Rework how arguments are parsed, hopefully fixing issue bpython#101.

marienz · marienz · commit a81339bee74d · 2010-02-10T10:50:42.000+01:00
Instead of detecting invalid arguments up front for falling back to
python we now let optparse parse and catch an exception if it fails.

Instead of splitting the list into "our" arguments and the ones for
the script we run we use the optparse allow_interspersed_args option.
diff --git a/bpython/args.py b/bpython/args.py
@@ -12,6 +12,16 @@
 from bpython import __version__
 from bpython.config import loadini, Struct, migrate_rc
 
+
+class OptionParserFailed(ValueError):
+    """Raised by the RaisingOptionParser for a bogus commandline."""
+
+
+class RaisingOptionParser(OptionParser):
+    def error(self, msg):
+        raise OptionParserFailed()
+
+
 def parse(args, extras=None):
     """Receive an argument list - if None, use sys.argv - parse all args and
     take appropriate action. Also receive optional extra options: this should
@@ -39,10 +49,16 @@ def parse(args, extras=None):
     if args is None:
         args = sys.argv[1:]
 
-    parser = OptionParser(usage='Usage: %prog [options] [file [args]]\n'
-                                'NOTE: If bpython sees an argument it does '
-                                 'not know, execution falls back to the '
-                                 'regular Python interpreter.')
+    parser = RaisingOptionParser(
+        usage='Usage: %prog [options] [file [args]]\n'
+        'NOTE: If bpython sees an argument it does '
+        'not know, execution falls back to the '
+        'regular Python interpreter.')
+    # This is not sufficient if bpython gains its own -m support
+    # (instead of falling back to Python itself for that).
+    # That's probably fixable though, for example by having that
+    # option swallow all remaining arguments in a callback.
+    parser.disable_interspersed_args()
     parser.add_option('--config', '-c', default='~/.bpython/config',
                       help='use CONFIG instead of default config file')
     parser.add_option('--interactive', '-i', action='store_true',
@@ -59,17 +75,11 @@ def parse(args, extras=None):
             extras_group.add_option(option)
         parser.add_option_group(extras_group)
 
-    all_args = set(parser._short_opt.keys() + parser._long_opt.keys())
-    if args and not all_args.intersection(arg.split('=')[0] for arg in args):
+    try:
+        options, args = parser.parse_args(args)
+    except OptionParserFailed:
         # Just let Python handle this
         os.execv(sys.executable, [sys.executable] + args)
-    else:
-        # Split args in bpython args and args for the executed file
-        real_args = list(takewhile(lambda arg: arg.split('=')[0] in all_args,
-                                   args))
-        exec_args = args[len(real_args):]
-
-    options, args = parser.parse_args(real_args)
 
     if options.version:
         print 'bpython version', __version__,
@@ -91,7 +101,7 @@ def parse(args, extras=None):
 
     loadini(config, options.config)
 
-    return config, options, exec_args
+    return config, options, args
 
 def exec_code(interpreter, args):
     """
