Better signature abstractions. Retrieve signatures without Jedi when Jedi fails.

Author: jonathanslenders

ptpython/completer.py

@@ -157,6 +157,7 @@ def get_completions(
             return
 
         # Do Path completions (if there were no dictionary completions).
+        # TODO: not if we have dictionary completions...
         if complete_event.completion_requested or self._complete_path_while_typing(
             document
         ):
@@ -383,7 +384,7 @@ def get_completions(
         self, document: Document, complete_event: CompleteEvent
     ) -> Iterable[Completion]:
 
-        # First, find all for-loops, and assing the first item of the
+        # First, find all for-loops, and assign the first item of the
         # collections they're iterating to the iterator variable, so that we
         # can provide code completion on the iterators.
         temp_locals = self.get_locals().copy()
@@ -414,6 +415,17 @@ def _do_repr(self, obj: object) -> str:
         except BaseException:
             raise ReprFailedError
 
+    def eval_expression(self, document: Document, locals: Dict[str, Any]) -> object:
+        """
+        Evaluate
+        """
+        match = self.expression_pattern.search(document.text_before_cursor)
+        if match is not None:
+            object_var = match.groups()[0]
+            return self._lookup(object_var, locals)
+
+        return None
+
     def _get_expression_completions(
         self,
         document: Document,
@@ -423,17 +435,17 @@ def _get_expression_completions(
         """
         Complete the [ or . operator after an object.
         """
-        match = self.expression_pattern.search(document.text_before_cursor)
-        if match is not None:
-            object_var = match.groups()[0]
-            result = self._lookup(object_var, temp_locals)
+        result = self.eval_expression(document, temp_locals)
+
+        if result is not None:
 
             if isinstance(
                 result,
                 (list, tuple, dict, collections_abc.Mapping, collections_abc.Sequence),
             ):
                 yield Completion("[", 0)
-            elif result is not None:
+
+            else:
                 # Note: Don't call `if result` here. That can fail for types
                 #       that have custom truthness checks.
                 yield Completion(".", 0)

ptpython/layout.py

@@ -4,13 +4,13 @@
 import platform
 import sys
 from enum import Enum
+from inspect import _ParameterKind as ParameterKind
 from typing import TYPE_CHECKING, Optional
 
 from prompt_toolkit.application import get_app
 from prompt_toolkit.enums import DEFAULT_BUFFER, SEARCH_BUFFER
 from prompt_toolkit.filters import (
     Condition,
-    has_completions,
     has_focus,
     is_done,
     renderer_height_is_known,
@@ -248,30 +248,41 @@ def get_text_fragments() -> StyleAndTextTuples:
 
             append((Signature + ",operator", "("))
 
-            try:
-                enumerated_params = enumerate(sig.params)
-            except AttributeError:
-                # Workaround for #136: https://github.com/jonathanslenders/ptpython/issues/136
-                # AttributeError: 'Lambda' object has no attribute 'get_subscope_by_name'
-                return []
+            got_positional_only = False
+            got_keyword_only = False
+
+            for i, p in enumerate(sig.parameters):
+                # Detect transition between positional-only and not positional-only.
+                if p.kind == ParameterKind.POSITIONAL_ONLY:
+                    got_positional_only = True
+                if got_positional_only and p.kind != ParameterKind.POSITIONAL_ONLY:
+                    got_positional_only = False
+                    append((Signature, "/"))
+                    append((Signature + ",operator", ", "))
 
-            for i, p in enumerated_params:
-                # Workaround for #47: 'p' is None when we hit the '*' in the signature.
-                #                     and sig has no 'index' attribute.
-                # See: https://github.com/jonathanslenders/ptpython/issues/47
-                #      https://github.com/davidhalter/jedi/issues/598
-                description = p.to_string() if p else "*"
+                if not got_keyword_only and p.kind == ParameterKind.KEYWORD_ONLY:
+                    got_keyword_only = True
+                    append((Signature, "*"))
+                    append((Signature + ",operator", ", "))
+
+                description = p.name
                 sig_index = getattr(sig, "index", 0)
 
                 if i == sig_index:
                     # Note: we use `_Param.description` instead of
                     #       `_Param.name`, that way we also get the '*' before args.
-                    append((Signature + ",current-name", str(description)))
+                    append((Signature + ",current-name", description))
                 else:
                     append((Signature, str(description)))
+
+                if p.default:
+                    # NOTE: For the jedi-based completion, the default is
+                    #       currently still part of the name.
+                    append((Signature, f"={p.default}"))
+
                 append((Signature + ",operator", ", "))
 
