Architecture

Fall decomposes the functionality of a Fuzzy Finder into the following modules:

Name	Description
Coordinator	A module that determines the style and layout of the picker.
Theme	A theme structure used to define the style of the picker.
Source	Retrieves data from arbitrary sources and generates an AsyncIterableIterator of items.
Matcher	Filters the AsyncIterableIterator received from the Source based on user input.
Curator	Combines Source and Matcher, performing data retrieval and filtering based on user input.
Sorter	Sorts items received from the Matcher or Curator.
Renderer	Processes sorted items from the Sorter for user display.
Previewer	Generates content for previewing the currently selected item.
Action	Executes actions on the selected target item.

In addition, Fall provides the following features to refine and combine individual modules:

Name	Description
Source refiner (refineSource)	Applies to Source to refine and process generated items.
Curator refiner (refineCurator)	Applies to Curator to refine and process generated items.
Source composer (composeSources)	Combines multiple Sources to create a new Source that sequentially retrieves items from all Sources.
Matcher composer (composeMatchers)	Combines multiple Matchers to create a new Matcher that filters items through all Matchers.
Curator composer (composeCurators)	Combines multiple Curators to create a new Curator that retrieves items through all Curators.
Sorter composer (composeSorters)	Combines multiple Sorters to create a new Sorter that sorts items through all Sorters.
Renderer composer (composeRenderers)	Combines multiple Renderers to create a new Renderer that processes items through all Renderers.
Previewer composer (composePreviewers)	Combines multiple Previewers to create a new Previewer that generates content from any of the Previewers.

By combining these modules, Fall enables flexible functionality.

For example, the following code demonstrates how to create a Source that retrieves files recorded in Vim’s oldfiles that exist in the current directory:

import { refineSource } from "jsr:@vim-fall/std"
import * as builtin from "jsr:@vim-fall/std/builtin"

const source = refineSource(
  builtin.source.oldfiles,
  builtin.refiner.exists,
  builtin.refiner.cwd,
);

Similarly, the following example shows how to create a Renderer that displays NerdFont icons and relative paths:

import { composeRenderer } from "jsr:@vim-fall/std"
import * as builtin from "jsr:@vim-fall/std/builtin"

const renderer = composeRenderer(
  builtin.renderer.nerdfont,
  builtin.renderer.relativePath,
);