Feature Request: Include parentheses when tab completing functions

[mskar]

When completing a function,

ptpython does not add parentheses after the function name.

I would like tab completion of functions to also add parentheses and put my cursor inside the parentheses:

Other examples:
Tab completion in IPython shows functions with parentheses in the completion menu:

but when I tab complete a function the parentheses are not included:

It would be better if IPython would add parentheses and put my cursor inside the parentheses:

Adding parentheses to completed functions is the default behavior in

• VSCode:
  
  
• PyCharm:
  
  
  And it can be enabled in the Python language server protocol (LSP).

I think this feature would be widely appreciated by users and should be the default behavior for tab completion of functions. Some users may prefer the current behavior, so ideally it would be controlled via a setting in ptpython/config.py.

[mskar]

I implemented this feature in my config.py:

Click here to see the code:

from jedi import Interpreter
from prompt_toolkit import filters
from prompt_toolkit.enums import DEFAULT_BUFFER
from prompt_toolkit.completion import CompleteEvent

def configure(repl):

    focused_insert = filters.has_focus(DEFAULT_BUFFER) & filters.vi_insert_mode
    focused_insert_and_completion = focused_insert & filters.has_completions

    def is_callable(text=""):
        completions = Interpreter(text, [locals()]).complete()
        match = next((i for i in completions if i.name == text), None)
        return match.type in ("class", "function") if match else None

    @repl.add_key_binding("tab", filter=focused_insert)
    @repl.add_key_binding("c-space", filter=focused_insert)
    def _(event):
        b = event.current_buffer
        if b.completer is None:
            return
        complete_event = CompleteEvent(completion_requested=True)
        completions = list(b.completer.get_completions(b.document, complete_event))
        if len(completions) == 1: # only one possible completion
            completion = completions[0]
            if completion.start_position:
                b.delete_before_cursor(-completion.start_position)
        elif not b.complete_state: # no completion menu
            b.start_completion(insert_common_part=True)
            completion = None
        elif b.complete_state.current_completion: # completion menu and selection
            completion = b.complete_state.current_completion
        else: # completion menu, but no selection
            b.complete_next()
            completion = b.complete_state.current_completion
        if completion:
            b.apply_completion(completion)
            if is_callable(completion.text):
                b.insert_text("()")
                b.cursor_left()

    @repl.add_key_binding("enter", filter=focused_insert_and_completion)
    def _(event):
        b = event.current_buffer
        if b.completer is None:
            return
        if b.complete_state.current_completion: # completion menu and selection
            completion = b.complete_state.current_completion
        else: # completion menu, but no selection
            b.complete_next()
            completion = b.complete_state.current_completion
        if completion:
            b.apply_completion(completion)
            if is_callable(completion.text):
                b.insert_text("()")
                b.cursor_left()

Note: This also completely changes how completion works:
Tab:

• does not cycle thru completion options and instead
• accepts completion if there is only one completion option
• starts completion if there are multiple options and the completion menu is not showing
• accepts the selected completion option if an option is selected
• accepts the first completion option if the completion menu is showing and no option is selected

Enter:

• accepts the selected completion option if an option is selected
• accepts the first completion option if the completion menu is showing and no option is selected

I decided the best solution in the end will be to use jedi to find the type from the string returned by the completer. I think it would be great if the ptython completer could provide the type. Could something like this be built into the completer?

[mskar]

I submitted a pull request that implements the changes described above: #390.