        return NomsuCode:from(tree.source, "{", block_lua, "}")
+      end
+    end
     local sep = ''
     local prev_item, needs_space = nil, { }
     for i, item in ipairs(tree) do

nomsu_decompiler.moon

@@ -2,6 +2,7 @@
 {:find, :sub, :match} = string
 {:R,:P,:S} = require 'lpeg'
 re = require 're'
+pretty_error = require("pretty_errors")
 
 MAX_LINE = 80
 GOLDEN_RATIO = ((math.sqrt(5)-1)/2)
@@ -201,7 +202,13 @@ tree_to_inline_nomsu = (tree)->
             return NomsuCode\from(tree.source)
         
         when "Error"
-            error("Can't compile errors")
+            err_msg = pretty_error{
+                title:"Parse error"
+                error:tree.error, hint:tree.hint, source:tree\get_source_file!
+                start:tree.source.start, stop:tree.source.stop, filename:tree.source.filename
+            }
+            -- Coroutine yield here?
+            error(err_msg)
         
         else
             error("Unknown type: #{tree.type}")
@@ -242,7 +249,6 @@ tree_to_nomsu = (tree)->
         indented = tree_to_nomsu(t)
         if t.type == "Action" or t.type == "MethodCall"
             if indented\is_multiline!
-                unless indented\text!\match("\n%S[^\n ]*$")
                 if argnum == nil or argnum == 1
                     return NomsuCode\from(t.source, "(\n    ", indented, "\n)")
                 else
@@ -458,6 +464,15 @@ tree_to_nomsu = (tree)->
             if #tree == 0
                 nomsu\add(tree.type == "List" and "[]" or "{}")
                 return nomsu
+
+            if #tree == 1 and tree[1].type == "Block"
+                block_lua = recurse(tree[1])
+                if block_lua\is_multiline! then block_lua\add "\n"
+                return if tree.type == "List" then
+                    NomsuCode\from(tree.source, "[", block_lua, "]")
+                else
+                    NomsuCode\from(tree.source, "{", block_lua, "}")
+
             sep = ''
             prev_item, needs_space = nil, {}
             for i, item in ipairs tree