Core: Allow cloning of circular structures. (#1345)

PrismJS · Mar 13, 2018 · f90d555 · f90d555
1 parent efdccbf
commit f90d555
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Showing 3 changed files with 37 additions and 7 deletions.
diff --git a/components/prism-core.js b/components/prism-core.js
@@ -44,23 +44,38 @@ var _ = _self.Prism = {
 		},
 
 		// Deep clone a language definition (e.g. to extend it)
-		clone: function (o) {
+		clone: function (o, visited) {
 			var type = _.util.type(o);
+			visited = visited || {};
 
 			switch (type) {
 				case 'Object':
+					if (visited[_.util.objId(o)]) {
+						return visited[_.util.objId(o)];
+					}
 					var clone = {};
+					visited[_.util.objId(o)] = clone;
 
 					for (var key in o) {
 						if (o.hasOwnProperty(key)) {
-							clone[key] = _.util.clone(o[key]);
+							clone[key] = _.util.clone(o[key], visited);
 						}
 					}
 
 					return clone;
 
 				case 'Array':
-					return o.map(function(v) { return _.util.clone(v); });
+					if (visited[_.util.objId(o)]) {
+						return visited[_.util.objId(o)];
+					}
+					var clone = [];
+					visited[_.util.objId(o)] = clone;
+
+					o.forEach(function (v, i) {
+						clone[i] = _.util.clone(v, visited);
+					});
+
+					return clone;
 			}
 
 			return o;

diff --git a/components/prism-core.min.js b/components/prism-core.min.js
diff --git a/prism.js b/prism.js
@@ -49,23 +49,38 @@ var _ = _self.Prism = {
 		},
 
 		// Deep clone a language definition (e.g. to extend it)
-		clone: function (o) {
+		clone: function (o, visited) {
 			var type = _.util.type(o);
+			visited = visited || {};
 
 			switch (type) {
 				case 'Object':
+					if (visited[_.util.objId(o)]) {
+						return visited[_.util.objId(o)];
+					}
 					var clone = {};
+					visited[_.util.objId(o)] = clone;
 
 					for (var key in o) {
 						if (o.hasOwnProperty(key)) {
-							clone[key] = _.util.clone(o[key]);
+							clone[key] = _.util.clone(o[key], visited);
 						}
 					}
 
 					return clone;
 
 				case 'Array':
-					return o.map(function(v) { return _.util.clone(v); });
+					if (visited[_.util.objId(o)]) {
+						return visited[_.util.objId(o)];
+					}
+					var clone = [];
+					visited[_.util.objId(o)] = clone;
+
+					o.forEach(function (v, i) {
+						clone[i] = _.util.clone(v, visited);
+					});
+
+					return clone;
 			}
 
 			return o;