txt: ## dist_zef-lizmat-P5lc.md
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  # NAME
  
  Raku port of Perl's lc() / uc() built-ins
  
  # SYNOPSIS
  
  ```
  use P5lc;
  
  say lc "FOOBAR"; # foobar
  with "ZIPPO" {
      say lc();  # zippo, may need to use parens to avoid compilation error
  }
  
  say uc "foobar"; # FOOBAR
  with "zippo" {
      say uc();  # ZIPPO, may need to use parens to avoid compilation error
  }
  
  ```
  
  # DESCRIPTION
  
  This module tries to mimic the behaviour of Perl's `lc` / `uc` built-ins as closely as possible in the Raku Programming Language.
  
  # ORIGINAL PERL 5 DOCUMENTATION
  
  ```
  lc EXPR
  lc      Returns a lowercased version of EXPR. This is the internal
          function implementing the "\L" escape in double-quoted strings.
  
          If EXPR is omitted, uses $_.
  
          What gets returned depends on several factors:
  
          If "use bytes" is in effect:
              The results follow ASCII rules. Only the characters "A-Z"
              change, to "a-z" respectively.
  
          Otherwise, if "use locale" (but not "use locale
          ':not_characters'") is in effect:
              Respects current LC_CTYPE locale for code points < 256; and
              uses Unicode rules for the remaining code points (this last
              can only happen if the UTF8 flag is also set). See perllocale.
  
              Starting in v5.20, Perl wil use full Unicode rules if the
              locale is UTF-8. Otherwise, there is a deficiency in this
              scheme, which is that case changes that cross the 255/256
              boundary are not well-defined. For example, the lower case of
              LATIN CAPITAL LETTER SHARP S (U+1E9E) in Unicode rules is
              U+00DF (on ASCII platforms). But under "use locale" (prior to
              v5.20 or not a UTF-8 locale), the lower case of U+1E9E is
              itself, because 0xDF may not be LATIN SMALL LETTER SHARP S in
              the current locale, and Perl has no way of knowing if that
              character even exists in the locale, much less what code point
              it is. Perl returns the input character unchanged, for all
              instances (and there aren't many) where the 255/256 boundary
              would otherwise be crossed.
  
          Otherwise, If EXPR has the UTF8 flag set:
              Unicode rules are used for the case change.
  
          Otherwise, if "use feature 'unicode_strings'" or "use locale
          ':not_characters'" is in effect:
              Unicode rules are used for the case change.
  
          Otherwise:
              ASCII rules are used for the case change. The lowercase of any
              character outside the ASCII range is the character itself.
  
  uc EXPR
  uc      Returns an uppercased version of EXPR. This is the internal
          function implementing the "\U" escape in double-quoted strings. It
          does not attempt to do titlecase mapping on initial letters. See
          "ucfirst" for that.
  
          If EXPR is omitted, uses $_.
  
          This function behaves the same way under various pragma, such as
          in a locale, as "lc" does.
  
  ```
  
  # PORTING CAVEATS
  
  In future language versions of Raku, it will become impossible to access the `$_` variable of the caller's scope, because it will not have been marked as a dynamic variable. So please consider changing:
  
  ```
  lc;
  
  ```
  
  to either:
  
  ```
  lc($_);
  
  ```
  
  or, using the subroutine as a method syntax, with the prefix `.` shortcut to use that scope's `$_` as the invocant:
  
  ```
  .&lc;
  
  ```
  
  # AUTHOR
  
  Elizabeth Mattijsen [liz@raku.rocks](mailto:liz@raku.rocks)
  
  If you like this module, or what I’m doing more generally, committing to a [small sponsorship](https://github.com/sponsors/lizmat/) would mean a great deal to me!
  
  Source can be located at: <https://github.com/lizmat/P5lc> . Comments and Pull Requests are welcome.
  
  # COPYRIGHT AND LICENSE
  
  Copyright 2018, 2019, 2020, 2021, 2023 Elizabeth Mattijsen
  
  Re-imagined from Perl as part of the CPAN Butterfly Plan.
  
  This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.
  