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.
Refiner	Applies to Source or Curator to refine and process generated items.

In addition, Fall provides the following functions to refine and compose individual modules:

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

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 an Action that change directory and open.

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

const action = composeActions(
  builtin.action.cd,
  builtin.action.open,
);