Fix bug on syntax errors in the interactive loop.

';f' would first give a parse error, and then try to execute 'f'.  Now
it just gives the parse error, as expected.

bin/oil.py

@@ -95,22 +95,26 @@ def _tlog(msg):
_tlog('after imports')


def InteractiveLoop(opts, ex, c_parser, w_parser, line_reader, arena):
def InteractiveLoop(opts, ex, c_parser, arena):
  if opts.show_ast:
    ast_f = fmt.DetectConsoleOutput(sys.stdout)
  else:
    ast_f = None

  status = 0
  while True:
    # Why is this the way to handle Control-C?
    # Also, we shouldn't exit the shell!
    try:
      w = c_parser.Peek()
    except KeyboardInterrupt:
      print('Ctrl-C')
      break

    # TODO: When does this happen?
    if w is None:
      raise RuntimeError('Failed parse: %s' % c_parser.Error())

    c_id = word.CommandId(w)
    if c_id == Id.Op_Newline:
      #print('nothing to execute')
@@ -120,6 +124,7 @@ def InteractiveLoop(opts, ex, c_parser, w_parser, line_reader, arena):
      break
    else:
      node = c_parser.ParseCommandLine()
      #log('parsed node: %s', node)

      # Failed parse.
      # TODO: Need an error for an empty command, which we ignore?  GetLine
@@ -129,8 +134,9 @@ def InteractiveLoop(opts, ex, c_parser, w_parser, line_reader, arena):
        e = c_parser.Error()
        # NOTE: This is a bit verbose.
        ui.PrintErrorStack(e, arena, sys.stderr)
        w_parser.Reset()

        c_parser.Reset()
        c_parser.ResetInputObjects()
        continue

      if ast_f:
@@ -143,15 +149,10 @@ def InteractiveLoop(opts, ex, c_parser, w_parser, line_reader, arena):
      if opts.print_status:
        print('STATUS', repr(status))

    # Reset prompt to PS1.
    line_reader.Reset()

    # Reset internal newline state.
    # NOTE: It would actually be correct to reinitialize all objects (except
    # Env) on every iteration.  But we know that the w_parser is the only thing
    # that needs to be reset, for now.
    w_parser.Reset()
    # Reset internal newline state.  NOTE: It would actually be correct to
    # reinitialize all objects (except Env) on every iteration.
    c_parser.Reset()
    c_parser.ResetInputObjects()

  return status

@@ -311,7 +312,7 @@ def OshMain(argv0, argv, login_shell):
      completion.Init(pool, builtin.BUILTIN_DEF, mem, funcs, comp_lookup,
                      status_out, ev)

    return InteractiveLoop(opts, ex, c_parser, w_parser, line_reader, arena)
    return InteractiveLoop(opts, ex, c_parser, arena)
  else:
    # Parse the whole thing up front
    #print('Parsing file')

osh/cmd_parse.py

@@ -43,6 +43,10 @@ def __init__(self, w_parser, lexer, line_reader, arena):
    self.Reset()

  def Reset(self):
    """Reset our own internal state.

    Called by the interactive loop.
    """
    self.error_stack = []
    self.completion_stack = []

@@ -54,6 +58,21 @@ def Reset(self):

    self.pending_here_docs = []

  def ResetInputObjects(self):
    """Reset the internal state of our inputs.

    Called by the interactive loop.

    TODO: Should we just make new objects on every iteration?
    """
    # All the stuff we read from
    self.w_parser.Reset()
    #self.lexer.Reset()
    # TODO: This should be a method on Lexer.  But I'm not sure if we want to
    # reuse objects at all.
    self.lexer.line_lexer.Reset('', -1)
    self.line_reader.Reset()

  def Error(self):
    return self.error_stack

test/osh-usage.sh

@@ -100,6 +100,10 @@ osh-interactive() {

  # Parse failure
  echo ';' | $OSH -i

  # Bug fix: this shouldn't try execute 'echo OIL OIL'
  # The line lexer wasn't getting reset on parse failures.
  echo ';echo OIL OIL' | $OSH -i
}

help() {