Starting to create a way of how context sensitive completions can be made.

This involves playing heavily with the parser pgen2. We use its stack to check for all possible tokens/keywords.

jedi/api/__init__.py

@@ -186,7 +186,7 @@ class Script(object):
             return new_defs
 
         goto_path = self._user_context.get_path_under_cursor()
-        context = self._user_context.get_context()
+        context = self._user_context.get_reverse_context()
         definitions = []
         if next(context) in ('class', 'def'):
             definitions = [self._evaluator.wrap(self._parser.user_scope())]
@@ -253,7 +253,7 @@ class Script(object):
             return definitions
 
         goto_path = self._user_context.get_path_under_cursor()
-        context = self._user_context.get_context()
+        context = self._user_context.get_reverse_context()
         user_stmt = self._parser.user_stmt()
         user_scope = self._parser.user_scope()
 

jedi/api/completion.py

@@ -1,6 +1,7 @@
 from itertools import chain
 import re
 
+from jedi.parser import token
 from jedi.parser import tree
 from jedi import debug
 from jedi import settings
@@ -70,7 +71,7 @@ class Completion:
 
         user_stmt = self._parser.user_stmt_with_whitespace()
 
-        completion_names = self.get_completions(user_stmt, completion_parts)
+        completion_names = self._get_context_completions(user_stmt, completion_parts)
 
         if not completion_parts.has_dot:
             call_signatures = self._call_signatures_method()
@@ -85,30 +86,73 @@ class Completion:
                                                   x.name.startswith('_'),
                                                   x.name.lower()))
 
-    def get_completions(self, user_stmt, completion_parts):
-        # TODO this closure is ugly. it also doesn't work with
-        # simple_complete (used for Interpreter), somehow redo.
+    def _get_context_completions(self, user_stmt, completion_parts):
+        """
+        Analyzes the context that a completion is made in and decides what to
+        return.
+
+        Could provide context for:
+        - from/import completions
+        - as nothing
+        - statements that start always on new line
+                       'import', 'class', 'def', 'try', 'except',
+                       'finally', 'while', with
+        - statements that start always on new line or after ; or after :
+                        return raise continue break del pass global nonlocal assert
+        - def/class nothing
+        - async for/def/with
+        - \n@/del/return/raise no keyword (after keyword no keyword)?
+        - after keyword
+        - continue/break/pass nothing
+        - global/nonlocal search global
+        - after operator no keyword: return
+        - yield like return + after ( and =
+        - almost always ok
+              'and', 'for', 'if', 'else', 'in', 'is', 'lambda', 'not', 'or'
+        - after operations no keyword:
+                + = * ** - etc Maybe work with the parser state?
+
+        # hard:
+        - await
+        - yield from / raise from / from import difference
+        - In args: */**: no completion
+        - In params (also lambda): no completion before =
+        """
         module = self._evaluator.wrap(self._parser.module())
         names, level, only_modules, unfinished_dotted = \
             helpers.check_error_statements(module, self._pos)
+
+        grammar = self._evaluator.grammar
+        stack = helpers.get_stack_at_position(grammar, module, self._pos)
+        allowed_keywords, allowed_tokens = \
+            helpers.get_possible_completion_types(grammar, stack)
+
+        completion_names = list(self._get_keyword_completion_names(allowed_keywords))
+        if token.NAME in allowed_tokens:
+            # Differentiate between import names and other names.
+            completion_names += self._simple_complete(completion_parts)
+
         completion_names = []
         if names is not None:
             imp_names = tuple(str(n) for n in names if n.end_pos < self._pos)
             i = imports.Importer(self._evaluator, imp_names, module, level)
             completion_names = i.completion_names(self._evaluator, only_modules)
 
+        return completion_names
+
         # TODO this paragraph is necessary, but not sure it works.
-        context = self._user_context.get_context()
-        if not next(context).startswith('.'):  # skip the path
-            if next(context) == 'from':
-                # completion is just "import" if before stands from ..
-                if unfinished_dotted:
-                    return completion_names
-                else:
-                    return [keywords.keyword(self._evaluator, 'import').name]
+        context = self._user_context.get_backwards_context_tokens()
+        x = next(context, None)
+        #print(x)
+        #if not x.string.startswith('.'):  # skip the path
+        if next(context, None).string == 'from':
+            # completion is just "import" if before stands from ..
+            if unfinished_dotted:
+                return completion_names
+            else:
+                return [keywords.keyword(self._evaluator, 'import').name]
 
         if isinstance(user_stmt, tree.Import):
-            module = self._parser.module()
             completion_names += imports.completion_names(self._evaluator,
                                                          user_stmt, self._pos)
             return completion_names
@@ -126,6 +170,10 @@ class Completion:
             completion_names += self._simple_complete(completion_parts)
         return completion_names
 
