Help end syntax + line magic interaction

[rawlins]

The help end syntax takes higher precedence than the line magic syntax; this is intentional:

# This needs to be higher priority (lower number) than EscapedCommand so
# that inspecting magics (%foo?) works.

However, if a line magic is handling text that may end in a ? or ??, this can lead to unexpected results -- %somemagic whatever? leading to Object `whatever` not found. instead of the line magic ever being called. (In my case I can tell users to just add a space after the ?, but this isn't necessarily general.)

Proposed solution: if a line magic line ends in ?/??, only call the help transform if there is no whitespace intervening between the % and the help end marker. As far as I can see this should handle the intended case for using % and ? together as well as let line magics work right in general, but maybe I'm missing something. (If it is this simple I can submit a PR, implementing it looks straightforward.)

[gregory-shklover]

Same issue here. Question mark could be part of the text handled by a custom-defined magic. Current token transform handling manipulates line magic input. Suggested solution: add support for line magic hints to disable token manipulation completely.

[gregory-shklover]

Workaround:

from IPython.core.inputtransformer2 import HelpEnd, EscapedCommand HelpEnd.priority = EscapedCommand.priority + 1