Updates to error handling in the command line parsing and usage

printing.

nomsu.lua

@@ -1,7 +1,7 @@
 NOMSU_VERSION = {
   7,
   0,
-  0
+  1
 }
 local clibtype = package.cpath:match("?%.(so)") or package.cpath:match("?%.(dll)")
 if NOMSU_PREFIX then
@@ -29,9 +29,9 @@ end
 NOMSU_VERSION = List(NOMSU_VERSION)
 local Text = require('text')
 require('builtin_metatables')
-local usage = [=[Nomsu Compiler
+local EXIT_FAILURE = 1
-
+local EXIT_SUCCESS = 0
-Usage: (nomsu | lua nomsu.lua | moon nomsu.moon) [-V version] [--help | -h] [--version] [-O optimization level] [-v] [-c] [-s] [-d debugger] [--no-core] [(file | -t tool | -e "nomsu code..." | files... -- ) [nomsu args...]]
+local usage = [=[Nomsu Usage: nomsu [-V version] [--help | -h] [--version] [-O optimization level] [-v] [-c] [-s] [-d debugger] [--no-core] [(file | -t tool | -e "nomsu code..." | files... -- ) [nomsu args...]]
 
 OPTIONS
     -t <tool> Run a tool.
@@ -101,13 +101,19 @@ local parser = re.compile([[    args <- {| (flag %sep)*
 })
 local arg_string = table.concat(arg, sep) .. sep
 local args, err = parser:match(arg_string)
-if not args or err or args.help then
+if not args or err then
   if err then
     print("Didn't understand: " .. tostring(err))
   end
   print(usage)
   os.exit(EXIT_FAILURE)
 end
+if args.help then
+  print("Nomsu - A dynamically typed programming language with natural syntax and strong metaprogramming abilities.")
+  print("https://nomsu.org\n")
+  print(usage)
+  os.exit(EXIT_SUCCESS)
+end
 if args.version then
   print(NOMSU_VERSION:joined_with("."))
   os.exit(EXIT_SUCCESS)
@@ -165,7 +171,7 @@ run = function()
     nomsu_environment:export("core")
   end
   local input_files = { }
-  if args.files then
+  if args.files and #args.files > 0 then
     local _list_1 = args.files
     for _index_0 = 1, #_list_1 do
       local f = _list_1[_index_0]
@@ -258,6 +264,15 @@ run = function()
       end
     else
       local f = Files.read(filename)
+      if not f then
+        if filename:match("^-") then
+          print("Not a valid flag: " .. filename .. "\n")
+          print(usage)
+        else
+          print("File not found: " .. filename)
+        end
+        os.exit(EXIT_FAILURE)
+      end
       if filename:match("%.lua$") then
         f = LuaCode:from(Source(filename, 1, #f), f)
       end

nomsu.moon

@@ -1,7 +1,7 @@
 #!/usr/bin/env moon
 -- This file contains the command-line Nomsu runner.
 export NOMSU_VERSION
-NOMSU_VERSION = {7, 0, 0}
+NOMSU_VERSION = {7, 0, 1}
 
 clibtype = package.cpath\match("?%.(so)") or package.cpath\match("?%.(dll)")
 
@@ -26,11 +26,11 @@ if clibtype == "dll"
 NOMSU_VERSION = List(NOMSU_VERSION)
 Text = require 'text'
 require 'builtin_metatables'
+EXIT_FAILURE = 1
+EXIT_SUCCESS = 0
 
 usage = [=[
-Nomsu Compiler
+Nomsu Usage: nomsu [-V version] [--help | -h] [--version] [-O optimization level] [-v] [-c] [-s] [-d debugger] [--no-core] [(file | -t tool | -e "nomsu code..." | files... -- ) [nomsu args...]]
-
-Usage: (nomsu | lua nomsu.lua | moon nomsu.moon) [-V version] [--help | -h] [--version] [-O optimization level] [-v] [-c] [-s] [-d debugger] [--no-core] [(file | -t tool | -e "nomsu code..." | files... -- ) [nomsu args...]]
 
 OPTIONS
     -t <tool> Run a tool.
@@ -96,11 +96,16 @@ parser = re.compile([[
 })
 arg_string = table.concat(arg, sep)..sep
 args, err = parser\match(arg_string)
-if not args or err or args.help
+if not args or err
     if err
         print("Didn't understand: #{err}")
     print usage
     os.exit(EXIT_FAILURE)
+if args.help
+    print "Nomsu - A dynamically typed programming language with natural syntax and strong metaprogramming abilities."
+    print "https://nomsu.org\n"
+    print usage
+    os.exit(EXIT_SUCCESS)
 if args.version
     print(NOMSU_VERSION\joined_with("."))
     os.exit(EXIT_SUCCESS)
@@ -139,7 +144,7 @@ run = ->
         nomsu_environment\export("core")
 
     input_files = {}
-    if args.files
+    if args.files and #args.files > 0
         for f in *args.files
             if nomsu_name = f\match("^nomsu://(.*)%.nom")
                 path, err = package.searchpath(nomsu_name, package.nomsupath, "/")
@@ -204,6 +209,13 @@ run = ->
         else
             -- Just run the file
             f = Files.read(filename)
+            if not f
+                if filename\match "^-"
+                    print "Not a valid flag: "..filename.."\n"
+                    print usage
+                else
+                    print "File not found: "..filename
+                os.exit EXIT_FAILURE
             if filename\match("%.lua$")
                 f = LuaCode\from(Source(filename, 1, #f), f)
             env = nomsu_environment.new_environment!