Merge pull request #6658 from PerlMonk-Athanasius/branch-for-challenge-179

Perl & Raku solutions to Tasks 1 & 2 for Week 179

4 files changed, 904 insertions, 0 deletions

diff --git a/challenge-179/athanasius/perl/ch-1.pl b/challenge-179/athanasius/perl/ch-1.pl
new file mode 100644
index 0000000000..bf97bafc48
--- /dev/null
+++ b/challenge-179/athanasius/perl/ch-1.pl
@@ -0,0 +1,315 @@
+#!perl
+
+###############################################################################
+=comment
+
+Perl Weekly Challenge 179
+=========================
+
+TASK #1
+-------
+*Ordinal Number Spelling*
+
+Submitted by: Mohammad S Anwar
+
+You are given a positive number, $n.
+
+Write a script to spell the ordinal number.
+
+For example,
+
+  11 => eleventh
+  62 => sixty-second
+  99 => ninety-ninth
+
+=cut
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2022 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=comment
+
+Assumptions
+-----------
+1. Ordinal names use the short scale. [1]
+2. Valid input is any integer $n in the range 0 < $n <= (2^64 - 2^10).
+
+Interface
+---------
+If $n is not supplied on the command line, the in-file test suite is run
+instead.
+
+Note
+----
+Script output tested under Windows 8.1 using Perl v5.32.1.
+
+Reference
+---------
+[1] "Long and short scales", Wikipedia,
+     https://en.wikipedia.org/wiki/Long_and_short_scales
+
+=cut
+#==============================================================================
+
+use strict;
+use warnings;
+use Const::Fast;
+use Regexp::Common qw( number );
+use Test::More;
+
+const my $MAX   => 18_446_744_073_709_550_592;                    # 2^64 - 2^10
+
+const my %UNITS =>
+(
+    CARDINAL    =>
+    [ '', qw( one   two    three four   five  six   seven   eight  nine  ) ],
+    ORDINAL     =>
+    [ '', qw( first second third fourth fifth sixth seventh eighth ninth ) ],
+);
+
+const my @TEENS => qw( ten     eleven  twelve    thirteen fourteen
+                       fifteen sixteen seventeen eighteen nineteen );
+
+const my @TENS  => '', '', qw( twenty thirty  forty  fifty
+                               sixty  seventy eighty ninety );
+
+const my @LARGE => qw( thousand million     billion
+                       trillion quadrillion quintillion );
+
+const my $USAGE =>
+"Usage:
+  perl $0 <n>
+  perl $0
+
+    <n>    A natural number below 2^64 - 2^10\n";
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    $| = 1;
+    print "\nChallenge 179, Task #1: Ordinal Number Spelling (Perl)\n\n";
+}
+
+#==============================================================================
+MAIN:
+#==============================================================================
+{
+    my $n = parse_command_line();
+
+    if (defined $n)
+    {
+        printf "Input:  %s\n", add_commas( $n );
+        printf "Output: %s\n", ordinal   ( $n );
+    }
+    else
+    {
+        run_tests();
+    }
+}
+
+#------------------------------------------------------------------------------
+sub ordinal
+#------------------------------------------------------------------------------
+{
+    my ($n) = @_;
+
+    $n = '0' x ((3 - (length( $n ) % 3)) % 3) . $n;  # Prepend zeroes
+
+    my @triples  = $n =~ / (\d{3}) /gx;              # Group digits
+    my $ls_digs  = $triples[ -1 ];                   # Least significant digits
+    my $hundreds = hundreds( pop @triples, 1 );
+
+    my   @ordinal;
+    push @ordinal, $hundreds if $hundreds;
+
+    for (my $index = 0; @triples; ++$index)
+    {
+        if ((my $n = pop @triples) > 0)
+        {
+            push @ordinal, hundreds( $n, 0 ) . ' ' . $LARGE[ $index ];
+        }
+    }
+
+    return format_ordinal( \@ordinal, $ls_digs );
+}
+
+#------------------------------------------------------------------------------
+sub hundreds
+#------------------------------------------------------------------------------
+{
+    my ($n, $ordinal)     = @_;
+    my ($hundreds, $tens) = $n =~ / ^ (\d) (\d{2}) $ /x;
+    my  $name             = tens( $tens, $ordinal );
+
+    if ($hundreds > 0)
+    {
+        $name = $UNITS{ CARDINAL }[ $hundreds ] . ' hundred' .
