Method replace

src/main/java/wycc/lang/Syntactic.java:201–201

Replace all references to a given syntactic item with references to another syntactic item. Observe that all reachable items are traversed, except for those within the item being replaced. The original item remains until the next garbage collection phase. @param from @param to

(T from, T to)

		 * @param to
		 */
		public <T extends Item> void replace(T from, T to);

		/**
		 * Trigger garbage collection for this heap. This may result in the indices of