SpeedRect

Quick key bindings and other tools for Emacs' rectangle-mark-mode.

SpeedRect is a small Emacs package that provides convenient "modal" key bindings and other tools while in rectangle-mark-mode (C-x SPC, or C-M-mouse1 drag, by default).

Features

• Single-key bindings for all the basic rectangle functions: open, insert string, kill, delete, clear, copy, yank.
• Restarts by default, so you can continue rectangle actions.
• Ability to restore the last rectangle's position, which gets auto-saved.
• Additional command to invert the deletion, i.e. delete the unmarked columns in affected rows, keeping only the marked rectangle on those lines.
• Change your mind and start a new rectangle from point.
• Exposes a useful command (SPC) to delete whitespace from the left rectangle boundary.
• Column shift: slide the marked rectangle position left or right, 1 (hold shift) or 5 (meta-shift) columns at a time (or any number of columns, with a numerical prefix).
• Two-way interaction with Calc: send sums or tables of data into calc, and yank processed matrix data back into the rectangle from the top of calc's stack.
• Quickly add multiple cursors on each line of the current rectangle.
• A useful help page (?).

News

• v0.5: New command f to fill (wrap) text in the rectangle. Use prefix for fill width (defaults to rectangle width).
• v0.4: New command x for moving around rectangle corners, and M for placing multiple-cursors on each line at the current column.

Installation

Just download, add to path, and arrange to (require 'speedrect). For users of use-package:

(use-package speedrect
  :load-path "~/code/emacs/speedrect") ; or wherever

Or, with use-package and straight:

(use-package speedrect
  :straight (speedrect :type git :host github :repo "jdtsmith/speedrect"))

Usage

Start rectangle-mark-mode as usual (C-x SPC, by default). Hit ? to summon a help buffer of available key bindings. By default most commands restart rectangle-mark-mode; q (or any other non-shortcut command) to exit. If you'd prefer speedrect commands not to continue in this way, set speedrect-continue=nil.

Hints

A rectangle is just a region (point and mark), specially interpreted. While marking rectangles, you can use x to cycle point among any of the rectangles four corners. This is useful to make changes to the appropriate side of the selected region.

Use calc, it's super-powerful...

Using Calc

Calc is an ancient and powerful calculator in emacs with many capabilities, including operating on matrix data. In addition to simple sums, SpeedRect offers powerful two-way communication with calc for sending in and yanking out columns of numerical data:

1. It can send columns of numbers to calc as a matrix (2D array of numbers). Once in calc, you can operate on those numbers using a wide array of operations. Many things "just work" on matrices (e.g. 1 + will add one to all the numbers). Others can easily be mapped over matrix elements (e.g. try v M Q to map sqrt over all elements). You can combine columns, change their order, and much more.
2. Once you have something you're happy with at the top of calc's stack (at the bottom of the *Calculator* buffer, entry numbered 1:), you can:
   • hit q (or other window navigation) to return to your original buffer (where rectangle-mark-mode will still be active),
   • adjust the position of your rectangle if needed (S-left/right and/or x is useful for this; a zero-width rectangle is fine), and
   • hit m to yank the latest matrix from calc into the buffer (if it has the right number of rows), replacing the marked rectangle.

You don't have to be in the same mark-rectangle-mode session to yank a matrix from calc. As long as the height of your rectangle matches the number of matrix rows, it will just work. So you can start in one buffer, accumulate a matrix, manipulate it, switch to another buffer, and yank it there.

Note: what you see is what you get in calc. The matrix will be yanked exactly as it appears. v [ and v , will remove the brackets and commas for a cleaner appearance. v > will right align numbers. While v . is convenient for shortening long entries, you must undo it before yanking. d f will let you set the number of digits after the decimal. And many more options.

Key Listing

SpeedRect Rectangle Mark Mode Commands
============================================================================

Insertion:

  [o] open      open rectangle with tabs/spaces, shifting text right
  [t] string    replace rectangle with string

Killing:

  [k] kill      kill and save rectangle for yanking
  [d] delete    kill rectangle without saving
  [SPC] del-ws  delete all whitespace, starting from left column
  [c] clear     clear rectangle area by overwriting with spaces
  [r] rest      delete the rest of the columns, keeping the marked rectangle

Copy/Yank:

  [w] copy      copy rectangle for future yanking
  [y] yank      yank rectangle, inserting at point

Shift Rectangle (can use numeric prefixes):

  [S-left]      move the rectangle left
  [S-right]     move the rectangle right
  [S-up]        move the rectangle up
  [S-down]      move the rectangle down
  [M-S-left]    move the rectangle left 5 columns
  [M-S-right]   move the rectangle right 5 columns
  [M-S-up]      move the rectangle up 5 columns
  [M-S-down]    move the rectangle down 5 lines

Change Rectangle:

  [x] corners   move point around corners of the rectangle
  [n] new       start a new rectangle from this location
  [l] last      restore the last used rectangle, if possible

Numerical:

  [N] numbers   fill the rectangle with numbers (prefix to set start)
  [#] grab      grab the rectangle as a matrix in calc
  [_] across    sum across rows and grab result in calc as a vector
  [:] down      sum down the columns and grab result in calc
  [m] yank-mat  yank matrix from top of calc stack, overwriting selected rect

Etc:

  [f] fill text within rectangle (prefix to prompt fill width)
  [M] multiple-cursors   add cursors at current column
  [?] help      view this Help buffer
  [q] quit      exit rectangle-mark-mode

Related packages

• phi-rectangle

Thanks

Contributors of ideas from this discussion