Add a findMarks method

Closes #2200

Author: marijnh

doc/manual.html

@@ -1293,6 +1293,9 @@ <h3 id="api_marker">Text-marking methods</h3>
         to the left instead.</dd>
       </dl></dd>
 
+      <dt id="findMarks"><code><strong>doc.findMarks</strong>(from: {line, ch}, to: {line, ch}) → array&lt;TextMarker&gt;</code></dt>
+      <dd>Returns an array of all the bookmarks and marked ranges
+      found between the given positions.</dd>
       <dt id="findMarksAt"><code><strong>doc.findMarksAt</strong>(pos: {line, ch}) → array&lt;TextMarker&gt;</code></dt>
       <dd>Returns an array of all the bookmarks and marked ranges
       present at the given position.</dd>

lib/codemirror.js

@@ -5072,6 +5072,22 @@ window.CodeMirror = (function() {
       }
       return markers;
     },
+    findMarks: function(from, to) {
+      from = clipPos(this, from); to = clipPos(this, to);
+      var found = [], lineNo = from.line;
+      this.iter(from.line, to.line + 1, function(line) {
+        var spans = line.markedSpans;
+        if (spans) for (var i = 0; i < spans.length; i++) {
+          var span = spans[i];
+          if (!(lineNo == from.line && from.ch > span.to ||
+                span.from == null && lineNo != from.line||
+                lineNo == to.line && span.from > to.ch))
+            found.push(span.marker.parent || span.marker);
+        }
+        ++lineNo;
+      });
+      return found;
+    },
     getAllMarks: function() {
       var markers = [];
       this.iter(function(line) {