NOTE: ee-lib
1. Introduction
ee-lib is an amazing library made by Michael Ballantyne, it provides a convenience local context let user can record meta information for a macro, but there have some behaviors I want to record for future development.
2. Note
2.1. Binding will disappear when add-scope on the syntax
(define-syntax-parser mydef
[(_ n:id e:expr)
(with-scope sc
(with-syntax ([new-n (add-scope #'n sc)])
#'(define new-n e)))])
(mydef a 1)
a
Error:
a: unbound identifier in: a
You can print #'new-n to check this fact. Hence, if you want to
generate an identifier for a definition, ensure that identifier isn't
get from add-scope.
2.2. You cannot bind identifier out of scope
(define-syntax-parser mydef
[(_ n:id e:expr)
(bind! #'n #'1)
(with-scope sc
#'(define n e))])
Error:
bind!: cannot bind outside of dynamic extent of with-scope
This makes sense, because you might not like to affect others context, this example tells the purpose of the library.
3. Example
In the end, here is a small normal usage of the library.
(define-syntax-parser mydef
[(_ n:id e:expr)
(with-scope sc
(bind! #'n #'(* 10 e))
(with-syntax ([e (lookup #'n)])
#'(define n e)))])
(mydef a 1)
a
Result: 10