+    def _get_keyword_completion_names(self, keywords):
+        for keyword in keywords:
+            yield keywords.keyword(self._evaluator, keyword).name
+
     def _simple_complete(self, completion_parts):
         if not completion_parts.path and not completion_parts.has_dot:
             scope = self._parser.user_scope()

jedi/api/helpers.py

@@ -4,8 +4,11 @@ Helpers for the API
 import re
 from collections import namedtuple
 
+from jedi import common
 from jedi.parser import tree as pt
 from jedi.evaluate import imports
+from jedi import parser
+from jedi.parser import tokenize, token
 
 
 CompletionParts = namedtuple('CompletionParts', ['path', 'has_dot', 'name'])
@@ -46,6 +49,83 @@ def check_error_statements(module, pos):
     return None, 0, False, False
 
 
+def get_code_until(code, start_pos, end_pos):
+    lines = common.splitlines(code)
+    line_difference = end_pos[0] - start_pos[0]
+    if line_difference == 0:
+        end_line_length = end_pos[1] - start_pos[1]
+    else:
+        end_line_length = end_pos[1]
+
+    if line_difference > len(lines) or end_line_length > len(lines[-1]):
+        raise ValueError("The end_pos seems to be after the code part.")
+
+    new_lines = lines[:line_difference] + [lines[-1][:end_line_length]]
+    return '\n'.join(new_lines)
+
+
+def get_stack_at_position(grammar, module, pos):
+    """
+    Returns the possible node names (e.g. import_from, xor_test or yield_stmt).
+    """
+    for error_statement in module.error_statement_stacks:
+        if error_statement.first_pos < pos <= error_statement.next_start_pos:
+            code = error_statement.get_code()
+            code = get_code_until(code, error_statement.first_pos, pos)
+            break
+    else:
+        raise NotImplementedError
+
+    class EndMarkerReached(Exception):
+        pass
+
+    def tokenize_without_endmarker(code):
+        for token_ in tokenize.source_tokens(code):
+            if token_[0] == token.ENDMARKER:
+                raise EndMarkerReached()
+            else:
+                yield token_
+
+    p = parser.Parser(grammar, code, tokenizer=tokenize_without_endmarker(code),
+                      start_parsing=False)
+    try:
+        p.parse()
+    except EndMarkerReached:
+        return p.pgen_parser.stack
+
+
+def get_possible_completion_types(grammar, stack):
+    def add_results(label_index):
+        try:
+            grammar_labels.append(inversed_tokens[label_index])
+        except KeyError:
+            try:
+                keywords.append(inversed_keywords[label_index])
+            except KeyError:
+                t, v = grammar.labels[label_index]
+                assert t >= 256
+                # See if it's a symbol and if we're in its first set
+                inversed_keywords
+                itsdfa = grammar.dfas[t]
+                itsstates, itsfirst = itsdfa
+                for first_label_index in itsfirst.keys():
+                    add_results(first_label_index)
+
+    dfa, state, node = stack[-1]
+    states, first = dfa
+    arcs = states[state]
+
+    inversed_keywords = dict((v, k) for k, v in grammar.keywords.items())
+    inversed_tokens = dict((v, k) for k, v in grammar.tokens.items())
+
+    keywords = []
+    grammar_labels = []
+    for label_index, new_state in arcs:
+        add_results(label_index)
+
+    return keywords, grammar_labels
+
+
 def importer_from_error_statement(error_statement, pos):
     def check_dotted(children):
         for name in children[::2]:

jedi/parser/__init__.py

@@ -24,7 +24,7 @@ from jedi.parser import token
 from jedi.parser.token import (DEDENT, INDENT, ENDMARKER, NEWLINE, NUMBER,
                                STRING, OP, ERRORTOKEN)
 from jedi.parser.pgen2.pgen import generate_grammar
-from jedi.parser.pgen2.parse import PgenParser
+from jedi.parser.pgen2.parse import PgenParser, token_to_ilabel
 
