+# (args, w) = parseArgs w
+| args.help
+ # (out, w) = stdio w
+ # out = out <<< "\nUsage: " <<< args.program <<< " [opts] [FILENAME]\n"
+ <<< "\t--help Show this help\n"
+ <<< "\t--lex Lex only, is mutually exclusive with --parse\n"
+ <<< "\t--parse Lex & Parse only\n\n"
+ <<< "\tFILENAME File to parse, when unspecified stdin is parsed\n"
+ # (_, w) = fclose out w
+ = (Left "", Left "", w)
+# (stdin, w) = stdio w
+# (contents, stdin, w) = readFileOrStdin stdin args.fp w
+| args.lex = case contents of
+ (Right cs) = (lexer cs, Left "Parsing Disabled", w)
+ (Left e) = (Left e, Left "Parsing disabled", w)
+= case contents of
+ (Left e) = (Left e, Left "", w)
+ (Right cs)
+ # lexout = lexer cs
+ # parsout = parser lexout
+ # stdin = stdin <<< (either (const "") toString parsout)
+ # (_, w) = fclose stdin w
+ = (lexout, parser lexout, w)
+
+parseArgs :: *World -> (Opts, *World)
+parseArgs w
+# ([p:args], w) = getCommandLine w
+= (pa args {program=p, lex=False, parse=False, fp=Nothing, help=False}, w)
+where
+ pa :: [String] -> (Opts -> Opts)
+ pa [] = id
+ pa ["--help":r] = \o.pa r {o & help=True}
+ pa ["--lex":r] = \o.pa r {o & lex=True, parse=False}
+ pa ["--parse":r] = \o.pa r {o & lex=False, parse=True}
+ pa [x:r] = \o.pa r {o & fp=Just x}
+
+readFileOrStdin :: *File (Maybe String) *World -> *(Either String [Char], *File, *World)
+readFileOrStdin stdin Nothing w
+# (cs, stdin) = readEntireFile stdin
+= (Right cs, stdin, w)
+readFileOrStdin stdin (Just fp) w
+# (b, fin, w) = fopen fp FReadText w
+| not b = (Left "Unable to open file", stdin, w)
+# (cs, fin) = readEntireFile fin
+# (b, w) = fclose fin w
+| not b = (Left "Unable to close file", stdin, w)
+= (Right cs, stdin, w)