7491e172ea
The eopl language is now racket-based rather than mzscheme-based. This test-suite, which was originally distributed on the book's web-site has been re-written in the new language. Changes include dropping all drscheme-init.scm and top.scm files. Remaining files were renamed to use the .rkt extension and edited to use the #lang syntax (instead of modulue). Require and provide forms were changed to reflect racket's syntax instead of mzscheme's (eg, only-in vs. only). Several occurrences of one-armed ifs were changed to use when and unless. All tests have been run successfully.
93 lines
2.2 KiB
Racket
Executable File
93 lines
2.2 KiB
Racket
Executable File
#lang eopl
|
|
|
|
;; data structures for LEXADDR language
|
|
|
|
(require "lang.rkt") ; for expression?
|
|
|
|
(provide (all-defined-out)) ; too many things to list
|
|
|
|
;;;;;;;;;;;;;;;; expressed values ;;;;;;;;;;;;;;;;
|
|
|
|
;;; an expressed value is either a number, a boolean or a procval.
|
|
|
|
(define-datatype expval expval?
|
|
(num-val
|
|
(value number?))
|
|
(bool-val
|
|
(boolean boolean?))
|
|
(proc-val
|
|
(proc proc?)))
|
|
|
|
;;; extractors:
|
|
|
|
;; expval->num : ExpVal -> Int
|
|
(define expval->num
|
|
(lambda (v)
|
|
(cases expval v
|
|
(num-val (num) num)
|
|
(else (expval-extractor-error 'num v)))))
|
|
|
|
;; expval->bool : ExpVal -> Bool
|
|
(define expval->bool
|
|
(lambda (v)
|
|
(cases expval v
|
|
(bool-val (bool) bool)
|
|
(else (expval-extractor-error 'bool v)))))
|
|
|
|
;; expval->proc : ExpVal -> Proc
|
|
(define expval->proc
|
|
(lambda (v)
|
|
(cases expval v
|
|
(proc-val (proc) proc)
|
|
(else (expval-extractor-error 'proc v)))))
|
|
|
|
(define expval-extractor-error
|
|
(lambda (variant value)
|
|
(eopl:error 'expval-extractors "Looking for a ~s, found ~s"
|
|
variant value)))
|
|
|
|
;;;;;;;;;;;;;;;; procedures ;;;;;;;;;;;;;;;;
|
|
|
|
|
|
;; proc? : SchemeVal -> Bool
|
|
;; procedure : Exp * Nameless-env -> Proc
|
|
(define-datatype proc proc?
|
|
(procedure
|
|
;; in LEXADDR, bound variables are replaced by %nameless-vars, so
|
|
;; there is no need to declare bound variables.
|
|
;; (bvar symbol?)
|
|
(body expression?)
|
|
;; and the closure contains a nameless environment
|
|
(env nameless-environment?)))
|
|
|
|
;;;;;;;;;;;;;;;; environment constructors and observers ;;;;;;;;;;;;;;;;
|
|
|
|
;; nameless-environment? : SchemeVal -> Bool
|
|
;; Page: 99
|
|
(define nameless-environment?
|
|
(lambda (x)
|
|
((list-of expval?) x)))
|
|
|
|
;; empty-nameless-env : () -> Nameless-env
|
|
;; Page: 99
|
|
(define empty-nameless-env
|
|
(lambda ()
|
|
'()))
|
|
|
|
;; empty-nameless-env? : Nameless-env -> Bool
|
|
(define empty-nameless-env?
|
|
(lambda (x)
|
|
(null? x)))
|
|
|
|
;; extend-nameless-env : ExpVal * Nameless-env -> Nameless-env
|
|
;; Page: 99
|
|
(define extend-nameless-env
|
|
(lambda (val nameless-env)
|
|
(cons val nameless-env)))
|
|
|
|
;; apply-nameless-env : Nameless-env * Lexaddr -> ExpVal
|
|
;; Page: 99
|
|
(define apply-nameless-env
|
|
(lambda (nameless-env n)
|
|
(list-ref nameless-env n)))
|