env-printing.rkt

#lang racket/base

(require (for-syntax racket/base))


(begin-for-syntax
  (struct env (types props aliases) #:transparent)
  (define lexical-env (make-parameter (env '() '() '()))))

(define-syntax (LET stx)
  (syntax-case stx ()
    [(_ ([x y]) bodies ...)
     (and (identifier? #'x) (identifier? #'y))
     (parameterize ([lexical-env (struct-copy env (lexical-env)
                                              [aliases (cons (cons (syntax-e #'x) (syntax-e #'y))
                                                             (env-aliases (lexical-env)))])])
       (local-expand #'(let ([x y]) bodies ...) 'expression '()))]
    [(_ ([x x-val]) bodies ...)
     (identifier? #'x)
     (parameterize ([lexical-env (struct-copy env (lexical-env)
                                              [types (cons (cons (syntax-e #'x) 'Any)
                                                           (env-types (lexical-env)))])])
       (local-expand #'(let ([x x-val]) bodies ...) 'expression '()))]))





(define-syntax (trivial-print-env stx)
  (printf "env: ~a\n" (lexical-env))
  #'(void))





(LET ([x 42])
     (trivial-print-env)
     (LET ([y x])
          (trivial-print-env)
          y))





#;
(PRINT-ENV "FOO"
           (λ (thing/type-list) ;; (listof (cons any any))
             blah) ;; either #f or (-> (listof (cons any any)) string?)
           (λ (list-of-props) ;; (listof any)
             blah) ;; either #f or (-> (listof any) string?)
           (λ (aliasing) ;; (listof (cons any any))
             blah) ;; either #f or (-> (listof (cons any any)) string?)
           )