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.
176 lines
4.5 KiB
Racket
Executable File
176 lines
4.5 KiB
Racket
Executable File
#lang eopl
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(require tests/eopl/private/utils)
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;; in-S? : N -> Bool
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;; usage: (in-S? n) = #t if n is in S, #f otherwise
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;; The set S is defined in Definition 1.1.1 on page 2.
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(define in-S?
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(lambda (n)
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(if (zero? n) #t
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(if (>= (- n 3) 0) (in-S? (- n 3))
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#f))))
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(check-equal? (in-S? 0) #t)
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(check-equal? (in-S? 1) #f)
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(check-equal? (in-S? 2) #f)
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(check-equal? (in-S? 3) #t)
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(check-equal? (in-S? 4) #f)
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(check-equal? (in-S? 9) #t)
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;; list-length : List -> Int
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;; usage: (list-length l) = the length of l
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;; Page: 14
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(define list-length
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(lambda (lst)
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(if (null? lst)
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0
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(+ 1 (list-length (cdr lst))))))
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(check-equal? (list-length '(a (b c) d)) 3)
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;; nth-element : List * Int -> SchemeVal
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;; usage: (nth-element lst n) = the nth element of lst
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;; Page: 15
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(define nth-element
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(lambda (lst n)
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(if (null? lst)
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(report-list-too-short n)
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(if (zero? n)
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(car lst)
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(nth-element (cdr lst) (- n 1))))))
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(define report-list-too-short
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(lambda (n)
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(eopl:error 'nth-element
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"List too short by ~s elements.~%" (+ n 1))))
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(check-equal? (nth-element '(a b c) 1) 'b)
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(check-equal? (nth-element '(a b c) 2) 'c)
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(check-error (nth-element '() 5)
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"nth-element: List too short by 6 elements.\n")
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;; remove-first : Sym * Listof(Sym) -> Listof(Sym)
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;; Page: 18
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(define remove-first
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(lambda (s los)
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(if (null? los)
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'()
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(if (eqv? (car los) s)
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(cdr los)
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(cons (car los) (remove-first s (cdr los)))))))
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(check-equal? (remove-first 'a '(a b c)) '(b c))
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(check-equal? (remove-first 'b '(e f g)) '(e f g))
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(check-equal? (remove-first 'a4 '(c1 a4 c1 a4)) '(c1 c1 a4))
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(check-equal? (remove-first 'x '()) '())
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;; occurs-free? : Sym * Lcexp -> Bool
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;; usage:
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;; returns #t if the symbol var occurs free in exp,
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;; otherwise returns #f.
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;; Page: 19
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(define occurs-free?
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(lambda (var exp)
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(cond
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((symbol? exp) (eqv? var exp))
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((eqv? (car exp) 'lambda)
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(and
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(not (eqv? var (car (cadr exp))))
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(occurs-free? var (caddr exp))))
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(else
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(or
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(occurs-free? var (car exp))
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(occurs-free? var (cadr exp)))))))
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(check-equal? (occurs-free? 'x 'x) #t)
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(check-equal? (occurs-free? 'x 'y) #f)
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(check-equal? (occurs-free? 'x '(lambda (x) (x y))) #f)
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(check-equal? (occurs-free? 'x '(lambda (y) (x y))) #t)
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(check-equal? (occurs-free? 'x '((lambda (x) x) (x y))) #t)
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(check-equal? (occurs-free? 'x '(lambda (y) (lambda (z) (x (y z))))) #t)
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;; subst : Sym * Sym * S-list -> S-list
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;; Page: 21
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(define subst
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(lambda (new old slist)
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(if (null? slist)
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'()
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(cons
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(subst-in-s-exp new old (car slist))
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(subst new old (cdr slist))))))
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;; subst-in-s-exp : Sym * Sym * S-exp -> S-exp
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;; Page: 21
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(define subst-in-s-exp
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(lambda (new old sexp)
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(if (symbol? sexp)
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(if (eqv? sexp old) new sexp)
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(subst new old sexp))))
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(check-equal? (subst 'a 'b '((b c) (b () d)))
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'((a c) (a () d)))
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;; number-elements-from : Listof(SchemeVal) * Int ->
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;; Listof(List(Int,SchemeVal))
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;; usage: (number-elements-from '(v0 v1 v2 ...) n)
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;; = ((n v0 ) (n+1 v1) (n+2 v2) ...)
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;; Page: 23
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(define number-elements-from
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(lambda (lst n)
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(if (null? lst) '()
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(cons
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(list n (car lst))
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(number-elements-from (cdr lst) (+ n 1))))))
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(check-equal? (number-elements-from '(a b c) 5)
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'((5 a) (6 b) (7 c)))
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;; number-elements : List -> Listof(List(Int,SchemeVal))
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;; Page: 23.
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(define number-elements
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(lambda (lst)
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(number-elements-from lst 0)))
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(check-equal? (number-elements '(a b c))
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'((0 a) (1 b) (2 c)))
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;; list-sum : Listof(Int) -> Int
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;; Page: 24
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(define list-sum
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(lambda (loi)
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(if (null? loi)
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0
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(+ (car loi)
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(list-sum (cdr loi))))))
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(check-equal? (list-sum (list 1 2 3 4 5)) 15)
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;; partial-vector-sum : Vectorof(Int) * Int -> Int
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;; usage if 0 <= n < length(v), then
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;; (partial-vector-sum v n) = SUM(v_i from 0 <= i <= n)
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;; Page: 25
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(define partial-vector-sum
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(lambda (v n)
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(if (zero? n)
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(vector-ref v 0)
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(+ (vector-ref v n)
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(partial-vector-sum v (- n 1))))))
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;; vector-sum : Vectorof(Int) -> Int
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;; usage (vector-sum v) = SUM(v_i from 0 <= i <= length(v)-1)
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;; Page: 25
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(define vector-sum
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(lambda (v)
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(let ((n (vector-length v)))
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(if (zero? n)
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0
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(partial-vector-sum v (- n 1))))))
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(check-equal? (vector-sum (vector 1 2 3 4 5)) 15)
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