From f6d333ef67fa2c9c199d4c401322fc31d90867da Mon Sep 17 00:00:00 2001 From: bd Date: Sat, 18 May 2024 19:12:47 -0600 Subject: Adapt palindrome into a ttd approach --- palindrome/palindrome.scm | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100755 palindrome/palindrome.scm (limited to 'palindrome/palindrome.scm') diff --git a/palindrome/palindrome.scm b/palindrome/palindrome.scm new file mode 100755 index 0000000..276e628 --- /dev/null +++ b/palindrome/palindrome.scm @@ -0,0 +1,21 @@ +(define-module (palindrome)) + + +(define-public (pp str) + "Pretty-printer wrapper for +palindrome?" + (format #f "String ~a is ~aa palindrome!\n" + str + (if (palindrome? str) + "" "not "))) + +(define-public (palindrome? str) + "Returns #t if STR is a palindrome, false +otherwise. Ignores casing and non-alphabetic +characters." + (let ((clean (cleanup str))) + (equal? clean (string-reverse clean)))) + +(define (cleanup str) + (string-downcase (string-filter + char-set:letter str))) -- cgit v1.2.3