 OPERATOR_KEYWORDS = 'and', 'for', 'if', 'else', 'in', 'is', 'lambda', 'not', 'or'
 # Not used yet. In the future I intend to add something like KeywordStatement
@@ -60,12 +60,20 @@ def load_grammar(version='3.4'):
 
 
 class ErrorStatement(object):
-    def __init__(self, stack, next_token, position_modifier, next_start_pos):
+    def __init__(self, stack, arcs, next_token, position_modifier, next_start_pos):
         self.stack = stack
+        self.arcs = arcs
         self._position_modifier = position_modifier
         self.next_token = next_token
         self._next_start_pos = next_start_pos
 
+    def __repr__(self):
+        return '<%s next: %s@%s>' % (
+            type(self).__name__,
+            repr(self.next_token),
+            self.next_start_pos
+        )
+
     @property
     def next_start_pos(self):
         s = self._next_start_pos
@@ -81,6 +89,16 @@ class ErrorStatement(object):
         first_type, nodes = self.stack[0]
         return first_type
 
+    def is_a_valid_token(self, type_, value):
+        ilabel = token_to_ilabel(type_, value)
+        for i, newstate in self.arcs:
+            if ilabel == i:
+                return True
+        return False
+
+    def get_code(self):
+        return ''.join(node.get_code() for _, nodes in self.stack for node in nodes)
+
 
 class ParserSyntaxError(object):
     def __init__(self, message, position):
@@ -119,8 +137,10 @@ class Parser(object):
         'lambdef_nocond': pt.Lambda,
     }
 
-    def __init__(self, grammar, source, start, tokenizer=None):
-        start_number = grammar.symbol2number[start]
+    def __init__(self, grammar, source, start_symbol='file_input',
+                 tokenizer=None, start_parsing=True):
+        # Todo Remove start_parsing (with False)
+        start_number = grammar.symbol2number[start_symbol]
 
         self._used_names = {}
         self._scope_names_stack = [{}]
@@ -131,27 +151,42 @@ class Parser(object):
         # For the fast parser.
         self.position_modifier = pt.PositionModifier()
 
-        added_newline = False
+        self._added_newline = False
         # The Python grammar needs a newline at the end of each statement.
-        if not source.endswith('\n') and start == 'file_input':
+        if not source.endswith('\n') and start_symbol == 'file_input':
             source += '\n'
-            added_newline = True
+            self._added_newline = True
 
-        p = PgenParser(grammar, self.convert_node, self.convert_leaf,
-                       self.error_recovery, start_number)
+        self.pgen_parser = PgenParser(
+            grammar, self.convert_node, self.convert_leaf,
+            self.error_recovery, start_number
+        )
+
+        self._start_symbol = start_symbol
+        self._grammar = grammar
+        self._tokenizer = tokenizer
         if tokenizer is None:
-            tokenizer = tokenize.source_tokens(source)
+            self._tokenizer = tokenize.source_tokens(source, use_exact_op_types=True)
 
-        self._parsed = p.parse(self._tokenize(tokenizer))
+        self._parsed = None
 
-        if start == 'file_input' != self._parsed.type:
+        if start_parsing:
+            self.parse()
+
+    def parse(self):
+        if self._parsed is not None:
+            return self._parsed
+
+        self._parsed = self.pgen_parser.parse(self._tokenize(self._tokenizer))
+
+        if self._start_symbol == '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:
-            self._parsed = self.convert_node(grammar,
-                                             grammar.symbol2number['file_input'],
+            self._parsed = self.convert_node(self._grammar,
+                                             self._grammar.symbol2number['file_input'],
                                              [self._parsed])
 
-        if added_newline:
+        if self._added_newline:
             self.remove_last_newline()
 
     def get_parsed_node(self):
@@ -161,8 +196,6 @@ class Parser(object):
         for typ, value, start_pos, prefix in tokenizer:
             if typ == ERRORTOKEN:
                 raise ParseError
-            elif typ == OP:
-                typ = token.opmap[value]
             yield typ, value, prefix, start_pos
 
     def error_recovery(self, grammar, stack, typ, value, start_pos, prefix,
@@ -301,7 +334,7 @@ class ParserWithRecovery(Parser):
         #if self.options["print_function"]:
         #    python_grammar = pygram.python_grammar_no_print_statement
         #else:
-        super(ParserWithRecovery, self).__init__(grammar, source, 'file_input', tokenizer)
+        super(ParserWithRecovery, self).__init__(grammar, source, tokenizer=tokenizer)
 
         self.module = self._parsed
         self.module.used_names = self._used_names
@@ -309,7 +342,7 @@ class ParserWithRecovery(Parser):
         self.module.global_names = self._global_names
         self.module.error_statement_stacks = self._error_statement_stacks
 
