Implement per-word (B/E/W/GE) movement in vim mode

Author: marijnh

keymap/vim.js

@@ -11,9 +11,41 @@
     for (var prop in o) if (o.hasOwnProperty(prop)) f(prop, o[prop]);
   }
 
+  var word = [/\w/, /[^\w\s]/], bigWord = [/\S/];
+  function findWord(line, pos, dir, regexps) {
+    var stop = 0, next = -1;
+    if (dir > 0) { stop = line.length; next = 0; }
+    var start = stop, end = stop;
+    // Find bounds of next one.
+    outer: for (; pos != stop; pos += dir) {
+      for (var i = 0; i < regexps.length; ++i) {
+        if (regexps[i].test(line.charAt(pos + next))) {
+          start = pos;
+          for (; pos != stop; pos += dir) {
+            if (!regexps[i].test(line.charAt(pos + next))) break;
+          }
+          end = pos;
+          break outer;
+        }
+      }
+    }
+    return {from: Math.min(start, end), to: Math.max(start, end)};
+  }
+  function moveToWord(cm, regexps, dir, where) {
+    var cur = cm.getCursor(), ch = cur.ch, line = cm.getLine(cur.line), word;
+    while (true) {
+      word = findWord(line, ch, dir, regexps);
+      ch = word[where == "end" ? "to" : "from"];
+      if (ch == cur.ch && word.from != word.to) ch = word[dir < 0 ? "from" : "to"];
+      else break;
+    }
+    cm.setCursor(cur.line, word[where == "end" ? "to" : "from"], true);
+  }
+
   var map = CodeMirror.keyMap.vim = {
     "0": function(cm) {count.length > 0 ? pushCountDigit("0")(cm) : CodeMirror.commands.goLineStart(cm);},
     "I": function(cm) {popCount(); cm.setOption("keyMap", "vim-insert");},
+    "G": function(cm) {cm.setOption("keyMap", "vim-prefix-g");},
     catchall: function(cm) {/*ignore*/}
   };
   // Add bindings for number keys
@@ -22,9 +54,21 @@
   iterObj({"H": "goColumnLeft", "L": "goColumnRight", "J": "goLineDown", "K": "goLineUp",
 		       "Left": "goColumnLeft", "Right": "goColumnRight", "Down": "goLineDown", "Up": "goLineUp",
            "Backspace": "goCharLeft", "Space": "goCharRight",
+           "B": function(cm) {moveToWord(cm, word, -1, "end");},
+           "E": function(cm) {moveToWord(cm, word, 1, "end");},
+           "W": function(cm) {moveToWord(cm, word, 1, "start");},
+           "Shift-B": function(cm) {moveToWord(cm, bigWord, -1, "end");},
+           "Shift-E": function(cm) {moveToWord(cm, bigWord, 1, "end");},
+           "Shift-W": function(cm) {moveToWord(cm, bigWord, 1, "start");},
            "U": "undo", "Ctrl-R": "redo", "Shift-4": "goLineEnd"},
           function(key, cmd) { map[key] = countTimes(cmd); });
 
+  CodeMirror.keyMap["vim-prefix-g"] = {
+    "E": countTimes(function(cm) { moveToWord(cm, word, -1, "start");}),
+    "Shift-E": countTimes(function(cm) { moveToWord(cm, bigWord, -1, "start");}),
+    auto: "vim", catchall: function(cm) {/*ignore*/}
+  };
+
   CodeMirror.keyMap["vim-insert"] = {
     "Esc": function(cm) {cm.setOption("keyMap", "vim");},
     fallthrough: ["default"]