Prompter

This library is heavily inspired by Emacs’ minibuffer and Helm. It only deals with the backend side of things, it does not handle any display.

Class overview

The key objects are prompters, sources and suggestions.

A prompt is an interface for user interactions that holds one or more sources, and each of those are populated by suggestions.

Other central concepts include:

• prompt

  current-suggestion

  A single suggestion, if any.

• source

  marks

  A list of suggestions, when enable-marks-p is non-nil.

  actions

  A list of functions that run on suggestions.

  actions-on-return

  Meant to be called over marks (or current-suggestion, when enable-marks-p is nil) when successfully returning prompt. By default, it’s the identity function.

  actions-on-marks

  On marks change (event-driven).

  actions-on-current-suggestion

  On current-suggestion change (event-driven).

Example: Find below a graphical visualization of a single prompt with sources 1 and 2, and suggestions A, B, C and D. Marks is the list composed by Suggestions A and C. The current-suggestion is Suggestion B.

Remarks:

When prompt has multiple sources, while current-suggestion is always defined for prompt, it is empty for all but one of its sources.

Marks is a concept related to source not prompt, unlike that of current-suggestion. Thus, from the point of view of a prompt’s object, the marks are the union of the marks of each of the prompt’s =source=s.

Features

Non-exhaustive list of features:

• Asynchronous suggestion computation.
• Multiple sources.
• Multiple return actions.
• Customizable matching and sorting.
• Multiple attributes per suggestion.
• Customizable initialization and cleanup functions.
• Notifications sent when suggestion list is updated.
• Per-source history.
• Resumable prompters.
• Marks actions (event-driven on marks change).
• Current suggestion actions (event-driven on current suggestion change).
• Automatically return the prompt when narrowed down to a single suggestion.