+                (($tens == 0) ? '' : ($name ? " and $name" : 'th'));
+    }
+
+    return $name;
+}
+
+#------------------------------------------------------------------------------
+sub tens
+#------------------------------------------------------------------------------
+{
+    my ($n, $ordinal) = @_;
+
+    return '' if $n == 0;
+
+    my ($tens, $units) = $n =~ / ^ (\d) (\d) $ /x;
+
+    my  $key  =  $ordinal    ? 'ORDINAL' : 'CARDINAL';
+    my  $name = ($tens == 1) ? $TEENS[ $units ] . ($ordinal ? 'th' : '')
+                             : $UNITS{ $key }[ $units ];
+
+    if ($tens > 1)
+    {
+        my $tens_name = $TENS[ $tens ];
+
+        if    ($units > 0)
+        {
+            $name = $tens_name . '-' . $name;
+        }
+        elsif ($ordinal)
+        {
+            $name = substr( $tens_name, 0, -1 ) . 'ieth';
+        }
+        else
+        {
+            $name = $tens_name;
+        }
+    }
+
+    return $name;
+}
+
+#-------------------------------------------------------------------------------
+sub format_ordinal
+#-------------------------------------------------------------------------------
+{
+    my ($ord_array, $ls_digs) = @_;
+    my  $ordinal;
+
+    if    (scalar @$ord_array == 1)
+    {
+        $ordinal = $ord_array->[ 0 ] . (($ls_digs % 100 == 0) ? 'th' : '');
+    }
+    elsif ($ls_digs % 100 == 0)
+    {
+        $ordinal = join( ' ', reverse @$ord_array ) . 'th';
+    }   
+    elsif ($ls_digs =~ / ^ 0 /x)
+    {
+        $ordinal = join( ' ', reverse @$ord_array[ 1 .. $#$ord_array ] ) .
+                   ' and ' . $ord_array->[ 0 ];
+    }
+    else
+    {
+        $ordinal = join ' ', reverse @$ord_array;
+    }
+
+    return $ordinal;
+}
+
+#-------------------------------------------------------------------------------
+sub add_commas
+#-------------------------------------------------------------------------------
+{
+    my ($number) = @_;
+
+    # Regex from perlfaq5: "How can I output my numbers with commas added?"
+
+    return $number =~ s/(^\d+?(?=(?>(?:\d{3})+)(?!\d))|\G\d{3}(?=\d))/$1,/gr;
+}
+
+#------------------------------------------------------------------------------
+sub parse_command_line
+#------------------------------------------------------------------------------
+{
+    my $args = scalar @ARGV;
+       $args == 0 and return;           # Run tests
+       $args == 1 or error( "Expected 1 command line argument, found $args" );
+
+    my $n = $ARGV[ 0 ];
+
+    $n =~ / ^ $RE{num}{int} $ /x
+                  or error( qq["$n" is not a valid integer] );
+
+    $n >  0       or error( "$n is not a natural number" );
+
+    $n <= $MAX    or error( "$n is too large" );
+
+    return $n + 0;                      # Normalise (remove any initial zeroes)
+}
+
+#------------------------------------------------------------------------------
+sub error
+#------------------------------------------------------------------------------
+{
+    my ($message) = @_;
+
+    die "ERROR: $message\n$USAGE";
+}
+
+#------------------------------------------------------------------------------
+sub run_tests
+#------------------------------------------------------------------------------
+{
+    while (my $line = <DATA>)
+    {
+        chomp $line;
+
+        $line =~ s/ ^ (\s+) //x;                    # Remove initial whitespace
+
+        my ($n, $expected) = split /\s+/, $line, 2;
+        my  $test_name     = sprintf '(%s)', add_commas( $n );
+
+        is ordinal( $n ), $expected, $test_name;
+    }
+
+    done_testing;
+}
+
+###############################################################################
+
+__DATA__
+                   1 first
+                   2 second
+                   3 third
+                   4 fourth
+                  10 tenth
+                  11 eleventh
