- @Abhijith LFE has in no way died, just paused the last month. There is now a wiki (in github) to help people get started and a google group for discussions.

- LFE records look the way they do as they are defined to be compatible with vanilla erlang records. Tough I know, but not much to do about it. A goal of LFE is to be compatible with vanilla erlang and the OTP libraries.

- @Laqrix That is basically compatible with LFE records, though I based naming more on CL than scheme. This happened at the same time LFE went lisp-2 and adopted a more CL style. Defrecord also defines a macro to be used when matching, in the case of dog it would be match-dog and can be used like

(match-dog name “fido” size fido-size)

which match dogs called “fido” and return the dogs size in fido-size. All unmentioned fields will match anything of course.

- @Yariv You should be careful using the tuple structure like that, if parameterized module ever get adopted it might not work anymore. :-)

(define-erlang-record dog name parent)

define-erlang-record emits a new macro ‘dog’ which provides syntax that
starts with the type name.

( make [field value] …)
( copy source [field value] …)
( instance)

For creation, fields are named and required. Generally, I don’t like
optional fields.

(define lola
(dog make [name "Lola"] [parent #f]))
(define rocky
(dog make [name "Rocky"] [parent #f]))

lola => #(dog “Lola” #f)
rocky => #(dog “Rocky” #f)

For functional updating provide copy. Any unspecified fields come from
the source record:

(define new-lola
(dog copy lola [parent rocky]))

new-lola => #(dog “Lola” #(dog “Rocky” #f))

Accessors can be used like this:

(dog name lola)

The macro can generate syntax errors for duplicate, missing, and
unknown fields. The macro can allow the fields to occur in any order.

If each accessor performs a type check, then with pattern matcher
support, you can do a single type check and extract multiple fields.

A possible matcher syntax might be:

(match x
[`(dog [name ,name] [parent ,top-dog])
;; name and top-dog are now bound in this scope
…]
…)

Food for thought.

@Abhijith I think Robert Virding is still working on it.

Dog = #dog{name = “Lolo”, parent = #dog{name = “Max”}},

not

Dog = #Dog{name = “Lolo”, parent = #dog{name = “Max”}},

?