Add tab_width support

benchmarks/Cargo.toml

@@ -23,6 +23,11 @@ name = "unfill"
 harness = false
 path = "unfill.rs"
 
+[[bench]]
+name = "display_width"
+harness = false
+path = "display_width.rs"
+
 [dependencies]
 textwrap = { path = "../", features = ["hyphenation"] }
 

benchmarks/display_width.rs

@@ -0,0 +1,26 @@
+use criterion::{criterion_group, criterion_main, Criterion};
+
+pub fn benchmark(c: &mut Criterion) {
+    let words_per_line = [
+        5, 10, 15, 5, 5, 10, 5, 5, 5, 10, // 10 lines
+        10, 10, 5, 5, 5, 5, 15, 10, 5, 5, // 20 lines
+        10, 5, 5, 5, 15, 10, 10, 5, 5, 5, // 30 lines
+        15, 5, 5, 10, 5, 5, 5, 15, 5, 10, // 40 lines
+        5, 15, 5, 5, 15, 5, 10, 10, 5, 5, // 50 lines
+    ];
+    let mut text = String::new();
+    for (line_no, word_count) in words_per_line.iter().enumerate() {
+        text.push_str("\t\t\t");
+        text.push_str(&lipsum::lipsum_words_from_seed(*word_count, line_no as u64));
+        text.push('\n');
+    }
+    text.push_str("\n\n\n\n");
+    assert_eq!(text.len(), 2800); // The size for reference.
+
+    c.bench_function("display_width", |b| {
+        b.iter(|| textwrap::core::display_width(&text, 2))
+    });
+}
+
+criterion_group!(benches, benchmark);
+criterion_main!(benches);

examples/wasm/src/lib.rs

@@ -152,7 +152,7 @@ impl textwrap::core::Fragment for CanvasWord<'_> {
     }
 
     #[inline]
-    fn whitespace_width(&self) -> f64 {
+    fn whitespace_width(&self, _: u8) -> f64 {
         self.whitespace_width
     }
 
@@ -351,7 +351,7 @@ pub fn draw_wrapped_text(
     let mut lineno = 0;
     for line in text.split('\n') {
         let words = word_separator.find_words(line);
-        let split_words = split_words(words, &word_splitter);
+        let split_words = split_words(words, &word_splitter, 0);
 
         let canvas_words = split_words
             .flat_map(|word| {
@@ -366,10 +366,10 @@ pub fn draw_wrapped_text(
 
         let line_lengths = [options.width];
         let wrapped_words = match options.wrap_algorithm {
-            WasmWrapAlgorithm::FirstFit => wrap_first_fit(&canvas_words, &line_lengths),
+            WasmWrapAlgorithm::FirstFit => wrap_first_fit(&canvas_words, &line_lengths, 0),
             WasmWrapAlgorithm::OptimalFit => {
                 let penalties = options.penalties.into();
-                wrap_optimal_fit(&canvas_words, &line_lengths, &penalties).unwrap()
+                wrap_optimal_fit(&canvas_words, &line_lengths, 0, &penalties).unwrap()
             }
             _ => Err("WasmOptions has an invalid wrap_algorithm field")?,
         };

fuzz/fuzz_targets/wrap_first_fit.rs

@@ -14,12 +14,12 @@ struct Word {
 #[rustfmt::skip]
 impl core::Fragment for Word {
     fn width(&self) -> f64 { self.width }
-    fn whitespace_width(&self) -> f64 { self.whitespace_width }
+    fn whitespace_width(&self, _: u8) -> f64 { self.whitespace_width }
     fn penalty_width(&self) -> f64 { self.penalty_width }
 }
 
 fuzz_target!(|input: (f64, Vec<Word>)| {
     let width = input.0;
     let words = input.1;
-    let _ = wrap_first_fit(&words, &[width]);
+    let _ = wrap_first_fit(&words, &[width], 0);
 });

fuzz/fuzz_targets/wrap_optimal_fit.rs

@@ -35,7 +35,7 @@ struct Word {
 #[rustfmt::skip]
 impl core::Fragment for Word {
     fn width(&self) -> f64 { self.width }
-    fn whitespace_width(&self) -> f64 { self.whitespace_width }
+    fn whitespace_width(&self, _: u8) -> f64 { self.whitespace_width }
     fn penalty_width(&self) -> f64 { self.penalty_width }
 }
 