+                  19 nineteenth
+                  20 twentieth
+                  21 twenty-first
+                  37 thirty-seventh
+                  62 sixty-second
+                  99 ninety-ninth
+                 100 one hundredth
+                 201 two hundred and first
+                 310 three hundred and tenth
+                 425 four hundred and twenty-fifth
+                 590 five hundred and ninetieth
+                2345 two thousand three hundred and forty-fifth
+                5000 five thousandth
+                6100 six thousand one hundredth
+              100000 one hundred thousandth
+              101001 one hundred and one thousand and first
+              101110 one hundred and one thousand one hundred and tenth
+             1000069 one million and sixty-ninth
+             9000999 nine million nine hundred and ninety-ninth
+             9001000 nine million one thousandth
+          6000000000 six billionth
+          6000000050 six billion and fiftieth
+          6000007000 six billion seven thousandth
+          7000000003 seven billion and third
+          1034000890 one billion thirty-four million eight hundred and ninetieth
+ 1000000000000000000 one quintillionth
+ 1000000000000001343 one quintillion one thousand three hundred and forty-third
+18446744073709550592 eighteen quintillion four hundred and forty-six quadrillion seven hundred and forty-four trillion seventy-three billion seven hundred and nine million five hundred and fifty thousand five hundred and ninety-second
diff --git a/challenge-179/athanasius/perl/ch-2.pl b/challenge-179/athanasius/perl/ch-2.pl
new file mode 100644
index 0000000000..6c841c9cd1
--- /dev/null
+++ b/challenge-179/athanasius/perl/ch-2.pl
@@ -0,0 +1,152 @@
+#!perl
+
+###############################################################################
+=comment
+
+Perl Weekly Challenge 179
+=========================
+
+TASK #2
+-------
+*Unicode Sparkline*
+
+Submitted by: Mohammad S Anwar
+
+You are given a list of positive numbers, @n.
+
+Write a script to print sparkline in Unicode for the given list of numbers.
+
+=cut
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2022 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=comment
+
+Assumptions
+-----------
+1. Strictly speaking, sparklines are line charts [2]. However, the Rosetta Code
+   task "Sparkline in unicode" [3] specifies output in the form of bar charts
+   drawn using the 8 Unicode characters U+2581 through U+2588. Given that the
+   Task description calls for a "sparkline in Unicode", the Rosetta Code speci-
+   fication is adopted here.
+
+2. In a normal bar chart, the y axis should start at zero; otherwise, it is a
+   truncated (or torn) graph, which "can create the impression of important
+   change where there is relatively little change" [1]. A sparkline, on the
+   other hand, "presents the general shape of the variation...in some measure-
+   ment" and so should normally not start at zero. The elements in a sparkline
+   range in value between the minimum and maximum data points only.
+
+Note
+----
+Script output tested under Windows 8.1 using Perl v5.22.4 running under Cygwin
+2.8.2-1.
+
+References
+----------
+[1] "Misleading graph", Wikipedia,
+     https://en.wikipedia.org/wiki/Misleading_graph
+[2] "Sparkline", Wikipedia, https://en.wikipedia.org/wiki/Sparkline
+[3] "Sparkline in unicode", Rosetta Code,
+     https://rosettacode.org/wiki/Sparkline_in_unicode
+
+=cut
+#==============================================================================
+
+use strict;
+use warnings;
+use utf8;
+use Const::Fast;
+use List::Util     qw( max min );
+use Regexp::Common qw( number );
+
+const my @CHARS => qw( ▁ ▂ ▃ ▄ ▅ ▆ ▇ █ );
+const my $USAGE =>
+"Usage:
+  perl $0 [<n> ...]
