The Doubly-Linked List Appears to Have Been Patented
I saw a tweet today that said “The doubly-linked list, a structure I studied thirty years ago, has recently been patented .” After giggling at the absurdity of the idea, I went and at a patent dated 4/11/06 that appears to be for the doubly-linked list. The prior art was extremely thin, only went back to 1995, and didn’t mention that entire computer languages have been created around the list as a core data structure. One of my first Pascal programming exercises in high school (in 1981 – on an Apple II using USDC Pascal) was to write a series of operations on lists, including both linked and doubly-linked lists (I always thought it was funny they were called “doubly-linked” instead of “double-linked” lists.) Anyone who ever graduated from MIT and took 6.001 learned to love all varieties of the linked list, including the doubly-linked one. That was 1984 for me by the way. ...