~ / search / caselesson 4/7

Case: ignorecase, smartcase, \c and \C

Decide whether "Note" and "note" are the same, per search or for good.

?how it works

Out of the box, Neovim matches case exactly: /note doesn't find "Note". Most people put set ignorecase smartcase in their config, and this editor behaves as if you had. With both on, an all-lowercase pattern ignores case, and a pattern with any capital letter matches case exactly. /note finds note, Note and NOTE; /Note finds only Note.

You can override that inside the pattern. \c anywhere in it means "ignore case", \C means "match case exactly". It doesn't matter where you put it, /\Cnote and /note\C are the same, so tacking it on the end of a pattern you already typed is fine.

:s has flags for the same thing: i ignores case and I matches it, whatever the options say. :%s/todo/DONE/i catches todo, Todo and TODO.

The classic surprise: with smartcase on, /Error will not find "error". Drop the capital, or add \c.

⌨keys

`\c`	pattern: ignore case for this search
`\C`	pattern: match case exactly for this search
`:set ignorecase`	ignore case in searches (:set ic, :set noic)
`:set smartcase`	match case when the pattern has a capital (:set scs)
`:s/{pat}/{new}/i`	substitute ignoring case (I: match case)

Nin neovim

Both options are off in a fresh Neovim. To get this editor's behaviour, add vim.o.ignorecase = true and vim.o.smartcase = true to your init.lua. 'smartcase' only applies to patterns you type: * and # use 'ignorecase' but ignore 'smartcase'.

3 drills

A capital makes it exact: Land on the target with one search. Lowercase versions of the word come first, so let smartcase do the work.
Force exact case with \C: The target is lowercase, but capitalised versions come first. Land on it with one search.
Neovim defaults: ignore case on demand: This drill uses Neovim's real defaults (noignorecase), so patterns match case exactly. Replace every spelling of the word with one :s command.

The drill editor loads in your browser.