Formal comment #165 (defect)

Rename named `let'
Reported by: 	Mike Sperber
Version:	5.92

Issue

The fact that the convenient syntax for writing recursive procedures
is part of `let' is a long-standing wart in the syntax of Scheme. It
is unintuitive (it expands into `letrec', rather than a simpler form
of `let), difficult to explain to newcomers to Scheme, and
disconcerting to the casual reader.

How to fix

If the syntax needs to be integrated with one of the standard binding
forms, it should be letrec', not let'. However, it would be much
better to rename named let' to something else such as rec', `recur' or
`recursive'.

As this would break many existing Scheme programs, the report might
introduce the separate form, and, to ease the transition, keep named
`let' for now, either putting it into a separate library alongside
(r6rs mutable-pairs) or at least marking it as deprecated and likely
to disappear in a future revision of the report.


RESPONSE:

The named `let' has a more intuitive description than the comment
suggests: it can be considered a way to name the lambda implicit 
in a `let' form.  Its name refers to the fact that the bindings 
established by its <bindings> clause have `let' semantics.

It would therefore not be appropriate to base its name on `letrec', 
since a majority of the editors believe that this would create a 
misleading impression of the semantics of the <bindings>.

Given that there is a reasonable rationale for the named `let' as
a variety of `let', the reasons for renaming this feature to some 
other name such as `recur' do not seem sufficiently strong.  The 
comment will not be adopted.