Move command line handling into a module

source/main.elna

@@ -3,7 +3,7 @@
   obtain one at https://mozilla.org/MPL/2.0/. *)
 program;
 
-import cstdlib, cstdio, cctype, common, Lexer;
+import cstdio, cctype, common, command_line_interface, Lexer;
 
 const
   SEEK_SET* := 0;
@@ -113,11 +113,6 @@ type
     end;
     location: Location
   end;
-  CommandLine = record
-    input: ^Char;
-    lex: Bool;
-    parse: Bool
-  end;
   Tokenizer* = record
     length: Word;
     data: ^Token
@@ -702,55 +697,6 @@ begin
   return lexer
 end;
 
-(*
-  Command line handling.
-*)
-
-proc parse_command_line*(argc: Int, argv: ^^Char) -> ^CommandLine;
-var
-  parameter: ^^Char;
-  i: Int;
-  result: ^CommandLine;
-begin
-  i := 1;
-  result := cast(malloc(#size(CommandLine)): ^CommandLine);
-  result^.lex := false;
-  result^.parse := false;
-  result^.input := nil;
-
-  while i < argc & result <> nil do
-    parameter := argv + i;
-
-    if strcmp(parameter^, "--lex\0".ptr) = 0 then
-      result^.lex := true
-    elsif strcmp(parameter^, "--parse\0".ptr) = 0 then
-      result^.parse := true
-    elsif parameter^^ <> '-' then
-      if result^.input <> nil then
-      write_s("Fatal error: Only one source file can be given.\n");
-      result := nil
-      else
-        result^.input := parameter^
-      end
-    else
-      write_s("Fatal error: Unknown command line options: ");
-
-      write_z(parameter^);
-      write_s(".\n");
-
-      result := nil
-    end;
-
-    i := i + 1
-  end;
-  if result <> nil & result^.input = nil then
-    write_s("Fatal error: no input files.\n");
-    result := nil
-  end;
-
-  return result
-end;
-
 (*
   Parser.
 *)