Merge pull request #234 from mgeisler/optimal-fit-algorithm

Introduce wrapping using an optimal-fit algorithm

Cargo.toml

@@ -31,6 +31,7 @@ name = "linear"
 harness = false
 
 [dependencies]
+smawk = "0.3"
 unicode-width = "0.1"
 terminal_size = { version = "0.1", optional = true }
 hyphenation = { version = "0.8", optional = true, features = ["embed_en-us"] }

benches/linear.rs

@@ -23,12 +23,28 @@ pub fn benchmark(c: &mut Criterion) {
     let mut group = c.benchmark_group("String lengths");
     for length in [100, 200, 400, 800, 1600, 3200, 6400].iter() {
         let text = lorem_ipsum(*length);
-        let options = textwrap::Options::new(LINE_LENGTH);
-        group.bench_with_input(BenchmarkId::new("fill", length), &text, |b, text| {
-            b.iter(|| textwrap::fill(text, &options));
-        });
+        let options = textwrap::Options::new(LINE_LENGTH)
+            .wrap_algorithm(textwrap::core::WrapAlgorithm::OptimalFit);
+        group.bench_with_input(
+            BenchmarkId::new("fill_optimal_fit", length),
+            &text,
+            |b, text| {
+                b.iter(|| textwrap::fill(text, &options));
+            },
+        );
+
+        let options = textwrap::Options::new(LINE_LENGTH)
+            .wrap_algorithm(textwrap::core::WrapAlgorithm::FirstFit);
+        group.bench_with_input(
+            BenchmarkId::new("fill_first_fit", length),
+            &text,
+            |b, text| {
+                b.iter(|| textwrap::fill(text, &options));
+            },
+        );
 
-        let options: textwrap::Options = options.splitter(Box::new(textwrap::HyphenSplitter));
+        let options: textwrap::Options =
+            textwrap::Options::new(LINE_LENGTH).splitter(Box::new(textwrap::HyphenSplitter));
         group.bench_with_input(BenchmarkId::new("fill_boxed", length), &text, |b, text| {
             b.iter(|| textwrap::fill(text, &options));
         });

examples/interactive.rs

@@ -19,6 +19,7 @@ mod unix_only {
     use termion::raw::{IntoRawMode, RawTerminal};
     use termion::screen::AlternateScreen;
     use termion::{color, cursor, style};
+    use textwrap::core::WrapAlgorithm::{FirstFit, OptimalFit};
     use textwrap::{wrap, HyphenSplitter, NoHyphenation, Options, WordSplitter};
 
     #[cfg(feature = "hyphenation")]
@@ -101,6 +102,16 @@ mod unix_only {
         )?;
         left_row += 1;
 
+        write!(
+            stdout,
+            "{}- algorithm: {}{:?}{} (toggle with Ctrl-o)",
+            cursor::Goto(left_col, left_row),
+            style::Bold,
+            options.wrap_algorithm,
+            style::Reset,
+        )?;
+        left_row += 1;
+
         let now = std::time::Instant::now();
         let mut lines = wrap(text, options);
         let elapsed = now.elapsed();
@@ -232,6 +243,12 @@ mod unix_only {
                 Key::Left => options.width = options.width.saturating_sub(1),
                 Key::Right => options.width = options.width.saturating_add(1),
                 Key::Ctrl('b') => options.break_words = !options.break_words,
+                Key::Ctrl('o') => {
+                    options.wrap_algorithm = match options.wrap_algorithm {
+                        OptimalFit => FirstFit,
+                        FirstFit => OptimalFit,
+                    }
+                }
                 Key::Ctrl('s') => {
                     let idx = idx_iter.next().unwrap();
                     std::mem::swap(&mut options.splitter, &mut splitters[idx]);