add readline support for meta-f and meta-b

lib/readline.js

@@ -15,7 +15,6 @@ var EventEmitter = require('events').EventEmitter;
 var stdio = process.binding('stdio');
 
 
-
 exports.createInterface = function (output, completer) {
   return new Interface(output, completer);
 };
@@ -347,10 +346,37 @@ Interface.prototype._ttyWrite = function (b) {
       return;
 
     case 27:    /* escape sequence */
+      var next_word, next_non_word, previous_word, previous_non_word;
       if (b[1] === 98 && this.cursor > 0) { // meta-b - backward word
-
+	previous_word = this.line.slice(0, this.cursor)
+			  .split('').reverse().join('')
+			  .search(/\w/);
+	if (previous_word !== -1) {
+	  previous_non_word = this.line.slice(0, this.cursor - previous_word)
+				.split('').reverse().join('')
+				.search(/\W/);
+	  if (previous_non_word !== -1) {
+	    this.cursor -= previous_word + previous_non_word;
+	    this._refreshLine();
+	    break;
+	  }
+	}
+	this.cursor = 0;
+	this._refreshLine();
       } else if (b[1] === 102 && this.cursor < this.line.length) { // meta-f - forward word
-
+	next_word = this.line.slice(this.cursor, this.line.length)
+		      .search(/\w/);
+	if (next_word !== -1) {
+	  next_non_word = this.line.slice(this.cursor + next_word, this.line.length)
+			    .search(/\W/);
+	  if (next_non_word !== -1) {
+	    this.cursor += next_word + next_non_word;
+	    this._refreshLine();
+	    break;
+	  }
+	}
+	this.cursor = this.line.length;
+	this._refreshLine();
       } else if (b[1] === 91 && b[2] === 68) { // left arrow
         if (this.cursor > 0) {
           this.cursor--;

test/simple/test-readline.js

@@ -5,7 +5,9 @@ var readline = require("readline");
 var key = {
   xterm: {
     home: [27, 91, 72],
-    end: [27, 91, 70]
+    end: [27, 91, 70],
+    metab: [27, 98],
+    metaf: [27, 102]
   },
   gnome: {
     home: [27, 79, 72],
@@ -17,15 +19,21 @@ var key = {
   }
 };
 
-var fakestream = {
-  fd: 1,
-  write: function(bytes) {
-  }
+var readlineFakeStream = function() {
+  var written_bytes = [];
+  var rl = readline.createInterface({
+    fd: 1,
+    write: function(b) {
+      written_bytes.push(b);
+    }}, function (text) {
+      return [[], ""];
+    });
+  rl.written_bytes = written_bytes;
+  return rl;
 };
 
-var rl = readline.createInterface(fakestream, function (text) {
-  return [[], ""];
-});
+var rl = readlineFakeStream();
+var written_bytes_length, refreshed;
 
 rl.write('foo');
 assert.equal(3, rl.cursor);
@@ -41,3 +49,35 @@ rl.write(key.gnome.home);
 assert.equal(0, rl.cursor);
 rl.write(key.gnome.end);
 assert.equal(3, rl.cursor);
+
+rl = readlineFakeStream();
+rl.write('foo bar.hop/zoo');
+rl.write(key.xterm.home);
+written_bytes_length = rl.written_bytes.length;
+rl.write(key.xterm.metaf);
+assert.equal(3, rl.cursor);
+refreshed = written_bytes_length !== rl.written_bytes.length;
+assert.equal(true,  refreshed);
+rl.write(key.xterm.metaf);
+assert.equal(7, rl.cursor);
+rl.write(key.xterm.metaf);
+assert.equal(11, rl.cursor);
+written_bytes_length = rl.written_bytes.length;
+rl.write(key.xterm.metaf);
+assert.equal(15, rl.cursor);
+refreshed = written_bytes_length !== rl.written_bytes.length;
+assert.equal(true,  refreshed);
+written_bytes_length = rl.written_bytes.length;
+rl.write(key.xterm.metab);
+assert.equal(12, rl.cursor);
+refreshed = written_bytes_length !== rl.written_bytes.length;
+assert.equal(true,  refreshed);
+rl.write(key.xterm.metab);
+assert.equal(8, rl.cursor);
+rl.write(key.xterm.metab);
+assert.equal(4, rl.cursor);
+written_bytes_length = rl.written_bytes.length;
+rl.write(key.xterm.metab);
+assert.equal(0, rl.cursor);
+refreshed = written_bytes_length !== rl.written_bytes.length;
+assert.equal(true,  refreshed);