lars balker solutions, week 2

challenge-002/lars-balker/perl5/ch-1.pl

@@ -0,0 +1,44 @@
+# Write a script or one-liner to remove leading zeros from positive
+# numbers.
+
+# I chose to solve this in the strictest interpretation of the challenge:
+#   Make sure it's a number
+#   Make sure it's positive
+#   Don't remove the last 0 before period.
+
+use v5.10;
+use strict;
+use warnings;
+use Scalar::Util qw/looks_like_number/; # distributed with perl since 5.8
+
+sub remove_leading_zeros {
+    my $num = shift;
+    # ask perl if it thinks input is a number, and make sure it's positive
+    if (looks_like_number($num) && $num > 0) {
+        $num =~ s/^
+            (
+             0*      # match all leading 0s followed by
+             (?=0\.) # 0. (not included in match)
+             |
+             0*      # or just all leading 0s
+            )
+        //x;
+    }
+    $num;
+}
+
+if (@ARGV) {
+    say remove_leading_zeros shift;
+}
+else {
+    eval "use Test::More";
+    is(remove_leading_zeros("000000"),    "000000");
+    is(remove_leading_zeros("-0001"),     "-0001");
+    is(remove_leading_zeros("0001"),      "1");
+    is(remove_leading_zeros("0.001"),     "0.001");
+    is(remove_leading_zeros(".001"),      ".001");
+    is(remove_leading_zeros("000.001"),   "0.001");
+    is(remove_leading_zeros("001bar"),    "001bar");
+    is(remove_leading_zeros("fizzbuzz"),  "fizzbuzz");
+    done_testing();
+}

challenge-002/lars-balker/perl5/ch-2.pl

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+# Write a script that can convert integers to and from a base35
+# representation, using the characters 0-9 and A-Y.
+
+use v5.10;
+use strict;
+use warnings;
+
+sub to_base35 {
+    my $num = shift;
+    my $res = "";
+    my @val = (0..9, 'A'..'Y');
+    do {
+        $res .= $val[$num % 35];
+        $num = int($num / 35);
+    } while $num;
+    $res = reverse $res;
+    $res;
+}
+
+if (@ARGV) {
+    say to_base35 shift;
+}
+else {
+    eval "use Test::More";
+    is(to_base35(0),        "0");
+    is(to_base35(10),       "A");
+    is(to_base35(35),       "10");
+    is(to_base35(1337),     "137");
+    is(to_base35(20190401), "DFVXL");
+    done_testing();
+}

challenge-002/lars-balker/perl6/ch-1.pl6

@@ -0,0 +1,37 @@
+# Write a script or one-liner to remove leading zeros from positive
+# numbers.
+
+use v6;
+use Test;
+
+sub remove_leading_zeros($num) {
+    $num.subst(/^(
+                  0*                # match all leading 0s followed by
+                  <?before 0\.>     # 0. (not included in match)
+                  ||
+                  0*                # or just all leading 0s
+                  )
+               /, 
+               '');
+}
+
+# we let multi dispatch pick positive numbers
+multi sub MAIN(Numeric $num where $num > 0) {
+    say remove_leading_zeros($num);
+}
+
+# if not a positive number, just echo input
+multi sub MAIN($other) {
+    say $other;
+}
+
+# test if no input
+multi sub MAIN() {
+    # we only test the legal number input, because other input is
+    # sorted out by multi methods
+    is(remove_leading_zeros("0001"),      "1");
+    is(remove_leading_zeros("0.001"),     "0.001");
+    is(remove_leading_zeros(".001"),      ".001");
+    is(remove_leading_zeros("000.001"),   "0.001");
+    done-testing();
+}

challenge-002/lars-balker/perl6/ch-2.pl6

@@ -0,0 +1,23 @@
+# Write a script that can convert integers to and from a base35
+# representation, using the characters 0-9 and A-Y.
+
+use v6;
+use Test;
+
+sub to_base35(Int $num) {
+    return $num.base(35);
+}
+
+multi sub MAIN($num) {
+    say to_base35($num);
+}
+
+# kinda love this ARGV multi method dispatching in perl6
+multi sub MAIN() {
+    is(to_base35(0),        "0");
+    is(to_base35(10),       "A");
+    is(to_base35(35),       "10");
+    is(to_base35(1337),     "137");
+    is(to_base35(20190401), "DFVXL");
+    done-testing();
+}