33 lines
1.1 KiB
Racket
33 lines
1.1 KiB
Racket
#lang typed/racket/base
|
|
|
|
(provide (all-defined-out))
|
|
|
|
;;;;;;;;;;;;;;
|
|
|
|
;; Lexical environments
|
|
|
|
;; A toplevel prefix contains a list of toplevel variables.
|
|
(define-struct: Prefix ([names : (Listof Symbol)])
|
|
#:transparent)
|
|
|
|
|
|
|
|
|
|
|
|
(define-type CompileTimeEnvironmentEntry (U False ;; placeholder for temporary space
|
|
Symbol ;; lexically bound local identiifer
|
|
Prefix ;; a prefix
|
|
))
|
|
|
|
;; A compile-time environment is a (listof (listof symbol)).
|
|
;; A lexical address is either a 2-tuple (depth pos), or 'not-found.
|
|
(define-type CompileTimeEnvironment (Listof CompileTimeEnvironmentEntry))
|
|
|
|
;; A lexical address is a reference to an value in the environment stack.
|
|
(define-type LexicalAddress (U LocalAddress PrefixAddress))
|
|
(define-struct: LocalAddress ([depth : Natural])
|
|
#:transparent)
|
|
(define-struct: PrefixAddress ([depth : Natural]
|
|
[pos : Natural]
|
|
[name : Symbol])
|
|
#:transparent) |