[gilmi]

A different thing to look at is what enforcing referential transparency in your program means.

Referential transparency means that when we bind an expression to a name (e.g. `y = f x`), the two are interchangeable, and whenever we use `y` we could just as well use `f x` and vice versa, and the meaning of the code will stay the same.

Enforcing referential transparency in a programming language means that:

- We need to have more control over effects (purity)

- We can use substitution and equational reasoning

The value of referential transparency for me is that I can trust code to not surprise me with unexpected effects, I can use substitution to understand what a piece of code is doing, and I can always refactor by converting a piece of code to a new value or function because referential transparency guarantees that they are equivalent.

Because of that I feel like I can always understand how something works because I have a simple process to figure things out that doesn't require me keeping a lot of context in my head. I never feel like something is "magic" that I cannot understand. And I can easily change code to understand it better without changing its meaning.

Referential transparency is freeing, and makes me worry less when working with code!

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The other part that is very notable about Haskell is one of its approaches to concurrency - Software Transactional Memory. Which is enabled by limiting the kind of effects we can perform in a transaction block:

https://www.oreilly.com/library/view/parallel-and-concurrent...