Module motion 

High-level editor navigation logic (motions).

This module is intentionally UI-agnostic and depends only on core editor types like TextBuffer and Pos. It provides a stable API to build Vim-like behavior on top of (e.g. w, gg, G, 0, $, etc.).

Design goals:

• Keep motions deterministic and side-effect-free.
• Keep indexing consistent with redox-core: Pos { line, col } where col is in char units (Ropey model).
• Centralize motion semantics here so frontends (TUI/GUI) only project the resulting document cursor into their own viewport/cell coordinate systems.

Notes:

• Word motions here currently use TextBuffer’s existing word helpers (word_start_before, word_end_after), which in turn use buffer::util::is_word_char.
• Many Vim details (e.g. inclusive/exclusive, operator-pending behavior, iskeyword, sentence/paragraph motions) can be layered later without changing the frontend.

This file defines:

• Motion enum: the set of supported navigation intents.
• apply_motion / apply_motion_n: apply motions to a cursor position.

Modules

helpers

Convenience helpers for motions that take a count.

Enums

Motion

A navigation intent (motion) that transforms a document cursor.

Functions

apply_motion

Apply a single Motion to a given cursor position.

apply_motion_n

Apply a motion count times (Vim-style numeric prefix).