+
+    [<n> ...]    One or more positive numbers\n";
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    $| = 1;
+    binmode(STDOUT, ':utf8');
+    print "\nChallenge 179, Task #2: Unicode Sparkline (Perl)\n\n";
+}
+
+#==============================================================================
+MAIN:
+#==============================================================================
+{
+    my @n = parse_command_line();
+
+    printf "Input:  %s\n\n", join ', ', @n;
+
+    my @sparkline;
+    my $min   = min @n;
+    my $max   = max @n;
+    my $range = $max - $min;
+
+    if ($range == 0)
+    {
+        @sparkline = ($CHARS[ 0 ]) x scalar( @n );
+    }
+    else
+    {
+        for my $n (@n)
+        {
+            my $idx = 7;
+
+            for my $i (1 .. 7)
+            {
+                if (($n - $min) < ($i * $range / 8))
+                {
+                    $idx = $i - 1;
+                    last;
+                }
+            }
+
+            push @sparkline, $CHARS[ $idx ];
+        }
+    }
+
+    printf "Output: %s\n",   join '', @sparkline;
+}
+
+#------------------------------------------------------------------------------
+sub parse_command_line
+#------------------------------------------------------------------------------
+{
+    my $args = scalar @ARGV;
+       $args == 0 and error( 'No command line arguments found' );
+
+    my @n = @ARGV;
+
+    for my $n (@n)
+    {
+        $n =~ s/ (,) $ //x;          # Remove trailing comma separator (if any)
+
+        $n =~ / ^ $RE{num}{real} $ /x
+                  or  error( qq["$n" is not a valid real number] );
+        $n >= 0   or  error( qq["$n" is not a positive number]   );
+    }
+
+    return @n;
+}
+
+#------------------------------------------------------------------------------
+sub error
+#------------------------------------------------------------------------------
+{
+    my ($message) = @_;
+
+    die "ERROR: $message\n$USAGE";
+}
+
+###############################################################################
diff --git a/challenge-179/athanasius/raku/ch-1.raku b/challenge-179/athanasius/raku/ch-1.raku
new file mode 100644
index 0000000000..c492a335c1
--- /dev/null
+++ b/challenge-179/athanasius/raku/ch-1.raku
@@ -0,0 +1,285 @@
+use v6d;
+
+###############################################################################
+=begin comment
+
+Perl Weekly Challenge 179
+=========================
+
+TASK #1
+-------
+*Ordinal Number Spelling*
+
+Submitted by: Mohammad S Anwar
+
+You are given a positive number, $n.
+
+Write a script to spell the ordinal number.
+
+For example,
+
+  11 => eleventh
+  62 => sixty-second
+  99 => ninety-ninth
+
+=end comment
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2022 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=begin comment
+
+Assumptions
+-----------
+1. Ordinal names use the short scale. [1]
+2. Valid input is any integer $n in the range 0 < $n < 10^21.
+
+Interface
+---------
+If $n is not supplied on the command line, the in-file test suite is run
+instead.
+
+Note
+----
+Script output tested under Windows 8.1 using Rakudo v2022.04 (implementing Raku
+v6.d).
