go-elastictable

Go command line tables with elastic column resizing to adapt terminal width.

Approach

Naive algorithms simply take width-of-table/width-of-terminal and apply a uniform factor to grow/shrink the columns. This results in shoddy output, small columns become worse when wrapped.

This library optimizes for visual balance by doing the following:

• Closely pack wrapped lines:

  # don't:
  | don't waste whitespace in the second |
  | line                                 |
  
  # do:
  | when wrapping a column |
  | try to pack the lines  |
  | as closely as possible |
  

• Balance row heights:

  # don't:
  | COL-1       | COL-2       | COL-3       |
  +-------------+-------------+-------------+
  | small col   | small col   | really big  |
  |             |             | column that |
  |             |             | spans many  |
  |             |             | rows        |
  
  # do:
  | COL-1 | COL-2 | COL-3                   |
  +-------+-------+-------------------------+
  | small | small | really big column that  |
  | col   | col   | spans many rows         |
  

• Number of lines depends on wrapping behavior and is hard to predict in advance. So instead of fully computing expensive re-wraps for every pass, it rather just guesses the number of lines using simple rune widths. This works well in most cases, except there will be some trade-offs in certain scenarios.

Compatibility Note

This library is currently under active development. Please use a dependency manager (like godep) to pin specific commit versions.