The (aux commons) module

(define (test/map-values _)
  (⊦= '(1 2 3) (map (λ (i) (values (add1 i) i)) '(0 1 2)))
  (⊦= '(1 2 3)
      ((map/call-with-values (λ (i) (values (add1 i) i)) (λ (more less) more))
       '(0 1 2)))
  (⊦= '((1 1) (3 3))
      ((map/values (λ (p) (values (add1 (car p)) (cadr p)))) '((0 1) (2 3)))))

((eta 0.0) (memory #(6291456 2028552 1048576)) (stdout "") (stderr ""))

(define (test/tuple-pred _)
  (⊦= #t ((tuple/pred? <) '(1 2) '(2 3) '(3 4)))
  (⊦= #f ((tuple/pred? <) '(1 5) '(2 3) '(3 4)))
  (⊦= #f ((tuple/pred? <) '(1 5) '(2) '(3 4)))
  (⊦= #t ((tuple/pred? =) '() '()))
  (⊦= #f ((tuple/pred? =) '() '(1))))

((eta 0.0) (memory #(6291456 2029616 1048576)) (stdout "") (stderr ""))

(define (test/remove-duplicates/last _)
  (⊦= '(a b c d e) (remove-duplicates/last (reverse '(a b c d e))))
  (⊦= '(e c d a b) (remove-duplicates/last '(a b a a c d c e e)))
  (⊦= '(a b c d e) (remove-duplicates '(a b a a c d c e e))))

((eta 0.0) (memory #(6291456 2030752 1048576)) (stdout "") (stderr ""))

(define (test/identity*-collect-values _)
  (⊦= '(hello world) (call-with-values (τ (values 'hello 'world)) identity*))
  (⊦= 'hello (identity* 'hello))
  (⊦= '() (identity*))
  (⊦= '(1 2) (collect-values (τ (values 1 2))))
  (⊦= 1 (collect-values (τ (values 1)))))

((eta 0.0) (memory #(6291456 2032000 1048576)) (stdout "") (stderr ""))

(define (test/symbol∼subscripts _)
  (⊦= 'g₁₂₃ (symbol∼subscripts 'g123))
  (⊦= 'x₀₉ (symbol∼subscripts 'x09))
  (⊦= 'hello (symbol∼subscripts 'hello))
  (⊦= 'α₁ (symbol∼subscripts 'α1))
  (⊦= "₇" (hash-table-ref subscripts #\7)))

((eta 0.0) (memory #(6291456 2033152 1048576)) (stdout "") (stderr ""))

(define (test/rtc _)
  (let1 (→ (λ (n) (if (< n 5) (add1 n) n)))
        (⊦= '(0 1 2 3 4 5) ((rtc →) 0))
        (⊦= '(5) ((rtc →) 5))))

((eta 0.0) (memory #(6291456 2034552 1048576)) (stdout "") (stderr ""))

(define (test/group _)
  (⊦= '((#f 5 3 1) (#t 4 2))
      (sort/lex<=?
        ((group even? (λ (p) (cons (car p) (cdr p)))) '(1 2 3 4 5)))))

((eta 0.0) (memory #(6291456 2035856 1048576)) (stdout "") (stderr ""))

(define (test/foldl1 _)
  (⊦= '() ((foldl1 +) '()))
  (⊦= 10 ((foldl1 +) '(1 2 3 4)))
  (⊦= 20 ((foldl1 + #:H₀ (λ (x) (* 11 x))) '(1 2 3 4)))
  (⊦= 8 ((foldl1/lshift + #:H₀ (λ (x) (values x cddr))) '(1 2 3 4)))
  (⊦= 10 ((foldl1/lshift +) '(1 2 3 4)))
  (⊦= '((1 . 2) . 3) ((foldl1/lshift cons) '(1 2 3))))

((eta 0.0) (memory #(6291456 2036544 1048576)) (stdout "") (stderr ""))

(define (test/within? _)
  (⊨ ((within? 1 3) 1))
  (⊨ ((within? 1 3) 2))
  (⊨ ((within? 1 3) 3))
  (⊭ ((within? 1 3) 4))
  (⊭ ((within? 1 3) 0)))

((eta 0.0) (memory #(6291456 2037680 1048576)) (stdout "") (stderr ""))

(define (test/map/tree _)
  (⊦= '(2 (3 4) ((5)) 6) ((map/tree add1) '(1 (2 3) ((4)) 5)))
  (⊦= '((2) () 3 (())) ((map/tree add1) '((1) () 2 (()))))
  (⊦= '(() (1 1)) ((map/tree (λ (x) (list x x))) '(() 1))))

((eta 0.0) (memory #(6291456 2038864 1048576)) (stdout "") (stderr ""))

(define (test/map/with-index _)
  (⊦= '((10 a) (11 b) (12 c))
      ((map/with-index (λ (i) (λ (x) (list i x))) 10) '(a b c))))

((eta 0.0) (memory #(6291456 2040264 1048576)) (stdout "") (stderr ""))

(define (test/accumulator _)
  (let1 (A (accumulator + 0)) (⊦= 1 (A 1)) (⊦= 3 (A 2)) (⊦= 6 (A 3)))
  (let1 (A (accumulator cons '())) (A 'a) (⊦= '(b a) (A 'b))))

((eta 0.0) (memory #(6291456 2041624 1048576)) (stdout "") (stderr ""))

(define (test/curried-helpers _)
  (⊦= '(2 3) ((fmap add1) '(1 2)))
  (⊦= 6 ((fapply +) '(1 2 3)))
  (⊦= '(2 4) ((ffilter even?) '(1 2 3 4)))
  (⊦= '((c . 1) (a . 2) (b . 3)) ((fsort cdr <) '((a . 2) (b . 3) (c . 1))))
  (⊦= 'b ((flist-ref '(a b c)) 1))
  (⊦= 'c ((fvector-ref #(a b c)) 2))
  (⊨ ((equals-to? '(a)) '(a)))
  (⊨ ((=to? '(a)) '(a)))
  (⊭ ((=to? (list 'a) #:same? eq?) (list 'a)))
  (⊦= 'num (cond/λ 3 (symbol? (K 'sym)) (number? (K 'num)) (else identity)))
  (⊦= "s" (cond/λ "s" (symbol? (K 'sym)) (number? (K 'num)) (else identity))))

((eta 0.0) (memory #(6291456 2042312 1048576)) (stdout "") (stderr ""))

(define (test/cond/λ/single-evaluation _)
  (define c 0)
  (define (v) (set! c (add1 c)) 5)
  (⊦= 6
      (cond/λ
        (v)
        (symbol? identity)
        (string? identity)
        (number? add1)
        (else identity)))
  (⊦= 1 c)
  (⊦= 5 (cond/λ (v) (symbol? identity) (else identity)))
  (⊦= 2 c))

((eta 0.0) (memory #(6291456 2043752 1048576)) (stdout "") (stderr ""))

(define (test/numeric-and-strings _)
  (⊦= 3 (sub2 5))
  (⊨ (≠ 'a 'b))
  (⊭ (≠ '(a) '(a)))
  (⊦= 1/4 (⁻¹ 4))
  (⊦= 16 (² 4))
  (⊦= '|42| (number->symbol 42))
  (⊦= "(1 a)" (to-string '(1 "a")))
  (call+stdout
    (τ (display "hello") 'result)
    (λ (r s) (⊦= 'result r) (⊦= "hello" s))))

((eta 0.0) (memory #(6291456 2044712 1048576)) (stdout "") (stderr ""))