-    def error_recovery(self, grammar, stack, typ, value, start_pos, prefix,
+    def error_recovery(self, grammar, stack, arcs, typ, value, start_pos, prefix,
                        add_token_callback):
         """
         This parser is written in a dynamic way, meaning that this parser
@@ -345,7 +378,7 @@ class ParserWithRecovery(Parser):
             stack[index]
 
         #print('err', token.tok_name[typ], repr(value), start_pos, len(stack), index)
-        self._stack_removal(grammar, stack, index + 1, value, start_pos)
+        self._stack_removal(grammar, stack, arcs, index + 1, value, start_pos)
         if typ == INDENT:
             # For every deleted INDENT we have to delete a DEDENT as well.
             # Otherwise the parser will get into trouble and DEDENT too early.
@@ -366,7 +399,7 @@ class ParserWithRecovery(Parser):
             # doesn't stop you from defining `continue` in a module, etc.
             add_token_callback(typ, value, prefix, start_pos)
 
-    def _stack_removal(self, grammar, stack, start_index, value, start_pos):
+    def _stack_removal(self, grammar, stack, arcs, start_index, value, start_pos):
         def clear_names(children):
             for c in children:
                 try:
@@ -393,7 +426,7 @@ class ParserWithRecovery(Parser):
             if nodes and nodes[0] in ('def', 'class', 'lambda'):
                 self._scope_names_stack.pop()
         if failed_stack:
-            err = ErrorStatement(failed_stack, value, self.position_modifier, start_pos)
+            err = ErrorStatement(failed_stack, arcs, value, self.position_modifier, start_pos)
             self._error_statement_stacks.append(err)
 
         self._last_failed_start_pos = start_pos
@@ -418,8 +451,6 @@ class ParserWithRecovery(Parser):
                 self._add_syntax_error('Strange token', start_pos)
                 continue
 
-            if typ == OP:
-                typ = token.opmap[value]
             yield typ, value, prefix, start_pos
 
     def _add_syntax_error(self, message, position):

jedi/parser/fast.py

@@ -451,7 +451,7 @@ class FastTokenizer(object):
     """
     def __init__(self, source):
         self.source = source
-        self._gen = source_tokens(source)
+        self._gen = source_tokens(source, use_exact_op_types=True)
         self._closed = False
 
         # fast parser options

jedi/parser/pgen2/parse.py

@@ -34,6 +34,18 @@ class InternalParseError(Exception):
         self.start_pos = start_pos
 
 
+def token_to_ilabel(grammar, type_, value):
+    # Map from token to label
+    if type_ == tokenize.NAME:
+        # Check for reserved words (keywords)
+        try:
+            return grammar.keywords[value]
+        except KeyError:
+            pass
+
+    return grammar.tokens[type_]
+
+
 class PgenParser(object):
     """Parser engine.
 
@@ -118,15 +130,7 @@ class PgenParser(object):
 
     def addtoken(self, type_, value, prefix, start_pos):
         """Add a token; return True if this is the end of the program."""
-        # Map from token to label
-        if type_ == tokenize.NAME:
-            # Check for reserved words (keywords)
-            try:
-                ilabel = self.grammar.keywords[value]
-            except KeyError:
-                ilabel = self.grammar.tokens[type_]
-        else:
-            ilabel = self.grammar.tokens[type_]
+        ilabel = token_to_ilabel(self.grammar, type_, value)
 
         # Loop until the token is shifted; may raise exceptions
         while True:
@@ -168,7 +172,7 @@ class PgenParser(object):
                         # Done parsing, but another token is input
                         raise InternalParseError("too much input", type_, value, start_pos)
                 else:
-                    self.error_recovery(self.grammar, self.stack, type_,
+                    self.error_recovery(self.grammar, self.stack, arcs, type_,
                                         value, start_pos, prefix, self.addtoken)
                     break
 

jedi/parser/tokenize.py

@@ -14,7 +14,7 @@ from __future__ import absolute_import
 import string
 import re
 from io import StringIO
-from jedi.parser.token import (tok_name, N_TOKENS, ENDMARKER, STRING, NUMBER,
+from jedi.parser.token import (tok_name, N_TOKENS, ENDMARKER, STRING, NUMBER, opmap,
                                NAME, OP, ERRORTOKEN, NEWLINE, INDENT, DEDENT)
 from jedi._compatibility import is_py3
 
