(or emacs irrelevant)

Swiper-isearch - a more isearch-like swiper

07 Apr 2019

Intro

Since its introduction in 2015, swiper, while nice most of the time, had two problems:

  1. Slow startup for large buffers.
  2. Candidates were lines, so if you had two or more matches on the same line, the first one was selected.

Over time, workarounds were added to address these problems.

Problem 1: slow startup

Almost right away, calling font-lock-ensure was limited to only small enough buffers.

In 2016, counsel-grep-or-swiper was introduced. It uses an external process (grep) to search through large files.

In 2017, I found ripgrep, which does a better job than grep for searching one file:

(setq counsel-grep-base-command
      "rg -i -M 120 --no-heading --line-number --color never %s %s")

The advantage here is that the search can be performed on very large files. The trade-off is that we have to type in at least 3 characters before we send it to the external process. Otherwise, when the process returns a lot of results, Emacs will lag while receiving all that output.

Problem 2: candidates are lines

In 2015, swiper-avy was added, which could also be used as a workaround for many candidates on a single line. Press C-' to visually select any candidate on screen using avy.

Enter swiper-isearch

Finally, less than a week ago, I wrote swiper-isearch to fix #1931.

Differences from the previous commands:

  • Every candidate is a point position and not a line. The UX of going from one candidate to the next is finally isearch-like, I enjoy it a lot.

  • Unlike swiper, no line numbers are added to the candidates. This allows it to be as fast as anzu.

  • Unlike counsel-grep, no external process is used. So you get feedback even after inputting a single char.

I like it a lot so far, enough to make it my default search:

(global-set-key (kbd "C-s") 'swiper-isearch)

Outro

Try out swiper-isearch, see if it can replace swiper for you; counsel-grep-or-swiper still has its place, I think. Happy hacking!

PS. Thanks to everyone who supports me on Liberapay and Patreon!

PPS. Thanks to everyone who contributes issues and patches!