* `killring.js` - killring for kill & yank handling in readline

* Readline has not been tested with non-ascii.

***josh*** is built from 5 components and can be used in part or in full.

`readline.js` has no dependencies on any outside libraries, although it requires either `history.js` and `killring.js` or objects implementing the same calls.

In the below `C-x` refers to the `Ctrl-x` keystroke, while `M-x` refers to the `Meta-x` which is mapped to `Alt`, `⌘` and `Left Windows`.

<dl>

<dt><em>Movement</em></dt>

<dt><code>C-b</code> or <code>Left Arrow</code></dt>

<dd>Move back one character</dd>

<dt><code>M-b</code> or <code>Right Arrow</code></dt>

<dd>Move back one word</dd>

<dt><code>C-f</code></dt>

<dd>Move forward one character</dd>

<dt><code>M-f</code></dt>

<dd>Move forward one word</dd>

<dt><code>C-a</code> or <code>Home</code></dt>

<dd>Move to the beginning of the line</dd>

<dt><code>C-e</code> or <code>End</code></dt>

<dd>Move to the end of the line</dd>

<br/>

<dt><em>Edit/Kill</em></dt>

<dt><code>Backspace</code></dt>

<dd>Delete one character back</dd>

<dt><code>C-d</code> or <code>Delete</code></dt>

<dd>Delete character under cursor</dd>

<dt><code>C-k</code></dt>

<dd><em>Kill</em> (i.e. put in kill ring) text to the end of the line</dd>

<dt><code>M-Backspace</code></dt>

<dd><em>Kill</em> one word back</dd>

<dt><code>M-d</code></dt>

<dd><em>Kill</em> word under cursor</dd>

<dt><code>C-y</code></dt>

<dd><em>Yank</em> (i.e. pull from kill ring) the most recently <em>killed</em> text</dd>

<dt><code>M-y</code></dt>

<dd>Rotate to the next item in killring and yank it. Must be preceded by <em>yank</em></dd>

<br/>

<dt><em>History</em></dt>

<dt><code>C-r</code></dt>

<dd>Reverse search through history</dd>

<dt><code>C-p</code> or <code>Up Arrow</code></dt>

<dd>Previous entry in history</dd>

<dt><code>C-n</code> or <code>Down Arrow</code></dt>

<dd>Next entry in history</dd>

<dt><code>Page Up</code></dt>

<dd>Top of history</dd>

<dt><code>Page Down</code></dt>

<dd>Bottom of history</dd>

<br/>

<dt><em>Misc</em></dt>

<dt><code>C-l</code></dt>

<dd>refresh line (clear screen in shell)</dd>

<dt><code>Tab</code></dt>

<dd>Invoke completion handler for text under cursor</dd>

<dt><code>C-c</code> or <code>Esc</code></dt>

<dd>Deactivate Readline (closes the shell)</dd>

<dt><code>~</code></dt>

<dd>Activate Readline (opens the shell)</dd>

</dl>

`killing.js` implements the kill and yank behavior as well as state tracking, i.e. multiple consecutive kills are combined as a single kill and killring rotation tracks the previous yank, so that the `readline.js` can remove the previous yank and replace it with the rotated text.

<script src="js/killring.js"></script>

width: 97.0%;

left: 0;

overflow:scroll;

overflow-x:hidden;

overflow-y: scroll;

var killring = new Josh.KillRing();

var readline = new Josh.ReadLine({history: history, killring: killring, console: _console });

var shell = Josh.Shell({readline: readline, history: history, console: _console});

var killringItemTemplate = _.template("<div><%- i %>&nbsp;<%- cmd %></div>");

shell.setCommandHandler("killring", {

exec: function(cmd, args, callback) {

if(args[0] == "-c") {

killring.clear();

callback();

return;

}

var content = $('<div></div>');

_.each(killring.items(), function(cmd, i) {

content.append(killringItemTemplate({cmd: cmd, i: i}));

});

callback(content);

}

});

Josh.Instance = {

PathHandler: pathhandler,

KillRing: killring

var Josh = Josh || {};

(function(root) {

Josh.KillRing = function(config) {

config = config || {};

var _console = Josh.Debug && root.console ? root.console : {log: function() {

}};

var _ring = config.ring || [];

var _cursor = config.cursor || 0;

var _uncommitted = false;

var _yanking = false;

if(_ring.length == 0) {

_cursor = -1;

} else if(_cursor >= _ring.length) {

_cursor = _ring.length - 1;

}

var self = {

isinkill: function() {

return _uncommitted;

},

lastyanklength: function() {

if(!_yanking) {

return 0;

}

return _ring[_cursor].length;

},

append: function(value) {

_yanking = false;

if(!value) {

return;

}

if(_ring.length == 0 || !_uncommitted) {

_ring.push('');

}

_cursor = _ring.length - 1;

_console.log("appending: " + value);

_uncommitted = true;

_ring[_cursor] += value;

},

prepend: function(value) {

_yanking = false;

if(!value) {

return;

}

if(_ring.length == 0 || !_uncommitted) {

_ring.push('');

}

_cursor = _ring.length - 1;

_console.log("prepending: " + value);

_uncommitted = true;

_ring[_cursor] = value + _ring[_cursor];

},

commit: function() {

_console.log("committing");

_yanking = false;

_uncommitted = false;

},

yank: function() {

self.commit();

if(_ring.length == 0) {

return null;

}

_yanking = true;

return _ring[_cursor];

},

rotate: function() {

if(!_yanking || _ring.length == 0) {

return null;

}

--_cursor;

if(_cursor < 0) {

_cursor = _ring.length - 1;

}

return self.yank();

},

items: function() {

return _ring.slice(0);

},

clear: function() {

_ring = [];

_cursor = -1;

_yanking = false;

_uncommited = false;

}

};

return self;

}

config = config || {};