Crate tabwriter

This crate provides an implementation of elastic tabstops. It is a minimal port of Go’s tabwriter package. Namely, its main mode of operation is to wrap a Writer and implement elastic tabstops for the text written to the wrapped Writer.

This package is also bundled with a program, tabwriter, that exposes this functionality at the command line.

Here’s an example that shows basic alignment:

use std::io::Write;
use tabwriter::TabWriter;

let mut tw = TabWriter::new(vec![]);
write!(&mut tw, "
Bruce Springsteen\tBorn to Run
Bob Seger\tNight Moves
Metallica\tBlack
The Boss\tDarkness on the Edge of Town
").unwrap();
tw.flush().unwrap();

let written = String::from_utf8(tw.into_inner().unwrap()).unwrap();
assert_eq!(&*written, "
Bruce Springsteen  Born to Run
Bob Seger          Night Moves
Metallica          Black
The Boss           Darkness on the Edge of Town
");

Note that flush must be called or else TabWriter may never write anything. This is because elastic tabstops requires knowing about future lines in order to align output. More precisely, all text considered in a single alignment must fit into memory.

Here’s another example that demonstrates how only contiguous columns are aligned:

use std::io::Write;
use tabwriter::TabWriter;

let mut tw = TabWriter::new(vec![]).padding(1);
write!(&mut tw, "
fn foobar() {{
   let mut x = 1+1;\t// addition
   x += 1;\t// increment in place
   let y = x * x * x * x;\t// multiply!

   y += 1;\t// this is another group
   y += 2 * 2;\t// that is separately aligned
}}
").unwrap();
tw.flush().unwrap();

let written = String::from_utf8(tw.into_inner().unwrap()).unwrap();
assert_eq!(&*written, "
fn foobar() {
   let mut x = 1+1;       // addition
   x += 1;                // increment in place
   let y = x * x * x * x; // multiply!

   y += 1;     // this is another group
   y += 2 * 2; // that is separately aligned
}
");

Structs

• IntoInnerError
  An error returned by into_inner.
• TabWriter
  TabWriter wraps an arbitrary writer and aligns tabbed output.

Enums

• Alignment
  Alignment represents how a TabWriter should align text within its cell.