@@ -143,18 +143,19 @@ del _compile
 
 tabsize = 8
 
+# TODO add with?
 ALWAYS_BREAK_TOKENS = (';', 'import', 'class', 'def', 'try', 'except',
                        'finally', 'while', 'return')
 
 
-def source_tokens(source):
+def source_tokens(source, use_exact_op_types=False):
     """Generate tokens from a the source code (string)."""
     source = source
     readline = StringIO(source).readline
-    return generate_tokens(readline)
+    return generate_tokens(readline, use_exact_op_types)
 
 
-def generate_tokens(readline):
+def generate_tokens(readline, use_exact_op_types=False):
     """
     A heavily modified Python standard library tokenizer.
 
@@ -285,7 +286,12 @@ def generate_tokens(readline):
                     paren_level += 1
                 elif token in ')]}':
                     paren_level -= 1
-                yield OP, token, spos, prefix
+
+                if use_exact_op_types:
+                    typ = opmap[token]
+                else:
+                    typ = OP
+                yield typ, token, spos, prefix
 
     if new_line:
         end_pos = lnum + 1, 0

jedi/parser/user_context.py

@@ -1,16 +1,20 @@
 import re
 import os
 import keyword
+from collections import namedtuple
 
 from jedi import cache
 from jedi import common
 from jedi.parser import tokenize, ParserWithRecovery
 from jedi._compatibility import u
+from jedi.parser import token
 from jedi.parser.fast import FastParser
 from jedi.parser import tree
 from jedi import debug
 from jedi.common import PushBackIterator
 
+# TODO this should be part of the tokenizer not just of this user_context.
+Token = namedtuple('Token', ['type', 'string', 'start_pos', 'prefix'])
 
 REPLACE_STR = r"[bBuU]?[rR]?" + (r"(?:(')[^\n'\\]*(?:\\.[^\n'\\]*)*(?:'|$)" +
                                  '|' +
@@ -66,7 +70,7 @@ class UserContext(object):
             first_line = common.splitlines(tok_str)[0]
             column -= len(first_line)
             # Reverse the token again, so that it is in normal order again.
-            yield typ, tok_str[::-1], (self._line_temp, column), prefix[::-1]
+            yield Token(typ, tok_str[::-1], (self._line_temp, column), prefix[::-1])
 
     def _calc_path_until_cursor(self, start_pos):
         """
@@ -214,11 +218,14 @@ class UserContext(object):
                 next_is_key = True
         return None, 0, None, (0, 0)
 
-    def get_context(self, yield_positions=False):
+    def get_reverse_context(self, yield_positions=False):
+        """
+        Returns the token strings in reverse order from the start position.
+        """
         self.get_path_until_cursor()  # In case _start_cursor_pos is undefined.
         pos = self._start_cursor_pos
         while True:
-            # remove non important white space
+            # Remove non important white space.
             line = self.get_line(pos[0])
             while True:
                 if pos[1] == 0:
@@ -246,6 +253,35 @@ class UserContext(object):
                 else:
                     yield ''
 
+    def get_backwards_context_tokens(self):
+        self.get_path_until_cursor()  # In case _start_cursor_pos is undefined.
+        pos = self._start_cursor_pos
+        while True:
+            # Remove non important white space.
+            line = self.get_line(pos[0])
+            while True:
+                if pos[1] == 0:
+                    line = self.get_line(pos[0] - 1)
+                    if line and line[-1] == '\\':
+                        pos = pos[0] - 1, len(line) - 1
+                        continue
+                    else:
+                        break
+
+                if line[pos[1] - 1].isspace():
+                    pos = pos[0], pos[1] - 1
+                else:
+                    break
+
+            try:
+                token_ = next(self._get_backwards_tokenizer(pos))
+                pos = token_.start_pos
+                yield token_
+            except StopIteration:
+                # Make it clear that there's nothing coming anymore.
+                #yield Token('', token.ENDMARKER, (1, 0), '')
+                break
+
     def get_line(self, line_nr):
         if not self._line_cache:
             self._line_cache = common.splitlines(self.source)
@@ -310,7 +346,7 @@ class UserContextParser(object):
                 # process it - probably a Syntax Error (or in a comment).
                 debug.warning('No statement under the cursor.')
                 return
-            pos = next(self._user_context.get_context(yield_positions=True))
+            pos = next(self._user_context.get_reverse_context(yield_positions=True))
             user_stmt = self.module().get_statement_for_position(pos)
         return user_stmt