Solution to task 1

1 files changed, 28 insertions, 0 deletions

diff --git a/challenge-084/jo-37/perl/ch-1.pl b/challenge-084/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..f6277ee546
--- /dev/null
+++ b/challenge-084/jo-37/perl/ch-1.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/perl
+
+use Test2::V0;
+use Math::Utils 'copysign';
+
+# Reverse the decimal representation of a given number into a signed
+# long (32-bit) value.  Return zero if the result does not fit.
+sub reverse_l {
+	pop @{[map $_ * (unpack('l', pack 'l', $_) == $_),
+		map copysign(scalar(reverse abs int), $_), shift]};
+}
+
+is reverse_l( 1234),          4321, 'Example 1';
+is reverse_l(-1234),         -4321, 'Example 2';
+is reverse_l( 1231230512),       0, 'Example 3';
+is reverse_l(-8463847412),  -2**31, 'negative limit';
+is reverse_l( 7463847412), 2**31-1, 'positive limit';
+is reverse_l(-9463847412),       0, 'below negative limit';
+is reverse_l( 8463847412),       0, 'above positive limit';
+is reverse_l( 074),              6, 'accept octal';
+is reverse_l( 470),             74, 'do not generate octal';
+is reverse_l( 0xf0),            42, 'accept hex';
+is reverse_l( 123.456),        321, 'ignore part after decimal point';
+is reverse_l(-0),                0, 'signless zero';
+
+done_testing;
+
+# vi:ts=4: