(https://github.com/ruby/irb/pull/642)
* Define RelineInputMethod::HISTORY
The HistorySavingAbility module doesn't do anything if the input method
class doesn't define HISTORY.
- 3ac96be660/lib/irb/history.rb (L10)
- 3ac96be660/lib/irb/history.rb (L34)
This patch defines RelineInputMethod::HISTORY to avoid this.
* Improve history-saving's ability check
Instead of checking the existence of `input_method_class::HISTORY`, we should
make every input method class declare if it supports history saving or not.
Since the default value is `false`, it shouldn't break any custom input method
that inherits from `IRB::InputMethod`.
https://github.com/ruby/irb/commit/aec7a5b3f5
(https://github.com/ruby/irb/pull/613)
Since `IRB.conf[:SAVE_HISTORY]` is assigned with 1000 by default, history-saving
is a feature enabled by default. So it should not be treated as an extension,
which adds unnecessary complexity to the code.
Stan Lo