@@ -57,5 +57,5 @@ fuzz_target!(|input: (usize, Vec<Word>, Penalties)| {
         }
     }
 
-    let _ = wrap_optimal_fit(&words, &[width as f64], &penalties);
+    let _ = wrap_optimal_fit(&words, &[width as f64], 0, &penalties);
 });

fuzz/fuzz_targets/wrap_optimal_fit_usize.rs

@@ -35,7 +35,7 @@ struct Word {
 #[rustfmt::skip]
 impl core::Fragment for Word {
     fn width(&self) -> f64 { self.width as f64 }
-    fn whitespace_width(&self) -> f64 { self.whitespace_width as f64 }
+    fn whitespace_width(&self, _: u8) -> f64 { self.whitespace_width as f64 }
     fn penalty_width(&self) -> f64 { self.penalty_width as f64 }
 }
 
@@ -45,5 +45,5 @@ fuzz_target!(|input: (usize, Vec<Word>, Penalties)| {
     let width = input.0;
     let words = input.1;
     let penalties = input.2.into();
-    let _ = wrap_optimal_fit(&words, &[width as f64], &penalties);
+    let _ = wrap_optimal_fit(&words, &[width as f64], 0, &penalties);
 });

src/columns.rs

@@ -1,7 +1,6 @@
 //! Functionality for wrapping text into columns.
 
-use crate::core::display_width;
-use crate::{wrap, Options};
+use crate::{core, wrap, Options};
 
 /// Wrap text into columns with a given total width.
 ///
@@ -23,9 +22,9 @@ use crate::{wrap, Options};
 /// # let columns = 2;
 /// # let options = textwrap::Options::new(80);
 /// let inner_width = options.width
-///     - textwrap::core::display_width(left_gap)
-///     - textwrap::core::display_width(right_gap)
-///     - textwrap::core::display_width(middle_gap) * (columns - 1);
+///     - textwrap::core::display_width(left_gap, options.tab_width)
+///     - textwrap::core::display_width(right_gap, options.tab_width)
+///     - textwrap::core::display_width(middle_gap, options.tab_width) * (columns - 1);
 /// let column_width = inner_width / columns;
 /// ```
 ///
@@ -74,6 +73,8 @@ where
     assert!(columns > 0);
 
     let mut options: Options = total_width_or_options.into();
+    let tab_width = options.tab_width;
+    let display_width = |text| core::display_width(text, tab_width);
 
     let inner_width = options
         .width
@@ -190,4 +191,21 @@ mod tests {
     fn wrap_columns_panic_with_zero_columns() {
         wrap_columns("", 0, 10, "", "", "");
     }
+
+    #[test]
+    fn wrap_columns_with_tabs() {
+        let options = Options::new(23).tab_width(4);
+
+        #[cfg(feature = "smawk")]
+        let expected = vec!["|hello     |is\tlong|", "|this      |yeah      |"];
+        #[cfg(all(not(feature = "smawk"), feature = "unicode-linebreak"))]
+        let expected = vec!["|hello     |long      |", "|this\tis|yeah      |"];
+        #[cfg(not(any(feature = "smawk", feature = "unicode-linebreak")))]
+        let expected = vec!["|hello\tt|\tlong  |", "|his\tis |\tyeah  |"];
+
+        assert_eq!(
+            wrap_columns("hello\tthis\tis\tlong\tyeah", 2, options, "|", "|", "|"),
+            expected
+        )
+    }
 }