Make the Rust implementation the only one: crate at the root, Go tree removed

examples/bench.rs

@@ -0,0 +1,58 @@
+//! In-process benchmarks mirroring the Go `go test -bench` suite
+//! (internal/tui/bench_test.go, internal/treemap/treemap_test.go):
+//!
+//!     cargo run --release --example bench
+//!
+//! Each case runs for ~2 s after a warm-up and reports the mean time per op.
+
+use mapsize::treemap::{self, Direction, Item, Rect};
+use mapsize::tui::bench::{big_tree, BenchModel};
+use std::hint::black_box;
+use std::sync::{Arc, RwLock};
+use std::time::{Duration, Instant};
+
+fn bench<R>(name: &str, mut f: impl FnMut(u64) -> R) {
+    black_box(f(0));
+    let budget = Duration::from_secs(2);
+    let start = Instant::now();
+    let mut n = 0u64;
+    while start.elapsed() < budget {
+        black_box(f(n));
+        n += 1;
+    }
+    let per = start.elapsed() / n as u32;
+    println!("{name:<40} {n:>8} ops  {per:>12.2?}/op");
+}
+
+fn main() {
+    let items: Vec<Item> = (0..300).map(|i| Item { id: i, size: (1 + i * i) as f64 }).collect();
+    let bounds = Rect { x: 0, y: 0, w: 200, h: 60 };
+    bench("treemap/Squarify(300)", |_| {
+        black_box(treemap::squarify(black_box(&items), bounds));
+    });
+    let blocks = treemap::squarify(&items, bounds);
+    bench("treemap/Neighbour(300)", |_| {
+        black_box(treemap::neighbour(black_box(&blocks), 150, Direction::Right));
+    });
+
+    let t0 = Instant::now();
+    let tree = Arc::new(RwLock::new(big_tree()));
+    println!("big tree: {} nodes built in {:.2?}", tree.read().unwrap().len(), t0.elapsed());
+
+    let mut m = BenchModel::new(tree.clone(), 200, 60);
+    bench("tui/BigColdFrame", |_| m.cold_frame());
+    let mut m = BenchModel::new(tree.clone(), 200, 60);
+    m.cold_frame();
+    bench("tui/BigResize", |i| m.resize(150 + (i % 100) as u16, 40 + (i % 30) as u16));
+    let mut m = BenchModel::new(tree.clone(), 200, 60);
+    m.zoom_to_child_named(b"flat");
+    bench("tui/BigFlatDirCold", |_| m.cold_frame());
+    let mut m = BenchModel::new(tree.clone(), 200, 60);
+    m.cold_frame();
+    let keys = ["right", "down", "left", "up"];
+    bench("tui/BigNavigate", |i| m.key(keys[i as usize % 4]));
+    for q in ["size > 1MB", "*.dat AND size > 500k", "path contains sub3"] {
+        let mut m = BenchModel::new(tree.clone(), 200, 60);
+        bench(&format!("tui/BigFilter/{q}"), |_| m.apply_filter(q));
+    }
+}