+
+Reference
+---------
+[1] "Long and short scales", Wikipedia,
+     https://en.wikipedia.org/wiki/Long_and_short_scales
+
+=end comment
+#==============================================================================
+
+use Test;
+
+my constant $MAX   = 10 ** 21 - 1;                    # One sextillion less one
+
+my constant %UNITS = 
+
+    CARDINAL =>
+    [ '', |< one   two    three four   five  six   seven   eight  nine  > ],
+    ORDINAL  =>
+    [ '', |< first second third fourth fifth sixth seventh eighth ninth > ];
+
+my constant @TEENS = < ten     eleven  twelve    thirteen fourteen
+                       fifteen sixteen seventeen eighteen nineteen >;
+
+my constant @TENS  = '', '', |< twenty thirty  forty  fifty
+                                sixty  seventy eighty ninety >;
+
+my constant @LARGE = < thousand million     billion
+                       trillion quadrillion quintillion >;
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    "\nChallenge 179, Task #1: Ordinal Number Spelling (Raku)\n".put;
+}
+
+#==============================================================================
+multi sub MAIN
+(
+    UInt:D $n where { 0 < $n <= $MAX }   #= A natural number below 1 sextillion
+)
+#==============================================================================
+{
+    my UInt $num = $n + 0;              # Normalise (remove any initial zeroes)
+
+    "Input:  %s\n".printf: add-commas( $num );
+    "Output: %s\n".printf: ordinal\  ( $num );
+}
+
+#==============================================================================
+multi sub MAIN()
+#==============================================================================
+{
+    run-tests;
+}
+
+#-------------------------------------------------------------------------------
+sub ordinal( UInt:D $n where * > 0 --> Str:D )
+#-------------------------------------------------------------------------------
+{
+    my Str $num      = '0' x ((3 - $n.chars % 3) % 3) ~ $n;     # Prepend zeroes
+    my Str @triples  = ($num ~~ m:g/ (\d ** 3) /).map: { .Str };  # Group digits
+    my Str $ls-digs  = @triples[ *-1 ];               # Least significant digits
+    my Str $hundreds = hundreds( @triples.pop, True );
+    my Str @ordinal;
+           @ordinal.push: $hundreds if $hundreds;
+
+    loop (my UInt $index = 0; @triples.elems > 0; ++$index)
+    {
+        if (my Str $n = @triples.pop) > 0
+        {
+            @ordinal.push: hundreds( $n, False ) ~ ' ' ~ @LARGE[ $index ];
+        }
+    }
+
+    return format-ordinal( @ordinal, $ls-digs );
+}
+
+#------------------------------------------------------------------------------
+sub hundreds( Str:D $n, Bool:D $ordinal --> Str:D )
+#------------------------------------------------------------------------------
+{
+    my Str ($hundreds, $tens) = ($n ~~ / ^ (\d) (\d ** 2) $ /).map: { .Str };
+    my Str  $name             = tens( $tens, $ordinal );
+
+    if $hundreds > 0
+    {
+        $name = %UNITS< CARDINAL >[ $hundreds ] ~ ' hundred' ~
+                (($tens == 0) ?? '' !! ($name ?? " and $name" !! 'th'));
+    }
+
+    return $name;
+}
+
+#------------------------------------------------------------------------------
+sub tens( Str:D $n, Bool:D $ordinal --> Str:D )
+#------------------------------------------------------------------------------
+{
+    return '' if $n.Int == 0;
+
+    my Str ($tens, $units) = ($n ~~ / ^ (\d) (\d) $ /).map: { .Str };
+
+    my Str  $key  =  $ordinal    ?? 'ORDINAL' !! 'CARDINAL';
+    my Str  $name = ($tens == 1) ?? @TEENS[ $units ] ~ ($ordinal ?? 'th' !! '')
+                                 !! %UNITS{ $key }[ $units ];
+
+    if $tens > 1
+    {
+        my Str $tens-name = @TENS[ $tens ];
+
+        if    $units > 0
+        {
+            $name = $tens-name ~ '-' ~ $name;
+        }
+        elsif $ordinal
+        {
+            $name = $tens-name.substr( 0, $tens-name.chars - 1 ) ~ 'ieth';
+        }
+        else
+        {
+            $name = $tens-name;
+        }
+    }
+
+    return $name;
+}
+
+#-------------------------------------------------------------------------------
+sub format-ordinal( Array:D[Str:D] $ord-array, Str:D $ls-digs --> Str:D )
+#-------------------------------------------------------------------------------
+{
+    my Str $ordinal;
+
+    if    @$ord-array.elems == 1
+    {
