Chris Okasaki is an associate professor of computer science at the United States Military Academy.
He authored Purely Functional Data Structures (1998), based on a doctoral dissertation of the same name.
He obtained a Ph.D. at Carnegie Mellon University in 1996 under advisers Peter Lee, Robert Harper, Daniel Sleator, and Robert Tarjan.
[2] Okasaki published his doctoral dissertation as a book in 1998.
It approaches the topic of data structures from a functional programming perspective, describing techniques for designing immutable structures that incorporate persistence.