In-place mutation in a functional language dates back as far as 1994, when it was introduced for Clean in the paper 'Guaranteeing safe destructive updates throu

In-place mutation in a functional language dates back as far as 1994, when it was introduced for Clean in the paper 'Guaranteeing safe destructive updates through a type system with uniqueness information for graphs'[1]. The FP2 paper references a subsequent 1995 paper from the same authors, 'Uniqueness Type Inference'[2]. More publications about Clean here: https://clean.cs.ru.nl/Publications https://clean.cs.ru.nl/Publications [1] http://www.mbsd.cs.ru.nl/publications/papers/1994/smes94-guaranteeing.pdf http://www.mbsd.cs.ru.nl/publications/papers/1994/smes94-gua... [2] http://www.mbsd.cs.ru.nl/publications/papers/1995/bare95-unitypeinference.ps.gz http://www.mbsd.cs.ru.nl/publications/papers/1995/bare95-uni...