+        $ordinal = $ord-array[ 0 ] ~ ($ls-digs %% 100 ?? 'th' !! '');
+    }
+    elsif $ls-digs %% 100
+    {
+        $ordinal = $ord-array.reverse.join( ' ' ) ~ 'th';
+    }   
+    elsif $ls-digs ~~ / ^ 0 /
+    {
+        $ordinal = $ord-array[ 1 .. $ord-array.end ].reverse.join( ' ' ) ~
+                   ' and ' ~ $ord-array[ 0 ];
+    }
+    else
+    {
+        $ordinal = $ord-array.reverse.join: ' ';
+    }
+
+    return $ordinal;
+}
+
+#-------------------------------------------------------------------------------
+# From https://rosettacode.org/wiki/Commatizing_numbers#Raku
+#
+sub add-commas( $s, :$at = 0, :$ins = ',', :$by = 3 )
+#-------------------------------------------------------------------------------
+{
+    $s.subst: :continue( $at ), :1st, / <[1..9]> <[0..9]>* /,
+        *.flip.comb( / <{ ". ** 1..$by" }> / ).join( $ins ).flip;
+}
+
+#------------------------------------------------------------------------------
+sub run-tests()
+#------------------------------------------------------------------------------
+{
+    for test-data.lines -> Str $line
+    {
+        my Str $test = $line.chomp;
+
+        $test ~~ s/ ^ (\s+) //;                     # Remove initial whitespace
+
+        my Str ($n, $expected) =  $test.split: /\s+/, 2, :skip-empty;
+        my Str  $test-name     = '(%s)'.sprintf: add-commas( $n );
+
+        is ordinal( $n.Int ), $expected, $test-name;
+    }
+
+    done-testing;
+}
+
+#------------------------------------------------------------------------------
+sub test-data()
+#------------------------------------------------------------------------------
+{
+    return q:to/END/;
+                    1 first
+                    2 second
+                    3 third
+                    4 fourth
+                   10 tenth
+                   11 eleventh
+                   19 nineteenth
+                   20 twentieth
+                   21 twenty-first
+                   37 thirty-seventh
+                   62 sixty-second
+                   99 ninety-ninth
+                  100 one hundredth
+                  201 two hundred and first
+                  310 three hundred and tenth
+                  425 four hundred and twenty-fifth
+                  590 five hundred and ninetieth
+                 2345 two thousand three hundred and forty-fifth
+                 5000 five thousandth
+                 6100 six thousand one hundredth
+               100000 one hundred thousandth
+               101001 one hundred and one thousand and first
+               101110 one hundred and one thousand one hundred and tenth
+              1000069 one million and sixty-ninth
+              9000999 nine million nine hundred and ninety-ninth
+              9001000 nine million one thousandth
+           6000000000 six billionth
+           6000000050 six billion and fiftieth
+           6000007000 six billion seven thousandth
+           7000000003 seven billion and third
+           1034000890 one billion thirty-four million eight hundred and ninetieth
+  1000000000000000000 one quintillionth
+  1000000000000001343 one quintillion one thousand three hundred and forty-third
+999999999999999999999 nine hundred and ninety-nine quintillion nine hundred and ninety-nine quadrillion nine hundred and ninety-nine trillion nine hundred and ninety-nine billion nine hundred and ninety-nine million nine hundred and ninety-nine thousand nine hundred and ninety-ninth
+END
+}
+
+#------------------------------------------------------------------------------
+sub USAGE()
+#------------------------------------------------------------------------------
+{
+    my Str $usage = $*USAGE;
+
+    $usage ~~ s:g/ ($*PROGRAM-NAME) /raku $0/;
+
+    $usage.put;
+}
+
+###############################################################################
diff --git a/challenge-179/athanasius/raku/ch-2.raku b/challenge-179/athanasius/raku/ch-2.raku
new file mode 100644
index 0000000000..fd67f4222d
--- /dev/null
+++ b/challenge-179/athanasius/raku/ch-2.raku
@@ -0,0 +1,152 @@
+use v6d;
+
+###############################################################################
+=begin comment
+
+Perl Weekly Challenge 179
+=========================
+
+TASK #2
+-------
+*Unicode Sparkline*
+
+Submitted by: Mohammad S Anwar
+
+You are given a list of positive numbers, @n.
