bench: Use a OnceCell to avoid recompiling the en_US dictionary

Now that the Dictionary is Sync (see the parent commit), we can use
brunch's default benches macro to improve the bench output.

bench/Cargo.toml

@@ -8,3 +8,4 @@ rust-version = "1.66"
 [dependencies]
 spellbook = { path = "../" }
 brunch = "0.5"
+once_cell = "1"

bench/src/main.rs

@@ -1,43 +1,38 @@
 use std::hint::black_box;
 
 use brunch::Bench;
+use once_cell::sync::OnceCell;
 use spellbook::Dictionary;
 
 const EN_US_DIC: &str = include_str!("../../vendor/en_US/en_US.dic");
 const EN_US_AFF: &str = include_str!("../../vendor/en_US/en_US.aff");
 
 const SAMPLES: u32 = 500_000;
 
-fn main() {
-    let dict = Dictionary::compile(EN_US_AFF, EN_US_DIC).unwrap();
-
-    eprintln!("Starting benchmarks...");
-    eprintln!();
-    let now = std::time::Instant::now();
-    brunch::benches!(
-        inline:
-
-        // Compilation
-        Bench::new("Compile en_US")
-            .run(|| Dictionary::compile(black_box(EN_US_AFF), black_box(EN_US_DIC))),
-        Bench::spacer(),
-
-        // Checking
-        Bench::new("In-dictionary word (\"drink\")")
-            .with_samples(SAMPLES)
-            .run(|| dict.check(black_box("drink"))),
-        Bench::new("Word with a suffix (\"drinkable\")")
-            .with_samples(SAMPLES)
-            .run(|| dict.check(black_box("drinkable"))),
-        Bench::new("Multi-affix (\"undrinkable\")")
-            .with_samples(SAMPLES)
-            .run(|| dict.check(black_box("undrinkable"))),
-        Bench::new("Incorrect prefix (\"undrink\")")
-            .with_samples(SAMPLES)
-            .run(|| dict.check(black_box("undrink"))),
-        Bench::new("Breaks (\"light-weight-like\")")
-            .with_samples(SAMPLES)
-            .run(|| dict.check(black_box("light-weight-like"))),
-    );
-    eprintln!("Finished in {:.1}s", now.elapsed().as_secs_f64());
+fn en_us() -> &'static Dictionary {
+    static EN_US: OnceCell<Dictionary> = OnceCell::new();
+    EN_US.get_or_init(|| Dictionary::compile(EN_US_AFF, EN_US_DIC).unwrap())
 }
+
+brunch::benches!(
+    // Compilation
+    Bench::new("Compile en_US")
+        .run(|| Dictionary::compile(black_box(EN_US_AFF), black_box(EN_US_DIC))),
+    Bench::spacer(),
+    // Checking
+    Bench::new("In-dictionary word (\"drink\")")
+        .with_samples(SAMPLES)
+        .run_seeded_with(en_us, |dict| dict.check(black_box("drink"))),
+    Bench::new("Word with a suffix (\"drinkable\")")
+        .with_samples(SAMPLES)
+        .run_seeded_with(en_us, |dict| dict.check(black_box("drinkable"))),
+    Bench::new("Multi-affix (\"undrinkable\")")
+        .with_samples(SAMPLES)
+        .run_seeded_with(en_us, |dict| dict.check(black_box("undrinkable"))),
+    Bench::new("Incorrect prefix (\"undrink\")")
+        .with_samples(SAMPLES)
+        .run_seeded_with(en_us, |dict| dict.check(black_box("undrink"))),
+    Bench::new("Breaks (\"light-weight-like\")")
+        .with_samples(SAMPLES)
+        .run_seeded_with(en_us, |dict| dict.check(black_box("light-weight-like"))),
+);