General-Purpose TextMode Text Editor

Here's an idea which will hopefully become more than that as time passes.

Background

There is currently no command line text editor that follows the design principle of least surprise:

I can't fire up nano, or Vim (and i shudder to even think of installing emacs), and use ctrl+left or right to move between words; I can't hold shift and press End to select to the end of the line. If I want to do something that 'advanced', I'd have to learn Vim.

No thanks. I won't learn a completely different muscle-memory language for editing text files in one particular context (purely for political or historical reasons), when all these keyboard shortcuts work perfectly in every other editor I use (Eclipse, netbeans, notepad++, geany, gedit....).

The ctrl+arrow stuff is so standard, it's implemented in Android text-input boxes.

If we can have this functionality in our mobile phones, why not in our ssh sessions?

Nothing about text-mode text editing prevents this, so why hasn't it been invented yet?

So I'll invent it.

In all likelihood, this'll be a fork of nano.

Libraries

I'll most likely be using this keyboard input handling library, which claims to be able to capture ctrl-arrow keypresses.
Ncurses will still be able to provide text-based layout and things.

Design Document

Written in C, primarily for POSIX/UNIX systems (read:linux)
Portable!

Let's start listing features this text editor will have.

Display

Line numbers permanently along the left-hand side
Number of occurrences displayed when searching
Column number, word count displayed at bottom. Current line number highlighted (inverted) in line numbers.

Behaviour

WILL NOT be tabbed, or open >1 file simultaneously; dammit Jim, it's a text editor, not an IDE!
Will have syntax highlighting
- Using an existing language's syntax files (nano's or vim's will do), to reduce user learning overhead (and provide instant language support)
WILL highlight selected text with inverted colouring
WILL NOT support Vim keystroke emulation in any way; anyone who has taken the time and effort to learn vim probably still knows how to use the standard text-editing interface that everyone else has used for 15+ years.
- Also they'll always just be able to use Vim anyway, as Vim runs anywhere this will.
Corresponding bracket highlighting
Smooth scrolling
WILL NOT be able to start a new file inside the editor;
- Do that in the shell, then open that file for editing.
- Or start the editor with a non-existent filename as an argument.
typing any valid keys on the keyboar without a modifier key will insert/overwrite those characters at the current point
Will respect the decades-old insert/overwrite modes, switched with the Insert key
UNDO AND REDO! (how hard can it be to write a linked-list stack of textfile state, and add to it every time the user modifies the file?)

Possible/Future Extras

gpm-based mouse support???
File-menu style menu simulation, reachable by pressing alt or clicking (with mouse support) the top of the screen

Keyboard shortcuts

The idea is, you (or your fingers) should be able to guess all these. These are only a reminder so I know what I'll have to implement.

Navigating Text

Key	Action
left	move left one char
right	move right one char
up	move up one line
down	move down one line
Ctrl+left	move left one word
Ctrl+right	move right one word
Home	move to (non-whitespace) start of line
End	move to (non-whitespace) end of line
Ctrl+Home	move to start of file
Ctrl+End	move to end of file
Ctrl+F	find a string in the file
Ctrl+H	replace a string in the file (opens a small ncurses dialog)
F3	move to next occurrence
shift+F3, shift+n	move to previous occurrence
Ctrl+X	Cuts any selected text
Ctrl+C	Copies any selected text
Ctrl+V	Pastes clipboard at caret marker
Ctrl+D	Duplicates the current line (duplicated line is below)
Ctrl+K	Deletes (Kills) the current line (file moves up to fill gap)
Ctrl+L	Goes to a line (small dialog popup)
Ctrl+T	Swaps (Transposes) the current line with the line above

File System

Key	Action
Ctrl+S	Save a file (single-line filename prompt)
Ctrl+O	Open a file (single-line filename prompt)

Misc

Key	Action
Insert	Toggle between insert and overwrite modes (have this displayed in the same pseudo-status bar as column number)
Ctrl+X, Alt+X, Ctrl+W	Closes the editor. Prompts if you want to save any unsaved changes first (if there are any).

Here's some extended nano functionality I could co-opt into making this sane fork of nano.