+
+Write a script to print sparkline in Unicode for the given list of numbers.
+
+=end comment
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2022 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=begin comment
+
+Assumptions
+-----------
+1. Strictly speaking, sparklines are line charts [2]. However, the Rosetta Code
+   task "Sparkline in unicode" [3] specifies output in the form of bar charts
+   drawn using the 8 Unicode characters U+2581 through U+2588. Given that the
+   Task description calls for a "sparkline in Unicode", the Rosetta Code speci-
+   fication is adopted here.
+
+2. In a normal bar chart, the y axis should start at zero; otherwise, it is a
+   truncated (or torn) graph, which "can create the impression of important
+   change where there is relatively little change" [1]. A sparkline, on the
+   other hand, "presents the general shape of the variation...in some measure-
+   ment" and so should normally not start at zero. The elements in a sparkline
+   range in value between the minimum and maximum data points only.
+
+Note
+----
+Script output tested under Windows 8.1 using Rakudo v2022.04 (implementing Raku
+v6.d) running under Cygwin 2.8.2-1.
+
+References
+----------
+[1] "Misleading graph", Wikipedia,
+     https://en.wikipedia.org/wiki/Misleading_graph
+[2] "Sparkline", Wikipedia, https://en.wikipedia.org/wiki/Sparkline
+[3] "Sparkline in unicode", Rosetta Code,
+     https://rosettacode.org/wiki/Sparkline_in_unicode
+
+=end comment
+#==============================================================================
+
+my constant @CHARS = < ▁ ▂ ▃ ▄ ▅ ▆ ▇ █ >;
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    "\nChallenge 179, Task #2: Unicode Sparkline (Raku)\n".put;
+}
+
+#==============================================================================
+sub MAIN
+(
+    *@n where { .elems > 0 }                    #= One or more positive numbers
+)
+#==============================================================================
+{
+    my Real @nums  = parse-command-line( @n );
+
+    "Input:  %s\n\n".printf: @nums.join: ', ';
+
+    my Str  @sparkline;
+    my Real $min   = @nums.min;
+    my Real $max   = @nums.max;
+    my Real $range = $max - $min;
+
+    if $range
+    {
+        for @nums -> Real $n
+        {
+            my UInt $idx = 7;
+
+            for 1 .. 7 -> UInt $i
+            {
+                if ($n - $min) < ($i * $range / 8)
+                {
+                    $idx = $i - 1;
+                    last;
+                }
+            }
+
+            @sparkline.push: @CHARS[ $idx ];
+        }
+    }
+    else
+    {
+        @sparkline = @CHARS[ 0 ] xx @nums.elems;
+    }
+
+    "Output: %s\n".printf: @sparkline.join;
+}
+
+#------------------------------------------------------------------------------
+sub parse-command-line( *@n --> Array:D[Real:D] )
+#------------------------------------------------------------------------------
+{
+    my Real @nums;
+
+    for @n
+    {
+        my Str $n = S/ (\,) $ //;    # Remove trailing comma separator (if any)
+
+        $n.Real ~~ Failure and error( qq["$n" is not a valid real number] );
+        $n.Real >= 0       or  error( qq["$n" is not a positive number]   );
+
+        @nums.push: $n.Real;
+    }
+
+    return @nums;
+}
+
+#------------------------------------------------------------------------------
+sub error( Str:D $message )
+#------------------------------------------------------------------------------
+{
+    "ERROR: $message".put;
+
+    USAGE();
+
+    exit 0;
+}
+
+#------------------------------------------------------------------------------
+sub USAGE()
+#------------------------------------------------------------------------------
+{
+    my Str $usage = $*USAGE;
+
+    $usage ~~ s:g/ ($*PROGRAM-NAME) /raku $0/;
+
+    $usage.put;
+}
+
+###############################################################################