Tab expansion support.

src/main.rs

@@ -24,6 +24,7 @@ mod decorations;
 mod diff;
 mod line_range;
 mod output;
+mod preprocessor;
 mod printer;
 mod style;
 mod terminal;

src/preprocessor.rs

@@ -0,0 +1,34 @@
+use console::AnsiCodeIterator;
+
+/// Expand tabs like an ANSI-enabled expand(1).
+pub fn expand(line: &str, width: usize, cursor: &mut usize) -> String {
+    let mut buffer = String::with_capacity(line.len() * 2);
+
+    for chunk in AnsiCodeIterator::new(line) {
+        match chunk {
+            (text, true) => buffer.push_str(text),
+            (mut text, false) => {
+                while let Some(index) = text.find('\t') {
+                    // Add previous text.
+                    if index > 0 {
+                        *cursor += index;
+                        buffer.push_str(&text[0..index]);
+                    }
+
+                    // Add tab.
+                    let spaces = width - (*cursor % width);
+                    *cursor += spaces;
+                    buffer.push_str(&*" ".repeat(spaces));
+
+                    // Next.
+                    text = &text[index + 1..text.len()];
+                }
+
+                *cursor += text.len();
+                buffer.push_str(text);
+            }
+        }
+    }
+
+    buffer
+}

src/printer.rs

@@ -16,6 +16,7 @@ use decorations::{Decoration, GridBorderDecoration, LineChangesDecoration, LineN
 use diff::get_git_diff;
 use diff::LineChanges;
 use errors::*;
+use preprocessor::expand;
 use style::OutputWrap;
 use terminal::{as_terminal_escaped, to_ansi_color};
 
@@ -152,6 +153,14 @@ impl<'a> InteractivePrinter<'a> {
 
         Ok(())
     }
+
+    fn preprocess(&self, text: &str, cursor: &mut usize) -> String {
+        if self.config.tab_width > 0 {
+            expand(text, self.config.tab_width, cursor)
+        } else {
+            text.to_string()
+        }
+    }
 }
 
 impl<'a> Printer for InteractivePrinter<'a> {
@@ -204,7 +213,7 @@ impl<'a> Printer for InteractivePrinter<'a> {
         line_number: usize,
         line_buffer: &[u8],
     ) -> Result<()> {
-        let line = String::from_utf8_lossy(&line_buffer);
+        let line = String::from_utf8_lossy(&line_buffer).to_string();
         let regions = self.highlighter.highlight(line.as_ref());
 
         if out_of_range {
@@ -213,6 +222,7 @@ impl<'a> Printer for InteractivePrinter<'a> {
 
         let mut cursor: usize = 0;
         let mut cursor_max: usize = self.config.term_width;
+        let mut cursor_total: usize = 0;
         let mut panel_wrap: Option<String> = None;
 
         // Line decorations.
@@ -234,19 +244,14 @@ impl<'a> Printer for InteractivePrinter<'a> {
             let true_color = self.config.true_color;
             let colored_output = self.config.colored_output;
 
-            write!(
-                handle,
-                "{}",
-                regions
-                    .iter()
-                    .map(|&(style, text)| as_terminal_escaped(
-                        style,
-                        text,
-                        true_color,
-                        colored_output,
-                    )).collect::<Vec<_>>()
-                    .join("")
-            )?;
+            for &(style, region) in regions.iter() {
+                let text = &*self.preprocess(region, &mut cursor_total);
+                write!(
+                    handle,
+                    "{}",
+                    as_terminal_escaped(style, &*text, true_color, colored_output,)
+                )?;
+            }
 
             if line.bytes().next_back() != Some(b'\n') {
                 write!(handle, "\n")?;
@@ -273,7 +278,11 @@ impl<'a> Printer for InteractivePrinter<'a> {
 
                         // Regular text.
                         (text, false) => {
-                            let text = text.trim_right_matches(|c| c == '\r' || c == '\n');
+                            let text = self.preprocess(
+                                text.trim_right_matches(|c| c == '\r' || c == '\n'),
+                                &mut cursor_total,
+                            );
+
                             let mut chars = text.chars();
                             let mut remaining = text.chars().count();
 

tests/snapshots/generate_snapshots.py

@@ -10,16 +10,27 @@ def generate_snapshots():
 
     for num in range(len(single_styles)):
         for grouped in itertools.combinations(single_styles, num + 1):
-            generate_snapshot(",".join(grouped))
+            generate_style_snapshot(",".join(grouped))
 
     for style in collective_styles:
-        generate_snapshot(style)
-
-def generate_snapshot(option):
-    command = "../../target/debug/bat --style={0} sample.rs > output/{0}.snapshot.txt".format(
-        option
+        generate_style_snapshot(style)
+
+    generate_snapshot("tabs_passthrough", "--tabs=0 --style=full --wrap=never")
+    generate_snapshot("tabs_passthrough_wrapped", "--tabs=0 --style=full --wrap=character")
+    generate_snapshot("tabs_4", "--tabs=4 --style=full --wrap=never")
+    generate_snapshot("tabs_4_wrapped", "--tabs=4 --style=full --wrap=character")
+    generate_snapshot("tabs_8", "--tabs=8 --style=full --wrap=never")
+    generate_snapshot("tabs_8_wrapped", "--tabs=8 --style=full --wrap=character")
+
+def generate_style_snapshot(style):
+    generate_snapshot(style.replace(",","_"), "--style={}".format(style))
+
+def generate_snapshot(name, arguments):
+    command = "../../target/debug/bat --decorations=always {1} sample.rs > output/{0}.snapshot.txt".format(
+        name,
+        arguments
     )
-    print("generating snapshot for {}".format(option))
+    print("generating snapshot for {}".format(name))
     subprocess.call(command, shell=True)
 
