This `map` operation can be replaced with a `for/list` loop.

Internal definitions are recommended instead of `let` expressions, to reduce nesting.

This `let` expression can be pulled up into a `define` expression.

Use the `#:unless` keyword instead of `unless` to reduce loop body indentation.

Use the `#:when` keyword instead of `when` to reduce loop body indentation.

This variable is returned immediately and can be inlined.

This `hash-map` expression is equivalent to the `hash-keys` function.

This `begin` form can be flattened into the surrounding definition context.

`cond` with internal definitions is preferred over `if` with `let`, to reduce nesting

This expression can be replaced with a simpler, equivalent `hash-ref!` expression.

This `match` expression can be simplified using `match-define`.

Using `when` and `unless` is simpler than a conditional with an always-throwing branch.