search.md

Search design

Searching is referred to searching for a string inside a file or multiple files.

There are several types of standard searching algorithms:

• Exact - search string should appear exactly in the file, most simple.
• Regex - use full power of regular expressions for searching.
• PEG - more powerful than regex but could be harder to use and is generally less popular. This needs more research.

But there are more ideas:

• Exact with word boundaries - exact search but it must not be surrounded by any other characters, so content does not match contents because of the "s" at the end.
• Camel-Kebab-Pascal-Snake-case-insensitive (very-case-insensitive) - text_buffer search items will match all of text_buffer, TextBuffer, textBuffer, text-buffer.

In GUI editors the search is often coupled with "replace" functionality and looks like for a good reason. So maybe this is a good idea to do search first and then provide an option to move from here to replace these things?

• Exact - exact replacement, nothing fancy.
• Regex - provide handles for groups such as \1 or $1 for the first group.
• Exact with word boundaries - same as Exact, exact replacement.
• Very-case-insensitive - replace with the same style as the original style is.

How to do exact but case-insensitive search? Probably with regex, popular engines use (?i) prefix. This could also be same as very-case-insensitive in some cases.

Keymap configuration

We will probably settle at the following configuration:

settings:
  default_search: exact

keymap:
  normal:
    /: search_default
    <space>:
      s:
        e: search_exact
        r: search_regex
        b: search_exact_with_boundaries
        i: search_camel_kebab_pascal_snake_case_insensitive
  search:  # this mode is entered on pressing /
    default: insert_character
    ctrl-r: search_and_replace

So there's a way to choose a default search kind and use it by hitting / and if one needs another kind of search, one can access it by hitting in sequence Space-s and choose the preferred way. And while searching, one can hit Ctrl-r to enter a replace mode.

TODO: spec out replace mode.

Project-wide searching

Another case is project-wide searching. It is probably best achieved by the combination of external tools such as ripgrep + fzf so for now the decision is to be limited by these external tools. We can write one for ourselves if we really need to, I definitely see a case for project-wide search-and-replace of Camel-Kebab-Pascal-Snake-case-insensitive words.