Type Systems in Computer programs

https://en.wikipedia.org/wiki/Type_system has good survey of the landscape. What I was looking for was duck typing (as happens in Golang)

An O(ND) Difference Algorithm and Its Variations

https://neil.fraser.name/writing/diff/myers.pdf  which is considered the best general purpose diff algorithm.  See this: https://github.com/google/diff-match-patch