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new thing - functions returning multiple values

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(values 1 2 3) at the tnd of funtion fill make funciton return 1, 2, 3
and I can either treat function as returning single value,
or use functions like multiple-value-list or multiple-value-[bind|setq]
to get secodary return values

so not quite like a tuple
This commit is contained in:
efim
2022-07-28 15:35:14 +00:00
parent 6dcca61283
commit 89673df888
3 changed files with 131 additions and 104 deletions
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109
lisp-koans/koans/hash-tables.lisp
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@@ -16,69 +16,88 @@
(define-test make-hash-table
(let ((my-hash-table (make-hash-table)))
(true-or-false? ____ (typep my-hash-table 'hash-table))
(true-or-false? ____ (hash-table-p my-hash-table))
(true-or-false? ____ (hash-table-p (make-array '(3 3 3))))
(true-or-false? t (typep my-hash-table 'hash-table))
(true-or-false? t (hash-table-p my-hash-table))
(true-or-false? nil (hash-table-p (make-array '(3 3 3))))
;; The function HASH-TABLE-COUNT returns the number of entries currently
;; contained in a hash table.
(assert-equal ____ (hash-table-count my-hash-table))))
(assert-equal 0 (hash-table-count my-hash-table))))
(define-test gethash
;; The function GETHASH can be used to access hash table values.
(let ((cube-roots (make-hash-table)))
;; We add the key-value pair 1 - "uno" to the hash table.
(setf (gethash 1 cube-roots) "uno")
(assert-equal ____ (gethash 1 cube-roots))
(assert-equal ____ (hash-table-count cube-roots))
(assert-equal "uno" (gethash 1 cube-roots))
(assert-equal 1 (hash-table-count cube-roots))
(setf (gethash 8 cube-roots) 2)
(setf (gethash -3 cube-roots) -27)
(assert-equal ____ (gethash -3 cube-roots))
(assert-equal ____ (hash-table-count cube-roots))
(assert-equal -27 (gethash -3 cube-roots))
(assert-equal 3 (hash-table-count cube-roots))
;; GETHASH returns a secondary value that is true if the key was found in
;; the hash-table and false otherwise.
(multiple-value-bind (value foundp) (gethash 8 cube-roots)
(assert-equal ____ value)
(assert-equal ____ foundp))
(assert-equal 2 value)
(assert-equal t foundp))
(multiple-value-bind (value foundp) (gethash 125 cube-roots)
(assert-equal ____ value)
(assert-equal ____ foundp))))
(assert-equal nil value)
(assert-equal nil foundp))))
(let ((my-hash (make-hash-table)))
(setf (gethash 1 my-hash) "lala-one")
(setq inner-value (gethash 1 my-hash))
(multiple-value-setq (inner-value-tuple containment-mark) (gethash 2 my-hash))
(format t "~&get hash is ~S, and variable ~S" (gethash 1 my-hash) inner-value)
(format t "~&and multi-value-setq gets ~S and ~S for key 2" inner-value-tuple containment-mark))
;; so format, gets first value
;; I guess that assigning to some variable, would also just discard second value
;; if i dont' want it?
;;
;; cool
(define-test hash-table-test
;; A hash table can be constructed with different test predicates.
;; The programmer may choose between EQ, EQL, EQUAL, and EQUALP to get the
;; best performance and expected results from the hash table.
;; The default test predicate is EQL.
(let ((eq-table (make-hash-table :test #'eq))
(eql-table (make-hash-table))
(equal-table (make-hash-table :test #'equal))
(equalp-table (make-hash-table :test #'equalp)))
;; We will define four variables whose values are strings.
(let* ((string "one")
(same-string string)
(string-copy (copy-seq string))
(string-upcased "ONE"))
;; We will insert the value of each variable into each hash table.
(dolist (thing (list string same-string string-copy string-upcased))
(dolist (hash-table (list eq-table eql-table equal-table equalp-table))
(setf (gethash thing hash-table) t))))
;; How many entries does each hash table contain?
(assert-equal ____ (hash-table-count eq-table))
(assert-equal ____ (hash-table-count eql-table))
(assert-equal ____ (hash-table-count equal-table))
(assert-equal ____ (hash-table-count equalp-table))))
;; A hash table can be constructed with different test predicates.
;; The programmer may choose between EQ, EQL, EQUAL, and EQUALP to get the
;; best performance and expected results from the hash table.
;; The default test predicate is EQL.
(let ((eq-table (make-hash-table :test #'eq))
(eql-table (make-hash-table))
(equal-table (make-hash-table :test #'equal))
(equalp-table (make-hash-table :test #'equalp)))
;; We will define four variables whose values are strings.
(let* ((string "one")
(same-string string)
(string-copy (copy-seq string))
(string-upcased "ONE"))
;; We will insert the value of each variable into each hash table.
(dolist (thing (list string same-string string-copy string-upcased))
(dolist (hash-table (list eq-table eql-table equal-table equalp-table))
(setf (gethash thing hash-table) t))))
;; How many entries does each hash table contain?
(assert-equal 3 (hash-table-count eq-table))
(assert-equal 3 (hash-table-count eql-table)) ; didn't get that on first try
;; i guess eql still not compares strings
(assert-equal 2 (hash-table-count equal-table))
(assert-equal 1 (hash-table-count equalp-table))))
(eql "hello" "hello") ; yup
(define-test hash-table-equality
;; EQUALP considers two hash tables to be equal if they have the same test and
;; if its key-value pairs are the same under that test.
(let ((hash-table-1 (make-hash-table :test #'equal))
(hash-table-2 (make-hash-table :test #'equal)))
(setf (gethash "one" hash-table-1) "yat")
(setf (gethash "one" hash-table-2) "yat")
(setf (gethash "two" hash-table-1) "yi")
(setf (gethash "two" hash-table-2) "yi")
(true-or-false? ____ (eq hash-table-1 hash-table-2))
(true-or-false? ____ (equal hash-table-1 hash-table-2))
(true-or-false? ____ (equalp hash-table-1 hash-table-2))))
;; EQUALP considers two hash tables to be equal if they have the same test and
;; if its key-value pairs are the same under that test.
(let ((hash-table-1 (make-hash-table :test #'equal))
(hash-table-2 (make-hash-table :test #'equal)))
(setf (gethash "one" hash-table-1) "yat")
(setf (gethash "one" hash-table-2) "yat")
(setf (gethash "two" hash-table-1) "yi")
(setf (gethash "two" hash-table-2) "yi")
(true-or-false? nil (eq hash-table-1 hash-table-2))
(true-or-false? nil (equal hash-table-1 hash-table-2))
(true-or-false? t (equalp hash-table-1 hash-table-2))))
;; I guess after that I want to reread difference between equal and equalp =C
;; structures EQUAL if their elements EQUAL, same with EQUALP
;; but differnt strings are not EQUAL, cool
(equal "string1" "string1")
(define-test i-will-make-it-equalp
;; Disabled on ECL due to a conformance bug.