-            if sig.params:
+            if sig.parameters:
                 # Pop last comma
                 result.pop()
 
@@ -577,7 +588,7 @@ def menu_position():
                 """
                 b = python_input.default_buffer
 
-                if b.complete_state is None and python_input.signatures:
+                if python_input.signatures:
                     row, col = python_input.signatures[0].bracket_start
                     index = b.document.translate_row_col_to_index(row - 1, col)
                     return index

ptpython/python_input.py

@@ -66,8 +66,9 @@
 from .layout import CompletionVisualisation, PtPythonLayout
 from .lexer import PtpythonLexer
 from .prompt_style import ClassicPrompt, IPythonPrompt, PromptStyle
+from .signatures import Signature, get_signatures_using_eval, get_signatures_using_jedi
 from .style import generate_style, get_all_code_styles, get_all_ui_styles
-from .utils import get_jedi_script_from_document, unindent_code
+from .utils import unindent_code
 from .validator import PythonValidator
 
 __all__ = ["PythonInput"]
@@ -260,7 +261,7 @@ def __init__(
 
         self.enable_syntax_highlighting: bool = True
         self.enable_fuzzy_completion: bool = False
-        self.enable_dictionary_completion: bool = False
+        self.enable_dictionary_completion: bool = False  # Also eval-based completion.
         self.complete_private_attributes: CompletePrivateAttributes = (
             CompletePrivateAttributes.ALWAYS
         )
@@ -330,7 +331,7 @@ def __init__(
         self.current_statement_index: int = 1
 
         # Code signatures. (This is set asynchronously after a timeout.)
-        self.signatures: List[Any] = []
+        self.signatures: List[Signature] = []
 
         # Boolean indicating whether we have a signatures thread running.
         # (Never run more than one at the same time.)
@@ -917,36 +918,16 @@ def _on_input_timeout(self, buff: Buffer, loop=None) -> None:
         loop = loop or get_event_loop()
 
         def run():
-            script = get_jedi_script_from_document(
+            # First, get signatures from Jedi. If we didn't found any and if
+            # "dictionary completion" (eval-based completion) is enabled, then
+            # get signatures using eval.
+            signatures = get_signatures_using_jedi(
                 document, self.get_locals(), self.get_globals()
             )
-
-            # Show signatures in help text.
-            if script:
-                try:
-                    signatures = script.get_signatures()
-                except ValueError:
-                    # e.g. in case of an invalid \\x escape.
-                    signatures = []
-                except Exception:
-                    # Sometimes we still get an exception (TypeError), because
-                    # of probably bugs in jedi. We can silence them.
-                    # See: https://github.com/davidhalter/jedi/issues/492
-                    signatures = []
-                else:
-                    # Try to access the params attribute just once. For Jedi
-                    # signatures containing the keyword-only argument star,
-                    # this will crash when retrieving it the first time with
-                    # AttributeError. Every following time it works.
-                    # See: https://github.com/jonathanslenders/ptpython/issues/47
-                    #      https://github.com/davidhalter/jedi/issues/598
-                    try:
-                        if signatures:
-                            signatures[0].params
-                    except AttributeError:
-                        pass
-            else:
-                signatures = []
+            if not signatures and self.enable_dictionary_completion:
+                signatures = get_signatures_using_eval(
+                    document, self.get_locals(), self.get_globals()
+                )
 
             self._get_signatures_thread_running = False
 
@@ -957,11 +938,8 @@ def run():
 
                 # Set docstring in docstring buffer.
                 if signatures:
-                    string = signatures[0].docstring()
-                    if not isinstance(string, str):
-                        string = string.decode("utf-8")
                     self.docstring_buffer.reset(
-                        document=Document(string, cursor_position=0)
+                        document=Document(signatures[0].docstring, cursor_position=0)
                     )
                 else:
                     self.docstring_buffer.reset()