Struct MotionEngine 

pub struct MotionEngine;

Motion calculation engine.

Provides pure calculations for cursor positions without modifying any state. This is the “mechanism” that modules use to implement motion commands.

Example

use reovim_kernel::api::v1::*;

let buffer = Buffer::from_string("hello world");
let cursor = Cursor::new(Position::new(0, 0));

let new_pos = MotionEngine::calculate(
    &buffer,
    &cursor,
    Motion::Char(Direction::Forward),
    1,
);

assert_eq!(new_pos, Some(Position::new(0, 1)));

Implementations

impl MotionEngine

pub fn calculate( buffer: &Buffer, cursor: &Cursor, motion: Motion, count: usize, ) -> Option<Position>

Calculate new position after applying a motion.

Returns None if the motion is invalid or impossible.

Arguments

• buffer - The buffer to calculate motion in
• cursor - Current cursor state (includes position and preferred column)
• motion - The motion to apply
• count - Number of times to apply the motion (minimum 1)

pub fn calculate_with_desired_col( buffer: &Buffer, cursor: &Cursor, motion: Motion, count: usize, ) -> (Option<Position>, Option<usize>)

Calculate new position and desired column after applying a motion.

This variant is useful for vertical motions where the cursor should try to maintain its horizontal position across lines of different lengths.

Returns (new_position, new_desired_column)