Initial Commit

go/leap/README.md

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+# Leap
+
+Write a program that will take a year and report if it is a leap year.
+
+The tricky thing here is that a leap year occurs:
+
+```plain
+on every year that is evenly divisible by 4
+  except every year that is evenly divisible by 100
+    unless the year is also evenly divisible by 400
+```
+
+For example, 1997 is not a leap year, but 1996 is.  1900 is not a leap
+year, but 2000 is.
+
+If your language provides a method in the standard library that does
+this look-up, pretend it doesn't exist and implement it yourself.
+
+## Notes
+
+For a delightful, four minute explanation of the whole leap year
+phenomenon, go watch [this youtube video][video].
+
+[video]: http://www.youtube.com/watch?v=xX96xng7sAE
+
+To run the tests simply run the command `go test` in the exercise directory.
+
+If the test suite contains benchmarks, you can run these with the `-bench`
+flag:
+
+    go test -bench .
+
+For more detailed info about the Go track see the [help
+page](http://help.exercism.io/getting-started-with-go.html).
+
+## Source
+
+JavaRanch Cattle Drive, exercise 3 [view source](http://www.javaranch.com/leap.jsp)

go/leap/cases_test.go

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+package leap
+
+// Source: exercism/x-common
+// Commit: 945d08e Merge pull request #50 from soniakeys/master
+
+var testCases = []struct {
+	year        int
+	expected    bool
+	description string
+}{
+	{1996, true, "leap year"},
+	{1997, false, "non-leap year"},
+	{1998, false, "non-leap even year"},
+	{1900, false, "century"},
+	{2400, true, "fourth century"},
+	{2000, true, "Y2K"},
+}

go/leap/leap.go

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+package leap
+
+// TestVersion is an exercism thing.
+const TestVersion = 1
+
+// IsLeapYear returns whether the given year is a leap year.
+func IsLeapYear(year int) bool {
+	if year%4 != 0 {
+		return false
+	}
+	if year%400 == 0 {
+		return true
+	}
+	return year%100 != 0
+}

go/leap/leap_test.go

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+package leap
+
+import "testing"
+
+// Define a function IsLeapYear(int) bool.
+//
+// Also define an exported TestVersion with a value that matches
+// the internal testVersion here.
+
+const testVersion = 1
+
+// Retired testVersions
+// (none) 4a9e144a3c5dc0d9773f4cf641ffe3efe48641d8
+
+func TestLeapYears(t *testing.T) {
+	if TestVersion != testVersion {
+		t.Fatalf("Found TestVersion = %v, want %v", TestVersion, testVersion)
+	}
+	for _, test := range testCases {
+		observed := IsLeapYear(test.year)
+		if observed != test.expected {
+			t.Fatalf("IsLeapYear(%d) = %t, want %t (%s)",
+				test.year, observed, test.expected, test.description)
+		}
+	}
+}
+
+func BenchmarkLeapYears(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, test := range testCases {
+			IsLeapYear(test.year)
+		}
+	}
+}