[pure function] confluence

[dannypsnl]

Confluence means that the order of performing various subcomputations doesn’t matter so long as they all finish: in the expression (2 + 5) * (3 + 6), it doesn’t matter which addition you do first or whether you distribute the expressions over each other; the answer is the same.

The example of confluence in lambda calculus is beta reduction, and this is the most pure function similar formal idea I can find

[dannypsnl]

純函數跟特定系統連結太深了，就算直觀上兩個好像一樣，但在不同系統裡面可能一個純一個不純啊

舉個例子，在 C 語言裡面總是能用堆疊溢位影響任意函數的操作，這樣真的還有「純函數」嗎？實際上編譯器也是直接放任不管，出包是開發者的責任

[FizzyElt]

提兩個不同情境的案例，並請讀者自己留意有這件事

[dannypsnl]

https://types.pl/@pigworker/111320767229027862