Add self-insert-nonempty as fast implementation of space-trimming #6713
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This should be documented in cmds/bind.rst. |
src/reader.cpp
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| arr[i] = next_event.get_char(); | ||
| } else if (evt.input_style == char_event_t::style_nonempty && accumulated_chars.empty() && | ||
| active_edit_line()->empty()) { | ||
| // Skip this ltrim character. |
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Let's see if I understand this correctly: this bit is just an optimisation?
We can skip all normal chars on an empty commandline if the binding used is self-insert-nonempty. If anything else modifies the commandline, we won't be going through this path, and then once we do go back here the commandline might not be empty anymore.
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Right, this is just an optimization, but an important one . This loop accumulates normal input, while there's input available. If we break out of the loop, we end up redrawing (and redrawing on every space would be expensive).
| @@ -111,6 +112,17 @@ class char_event_t { | |||
| /// The type of event. | |||
| char_event_type_t type; | |||
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| /// Hackish: the input style, which describes how char events (only) are applied to the command | |||
| /// line. Note this is set only after applying bindings; it is not set from readb(). | |||
| enum input_style_t : uint8_t { | |||
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I was surprised for a bit because the enum is called input_style_t but it's used elsewhere using char_event_t.
It's obvious after a second look, but maybe it's better to make it a top-level enum class like the others above, since it needs to be public anyways.
This adds a new readline command self-insert-notfirst, which is analogous to self-insert, except that it does nothing if the cursor is at the beginning. This will serve as a higher-performance implementation for stripping leading spaces on paste.
This adds basic support for self-insert-notfirst. When we see a self-insert-nonempty char event, we kick it back to the outer loop, which only inserts the character if the cursor is not at the beginning.
This changes a5a643f to use the new self-insert-notfirst binding. It also adds a test.
This teaches the reader fast-path to use self-insert-notfirst, allowing it to handle spaces. This greatly increases the performance of paste by reducing redraws. Fixes fish-shell#6603. Somewhat improves fish-shell#6704
Review feedback from #6713 (review)
Review feedback from #6713 (review)
This is the 3.1.1 set of changes to improve pasting behavior. cherry-picked from #6713
(Note if we merge this, it will be into 3.1.1 as well as master.)
This implements the idea I sketched in this comment. It adds a new readline command
self-insert-nonemptywhich inserts characters unless the command line is empty.The space-trim-on-paste binding then becomes
bind --preset -M paste " " self-insert-nonemptyand it is quite noticeably faster.For 3.1.1, I am OK merging this or reverting a5a643f. Post if you have strong feelings either way.