How to implement auto closing of double quotes, parentheses, brackets with prompt_toolkit used in iPython 7.x?

Question

IPython since version 5 onward uses prompt_toolkit instead of readline, and I am trying to use its implementation of this package to enable auto closing of double quotes, parentheses and brackets. I have got as far as this code:

ip = get_ipython()
kb = ip.pt_app.key_bindings
@kb.add('"')
def _(event):
    buffer = event.current_buffer
    buffer.insert_text('"')
    buffer.insert_text('"')

This doesn't work correctly, as it merely inputs the two quotes, with the cursor positioned after them. The buffer object does not seem to have a method for moving the cursor back. There is a document object though, that the buffer contains, which has methods for inserting text before or after the cursor position. So amending the code:

ip = get_ipython()
kb = ip.pt_app.key_bindings
@kb.add('"') 
def _(event): 
    buffer = event.current_buffer 
    doc = buffer.document 
    doc.insert_before('"') 
    doc.insert_after('"')

This produces no output when '"' is pressed on the keyboard. I gather from the prompt_toolkit documentation, that the document should now be rendered to the screen, but I'm lost as to how to get this done. All help appreciated!

score 1 · Answer 1 · answered Jul 13 '19 at 06:31

I have found the solution to the immediate problem - my code was missing a parameter:

def _(event):
    buffer = event.current_buffer
    buffer.insert_text('"')
    buffer.insert_text('"', move_cursor=False)

A fuller answer regarding the rendering of the document object would still be appreciated, as that will be required for other related operations, such as deleting the matched quotes.

How to implement auto closing of double quotes, parentheses, brackets with prompt_toolkit used in iPython 7.x?

1 Answers1