[malisper]

> The rewrite also could have simpler code in some cases

The Rust code is a literal translation of the Postgres code which returns the value at the end instead of an early return.

> I see a lot of MemoryContext

MemoryContext in C is used for multiple reasons: 1) performance 2) keeping track of how much memory has been allocated and where and 3) preventing memory leaks.

Reasons 1 and 2 are still relevant for Rust. The challenge is in C memory contexts are stored in a global variable. Global variables don't work well with the rust borrow checker so I opted for passing memory contexts as function arguments instead.