The parser without error recovery raises an error now if he's not able to parse something.

jedi/api/__init__.py

@@ -13,7 +13,7 @@ import sys
 from itertools import chain
 
 from jedi._compatibility import unicode, builtins
-from jedi.parser import Parser, load_grammar
+from jedi.parser import Parser, load_grammar, ParseError
 from jedi.parser.tokenize import source_tokens
 from jedi.parser import tree
 from jedi.parser.user_context import UserContext, UserContextParser
@@ -322,8 +322,9 @@ class Script(object):
 
     @memoize_default()
     def _get_under_cursor_stmt(self, cursor_txt, start_pos=None):
+        try:
             stmt = Parser(self._grammar, cursor_txt, 'eval_input').get_parsed_node()
-        if stmt is None:
+        except ParseError:
             return None
 
         user_stmt = self._parser.user_stmt()

jedi/evaluate/pep0484.py

@@ -20,7 +20,7 @@ x support for type hint comments `# type: (int, str) -> int`. See comment from
 
 from itertools import chain
 
-from jedi.parser import Parser, load_grammar
+from jedi.parser import Parser, load_grammar, ParseError
 from jedi.evaluate.cache import memoize_default
 from jedi.evaluate.compiled import CompiledObject
 from jedi import debug
@@ -32,9 +32,10 @@ def _evaluate_for_annotation(evaluator, annotation):
         for definition in evaluator.eval_element(annotation):
             if (isinstance(definition, CompiledObject) and
                     isinstance(definition.obj, str)):
+                try:
                     p = Parser(load_grammar(), definition.obj, start='eval_input')
                     element = p.get_parsed_node()
-                if element is None:
+                except ParseError:
                     debug.warning('Annotation not parsed: %s' % definition.obj)
                 else:
                     module = annotation.get_parent_until()

jedi/parser/__init__.py

@@ -35,6 +35,12 @@ STATEMENT_KEYWORDS = 'assert', 'del', 'global', 'nonlocal', 'raise', \
 _loaded_grammars = {}
 
 
+class ParseError(Exception):
+    """
+    Signals you that the code you fed the Parser was not correct Python code.
+    """
+
+
 def load_grammar(file='grammar3.4'):
     # For now we only support two different Python syntax versions: The latest
     # Python 3 and Python 2. This may change.
@@ -111,9 +117,6 @@ class Parser(object):
         'lambdef_nocond': pt.Lambda,
     }
 
-    class ParserError(Exception):
-        pass
-
     def __init__(self, grammar, source, start, tokenizer=None):
         start_number = grammar.symbol2number[start]
 
@@ -136,11 +139,9 @@ class Parser(object):
                        self.error_recovery, start_number)
         if tokenizer is None:
             tokenizer = tokenize.source_tokens(source)
-        try:
+
         self._parsed = p.parse(self._tokenize(tokenizer))
-        except Parser.ParserError:
-            self._parsed = None
-        else:
+
         if start == 'file_input' != self._parsed.type:
             # If there's only one statement, we get back a non-module. That's
             # not what we want, we want a module, so we add it here:
@@ -157,13 +158,13 @@ class Parser(object):
     def _tokenize(self, tokenizer):
         for typ, value, start_pos, prefix in tokenizer:
             if typ == ERRORTOKEN:
-                raise Parser.ParserError
+                raise ParseError
             elif typ == OP:
                 typ = token.opmap[value]
             yield typ, value, prefix, start_pos
 
     def error_recovery(self, *args, **kwargs):
-        raise Parser.ParserError
+        raise ParseError
 
     def convert_node(self, grammar, type, children):
         """

jedi/parser/pgen2/parse.py

@@ -18,8 +18,12 @@ how this parsing engine works.
 from jedi.parser import tokenize
 
 
-class ParseError(Exception):
-    """Exception to signal the parser is stuck."""
+class InternalParseError(Exception):
+    """
+    Exception to signal the parser is stuck and error recovery didn't help.
+    Basically this shouldn't happen. It's a sign that something is really
+    wrong.
+    """
 
     def __init__(self, msg, type, value, start_pos):
         Exception.__init__(self, "%s: type=%r, value=%r, start_pos=%r" %
@@ -38,7 +42,7 @@ class PgenParser(object):
     p = Parser(grammar, [converter])  # create instance
     p.setup([start])                  # prepare for parsing
     <for each input token>:
-        if p.addtoken(...):           # parse a token; may raise ParseError
+        if p.addtoken(...):           # parse a token
             break
     root = p.rootnode                 # root of abstract syntax tree
 
@@ -53,10 +57,10 @@ class PgenParser(object):
 
     Parsing is complete when addtoken() returns True; the root of the
     abstract syntax tree can then be retrieved from the rootnode
-    instance variable.  When a syntax error occurs, addtoken() raises
-    the ParseError exception.  There is no error recovery; the parser
-    cannot be used after a syntax error was reported (but it can be
-    reinitialized by calling setup()).
+    instance variable.  When a syntax error occurs, error_recovery()
+    is called. There is no error recovery; the parser cannot be used
+    after a syntax error was reported (but it can be reinitialized by
+    calling setup()).
 
     """
 
@@ -109,7 +113,7 @@ class PgenParser(object):
                                 start_pos, prefix, self.addtoken)
             # Add the ENDMARKER again.
             if not self.addtoken(type, value, prefix, start_pos):
-                raise ParseError("incomplete input", type, value, start_pos)
+                raise InternalParseError("incomplete input", type, value, start_pos)
         return self.rootnode
 
     def addtoken(self, type, value, prefix, start_pos):
@@ -162,7 +166,7 @@ class PgenParser(object):
                     self.pop()
                     if not self.stack:
                         # Done parsing, but another token is input
-                        raise ParseError("too much input", type, value, start_pos)
+                        raise InternalParseError("too much input", type, value, start_pos)
                 else:
                     self.error_recovery(self.grammar, self.stack, type,
                                         value, start_pos, prefix, self.addtoken)