Problem Statement

The use of   abbreviations   (also sometimes called synonyms, nicknames, AKAs, or aliases)   can be an easy way to add flexibility when specifying or using commands, sub─commands, options, etc.

It would make a list of words easier to maintain   (as words are added, changed, and/or deleted)   if the minimum abbreviation length of that list could be automatically (programmatically) determined.

For this task, use the list (below) of the days-of-the-week names that are expressed in about a hundred languages   (note that there is a blank line in the list). Caveat:   The list (above) most surely contains errors (or, at the least, differences) of what the actual (or true) names for the days-of-the-week.

To make this Rosetta Code task page as small as possible, if processing the complete list, read the days-of-the-week from a file (that is created from the above list).

Notes concerning the above list of words

Let's start with the solution:

#lang racket

(require racket/set)

(define (abbr-length ss)
  (for*/first ((l (in-range 1 (string-length (argmax string-length ss))))
               #:when (equal? (sequence-length
                               (for/set ((s ss))
                                 (substring s 0 (min l (string-length s)))))
                              (length ss)))
    l))

(module+ main
  (define report-line
    (match-lambda
      ["" ""]
      [(and s (app string-split ss)) (format "~a ~a" (abbr-length ss) s)]))
  (for-each (compose displayln report-line) (take (file->lines "data.txt") 5)))