Kata

This kata is the first of a sequence of four about "Squared Strings".

You are given a string of n lines, each substring being n characters long: For example:

s = "abcd\nefgh\nijkl\nmnop"

We will study some transformations of this square of strings.

• Vertical mirror: vert_mirror (or vertMirror or vert-mirror)

  vert_mirror(s) => "dcba\nhgfe\nlkji\nponm"
  

• Horizontal mirror: hor_mirror (or horMirror or hor-mirror)

   hor_mirror(s) => "mnop\nijkl\nefgh\nabcd"
  

or printed:

vertical mirror   |horizontal mirror   
abcd --> dcba     |abcd --> mnop 
efgh     hgfe     |efgh     ijkl 
ijkl     lkji     |ijkl     efgh 
mnop     ponm     |mnop     abcd 

Task:

• Write these two functions

and

• high-order function oper(fct, s) where

• fct is the function of one variable f to apply to the string s (fct will be one of vertMirror, horMirror)

Examples:

s = "abcd\nefgh\nijkl\nmnop"
oper(vert_mirror, s) => "dcba\nhgfe\nlkji\nponm"
oper(hor_mirror, s) => "mnop\nijkl\nefgh\nabcd"

Note:

The form of the parameter fct in oper changes according to the language. You can see each form according to the language in "Sample Tests".

Bash Note:

The input strings are separated by , instead of \n. The output strings should be separated by \r instead of \n. See "Sample Tests".