#:printer filed in language specification.

[Justin Veilleux]

Hello, everyone.

To familiarize myself with guile's compiler tower, I implemented a 
lambda calculus interpreter using guile.

It works relatively well. However, I also wanted it to print a human 
readable version of the procedures created. (It is hard to tell whether 
#<procedure 1e39a38 (s)> is a correct church encoding of the number 3) 
With a lot of fiddling, I managed to write a function that turns a 
procedure into an S-expression.

However, when I tell guile to use it as a pretty printer using the 
#:printer keyword, the repl doesn't actually use it. What can I do to 
fix this ?