Struct MotionSpec 

pub struct MotionSpec {
    pub jump: bool,
    pub exclusive: bool,
    pub curswant: CurswantEffect,
    pub apply: Arc<dyn Fn(&MotionContext<'_>) -> GrammarResult<MotionResult> + Send + Sync>,
    pub args_schema: Vec<ArgSpec>,
}

A registered motion: its evaluator plus the vim properties the dispatcher and host need without running it.

Registered through CommandRegistry::register_motion (or CommandRegistry::register_plugin_motion). The dispatcher runs apply for a bare motion (the cursor moves to the result) and for an operator target (the span is cursor..result, shaped by exclusive and the result’s linewise).

Examples

A motion that jumps to the end of the buffer (a simplified G):

use std::sync::Arc;
use lattice_core::{BufferId, Document};
use lattice_grammar::{
    CancellationToken, CommandInvocation, CommandRegistry, CurswantEffect, Effect, MotionSpec,
    execute,
};
use lattice_grammar::registry::MotionResult;
use lattice_protocol::position::Position;

let mut registry = CommandRegistry::new();
let id = registry.register_motion(
    "motion:buffer-end",
    "Move to the start of the last line.",
    MotionSpec {
        jump: true,
        exclusive: false,
        curswant: CurswantEffect::default(),
        args_schema: vec![],
        apply: Arc::new(|ctx| {
            let last = ctx.buffer.content_line_count().saturating_sub(1);
            Ok(MotionResult { target: Position::new(last, 0), ..Default::default() })
        }),
    },
);
assert!(registry.motion_is_jump(id.0));

let mut doc = Document::from_text("one\ntwo\nthree");
let effect = execute(
    &registry,
    &mut doc,
    BufferId(0),
    Position::ZERO,
    CommandInvocation::of(id.0),
    &CancellationToken::never(),
)
.unwrap();
assert!(matches!(effect, Effect::CursorMove(p) if p == Position::new(2, 0)));

Fields

jump: bool

A vim jump: the host records the origin in position history (so <C-o> returns) and opens folds at the destination. Read through CommandRegistry::motion_is_jump.

exclusive: bool

Whether the motion’s end position is excluded from an operator’s span (w, b, 0 are exclusive; e, f, $ are inclusive). A MotionResult::exclusive overrides it per invocation.

curswant: CurswantEffect

VM.3g-1: this motion’s effect on the goal column. See CurswantEffect.

apply: Arc<dyn Fn(&MotionContext<'_>) -> GrammarResult<MotionResult> + Send + Sync>

The evaluator. Pure: reads the MotionContext, returns where to go.

args_schema: Vec<ArgSpec>

Per-positional-argument metadata (DESIGN.md §B.1). Empty for motions without args (the common case).

Trait Implementations

impl Clone for MotionSpec

fn clone(&self) -> MotionSpec

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MotionSpec

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.