use Term::termios;

my sub anguish(Str:D $code) is export {
    check-matching-loop $code;
    my $saved-term;
    try {
        $saved-term = Term::termios.new(:1fd).getattr;
        given Term::termios.new(:1fd).getattr {
            .makeraw;
            .setattr(:DRAIN);
        }
    };
    LEAVE { try $saved-term.setattr(:DRAIN) }

    my @code    = $code.NFC.map(*.chr).grep:
                    * eq "\x2062"|"\x200B"|"\x2060"
                        |"\x2061"|"\x2063"|"\xFEFF"|"\x200C"|"\x200D";
    my $ꜛ       = 0;
    my $cursor  = 0;
    my $stack   = Buf[uint8].new: 0;
    loop {
        given @code[$cursor] {
            when "\x2060" { $stack.append: 0 if $stack.elems == ++$ꜛ;       }
            when "\x200B" { $ꜛ--; fail "Negative cell pointer\n" if $ꜛ < 0; }
            when "\x2061" { $stack[$ꜛ]++;               }
            when "\x2062" { $stack[$ꜛ]--;               }
            when "\x2063" { $stack[$ꜛ].chr.print;       }
            when "\xFEFF" { $stack[$ꜛ] = $*IN.getc.ord; }
            when "\x200C" {
                $cursor++; next if $stack[$ꜛ];
                loop {
                    state $level = 1;
                    $level++ if @code[$cursor] eq "\x200C";
                    $level-- if @code[$cursor] eq "\x200D";
                    last unless $level;
                    $cursor++;
                }
            }
            when "\x200D" {
                unless $stack[$ꜛ] { $cursor++; next; }
                loop {
                    state $level = 1;
                    $cursor--;
                    $level-- if @code[$cursor] eq "\x200C";
                    $level++ if @code[$cursor] eq "\x200D";
                    last unless $level;
                }
            }
        }
        last if ++$cursor > @code.elems;
    }
}

my sub check-matching-loop($code) {
    my $level = 0;
    for $code.NFC.map: *.chr {
        $level++ if $_ eq "\x200C";
        $level-- if $_ eq "\x200D";
        fail qq{Closing "\\x200D" found without matching "\\x200C"\n}
            if $level < 0;
        LAST { fail 'Unmatched \\x200C \\x200D' if $level > 0 }
    }
}



head

Acme::Anguish - Use Anguish programming language in your Raku programs


code

=begin code :lang<raku>

use Acme::Anguish;

anguish "\x2061" x 72 ~ "\x2063"; # prints "H"

=end code


I<Anguish> is a L<Brainfuck|https://en.wikipedia.org/wiki/Brainfuck>
variant that uses invisible Unicode characters instead of traditional
Brainfuck's ones.


Here's the mapping of Brainfuck operators to *Anguish*:


>   [⁠] U+2060 WORD JOINER [Cf]
<   [​] U+200B ZERO WIDTH SPACE [Cf]
+   [⁡] U+2061 FUNCTION APPLICATION [Cf]
-   [⁢] U+2062 INVISIBLE TIMES [Cf]
.   [⁣] U+2063 INVISIBLE SEPARATOR [Cf]
,   [﻿] U+FEFF ZERO WIDTH NO-BREAK SPACE [Cf]
[   [‌] U+200C ZERO WIDTH NON-JOINER [Cf]
]   [‍] U+200D ZERO WIDTH JOINER [Cf]


All other characters are silently ignored.


The meaning of original Brainfuck characters are as follows:


>   increment the data pointer (to point to the next cell to the right).
<   decrement the data pointer (to point to the next cell to the left).
+   increment (increase by one) the byte at the data pointer.
-   decrement (decrease by one) the byte at the data pointer.
.   output the byte at the data pointer.
,   accept one byte of input, storing its value in the byte at the
    data pointer.
[   if the byte at the data pointer is zero, then instead of moving
    the instruction pointer forward to the next command, jump it
    forward to the command after the matching ] command.
]   if the byte at the data pointer is nonzero, then instead of moving
    the instruction pointer forward to the next command, jump it back
    to the command after the matching [ command.


Takes a single positional argument: string of I<Anguish> code to evaluate.


See C<examples> directory of this distribution for example I<Anguish>
programs.


The C<U-FEFF> character also serves as a file
L<BOM|https://en.wikipedia.org/wiki/Byte_order_mark>, so avoid using it
as the first character in your file.


This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.


root

README

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


=begin React :component<CookieConsent> :id<CookieConsent> :buttonCaption("Got it!")
=para
This website uses cookies for analytics.
=end React


Anguish

NAME

SYNOPSIS

DESCRIPTION

EXPORTED SUBROUTINES

anguish

EXAMPLES

BUGS AND CAVEATS

AUTHOR

COPYRIGHT AND LICENSE

Acme::Anguish v1.1

Authors

License

Dependencies

Test Dependencies

Provides

Documentation