 def build_bat():

tests/snapshots/output/changes.snapshot.txt

@@ -16,7 +16,21 @@ _ fn main() {
   fn area(rectangle: &Rectangle) -> u32 {
       rectangle.width * rectangle.height
   }
-+ 
+  
 + fn perimeter(rectangle: &Rectangle) -> u32 {
 +     (rectangle.width + rectangle.height) * 2
 + }
++ 
+  // Tab alignment:
+  /*
+          Indent
+          1       2       3       4
+  1       ?
+  22      ?
+  333     ?
+  4444    ?
+  55555   ?
+  666666  ?
+  7777777 ?
+  88888888        ?
+~ */

tests/snapshots/output/changes,grid.snapshot.txt → tests/snapshots/output/changes_grid.snapshot.txt

@@ -16,8 +16,22 @@ _ │ fn main() {
   │ fn area(rectangle: &Rectangle) -> u32 {
   │     rectangle.width * rectangle.height
   │ }
-+ │ 
+  │ 
 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
 + │     (rectangle.width + rectangle.height) * 2
 + │ }
++ │ 
+  │ // Tab alignment:
+  │ /*
+  │         Indent
+  │         1       2       3       4
+  │ 1       ?
+  │ 22      ?
+  │ 333     ?
+  │ 4444    ?
+  │ 55555   ?
+  │ 666666  ?
+  │ 7777777 ?
+  │ 88888888        ?
+~ │ */
 ──┴─────────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes,grid,header.snapshot.txt → tests/snapshots/output/changes_grid_header.snapshot.txt

@@ -19,8 +19,22 @@ _ │ fn main() {
   │ fn area(rectangle: &Rectangle) -> u32 {
   │     rectangle.width * rectangle.height
   │ }
-+ │ 
+  │ 
 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
 + │     (rectangle.width + rectangle.height) * 2
 + │ }
++ │ 
+  │ // Tab alignment:
+  │ /*
+  │         Indent
+  │         1       2       3       4
+  │ 1       ?
+  │ 22      ?
+  │ 333     ?
+  │ 4444    ?
+  │ 55555   ?
+  │ 666666  ?
+  │ 7777777 ?
+  │ 88888888        ?
+~ │ */
 ──┴─────────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes_grid_header_numbers.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "�����"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes,grid,numbers.snapshot.txt → tests/snapshots/output/changes_grid_numbers.snapshot.txt

@@ -16,8 +16,22 @@
   16   │ fn area(rectangle: &Rectangle) -> u32 {
   17   │     rectangle.width * rectangle.height
   18   │ }
-  19 + │ 
+  19   │ 
   20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 + │     (rectangle.width + rectangle.height) * 2
   22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
 ───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes,header.snapshot.txt → tests/snapshots/output/changes_header.snapshot.txt

@@ -17,7 +17,21 @@ _ fn main() {
   fn area(rectangle: &Rectangle) -> u32 {
       rectangle.width * rectangle.height
   }
-+ 
+  
 + fn perimeter(rectangle: &Rectangle) -> u32 {
 +     (rectangle.width + rectangle.height) * 2
 + }
++ 
+  // Tab alignment:
+  /*
+          Indent
+          1       2       3       4
+  1       ?
+  22      ?
+  333     ?
+  4444    ?
+  55555   ?
+  666666  ?
+  7777777 ?
+  88888888        ?
+~ */

tests/snapshots/output/changes,header,numbers.snapshot.txt → tests/snapshots/output/changes_header_numbers.snapshot.txt

@@ -17,7 +17,21 @@
   16   fn area(rectangle: &Rectangle) -> u32 {
   17       rectangle.width * rectangle.height
   18   }
-  19 + 
+  19   
   20 + fn perimeter(rectangle: &Rectangle) -> u32 {
   21 +     (rectangle.width + rectangle.height) * 2
   22 + }
+  23 + 
+  24   // Tab alignment:
+  25   /*
+  26           Indent
+  27           1       2       3       4
+  28   1       ?
+  29   22      ?
+  30   333     ?
+  31   4444    ?
+  32   55555   ?
+  33   666666  ?
+  34   7777777 ?
+  35   88888888        ?
+  36 ~ */

tests/snapshots/output/changes,numbers.snapshot.txt → tests/snapshots/output/changes_numbers.snapshot.txt

@@ -16,7 +16,21 @@
   16   fn area(rectangle: &Rectangle) -> u32 {
   17       rectangle.width * rectangle.height
   18   }
-  19 + 
+  19   
   20 + fn perimeter(rectangle: &Rectangle) -> u32 {
   21 +     (rectangle.width + rectangle.height) * 2
   22 + }
+  23 + 
+  24   // Tab alignment:
+  25   /*
+  26           Indent
+  27           1       2       3       4
+  28   1       ?
+  29   22      ?
+  30   333     ?
+  31   4444    ?
+  32   55555   ?
+  33   666666  ?
+  34   7777777 ?
+  35   88888888        ?
+  36 ~ */

tests/snapshots/output/full.snapshot.txt

@@ -19,8 +19,22 @@
   16   │ fn area(rectangle: &Rectangle) -> u32 {
   17   │     rectangle.width * rectangle.height
   18   │ }
-  19 + │ 
+  19   │ 
   20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 + │     (rectangle.width + rectangle.height) * 2
   22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
 ───────┴────────────────────────────────────────────────────────────────────────