Record Metadata: Asking Questions About Records

LFE inherits Erlang’s record-info mechanism for querying record metadata:

lfe> (record-info 'fields 'person)
(name age phone)

lfe> (record-info 'size 'person)
4  ; three fields plus the tag atom

Note that these must be literal atoms—you can’t use variables. The compiler needs to know at compile time what you’re asking about, because records don’t exist at runtime. It’s a bit like asking someone to describe a dream: the description exists, but the dream itself is merely a neural firing pattern that’s long since dissipated.