[vineyardmike]

Your presented alternative is basically the same thing with named step outputs. I don’t see how chaining is something crazy or problematic in comparison. The only difference is chaining reduces syntactic “noise”. It’s easier to read.

One-time use variables that are consumed on the next line aren’t valuable. Chaining exists as a widely used pattern because it’s useful to not generate a ton of intermediary variables.

In fact, the typing point you bring up is actually less clear. In the iterator chain, the type is “iterator”, which is a standard type that can be produced from many sources as business requirements change. In your example, the types need be compared to the function parameters and methods need to be written explicitly use the same types.