Palindrome detection

editable example

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ghul

use IO.Std.write_line

use Ghul.Collections

use Ghul.Pipes

reverse(text: string) -> string =>

text |> reduce("", (reversed, character) => "{character}{reversed}")

is_palindrome(text: string) -> bool => text =~ reverse(text)

is_inexact_palindrome(text: string) -> bool =>

text

|> filter(char.is_letter)

|> map(char.to_lower)

|> reduce("", (letters, character) => "{letters}{character}")

|> is_palindrome()

test(

maybe_palindrome: string,

palindrome_check: string -> bool

) -> string =>

if palindrome_check(maybe_palindrome) then

"\"{maybe_palindrome}\" is a palindrome"

else

"\"{maybe_palindrome}\" is not a palindrome"

fi

write_line(test("racecar", is_palindrome))

write_line(test("hello", is_palindrome))

write_line(test("rotor", is_palindrome))

write_line(test("A man, a plan, a canal: Panama", is_inexact_palindrome))

write_line(test("race car", is_inexact_palindrome))

write_line(test("hello world", is_inexact_palindrome))

"racecar" is a palindrome
"hello" is not a palindrome
"rotor" is a palindrome
"A man, a plan, a canal: Panama" is a palindrome
"race car" is a palindrome
"hello world" is not a palindrome