</pre>

<p>
Productions are expressions constructed from terms and the following
operators, in increasing precedence:
</p>
<pre class="grammar">
|   alternation
()  grouping
[]  option (0 or 1 times)
{}  repetition (0 to n times)
</pre>

<p>
Lower-case production names are used to identify lexical tokens.
Non-terminals are in CamelCase. Lexical tokens are enclosed in
double quotes <code>""</code> or back quotes <code>``</code>.

because it documents the full list of known GODEBUG settings,
which are tied to a specific release.
-->

## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.
If code depends on buggy (including insecure) behavior,
then fixing the bug will break that code.
New features can also have similar impacts:

		for _, tt := range compareTests {
			eql := Equal(tt.a, tt.b)
			if eql != (tt.i == 0) {
				t.Errorf(`Equal(%q, %q) = %v`, tt.a, tt.b, eql)
			}
		}
	})
	if allocs > 0 {
		t.Errorf("Equal allocated %v times", allocs)
	}
}

func TestEqualExhaustive(t *testing.T) {
	var size = 128
	if testing.Short() {
		size = 32
	}
	a := make([]byte, size)
	b := make([]byte, size)
	b_init := make([]byte, size)

The [Repeat] function returns a new slice that repeats the

func TestModTime(t *testing.T) {
	var testTime = time.Date(2009, time.November, 10, 23, 45, 58, 0, time.UTC)
	fh := new(FileHeader)
	fh.SetModTime(testTime)
	outTime := fh.ModTime()
	if !outTime.Equal(testTime) {
		t.Errorf("times don't match: got %s, want %s", outTime, testTime)
	}
}

func testHeaderRoundTrip(fh *FileHeader, wantUncompressedSize uint32, wantUncompressedSize64 uint64, t *testing.T) {
	fi := fh.FileInfo()

</pre>

<p>
Productions are expressions constructed from terms and the following
operators, in increasing precedence:
</p>
<pre class="grammar">
|   alternation
()  grouping
[]  option (0 or 1 times)
{}  repetition (0 to n times)
</pre>

<p>
Lowercase production names are used to identify lexical (terminal) tokens.
Non-terminals are in CamelCase. Lexical tokens are enclosed in

The new [ParseCookie] function parses a Cookie header value and
returns all the cookies which were set in it. Since the same cookie
name can appear multiple times the returned Values can contain
more than one value for a given key.

The new [ParseSetCookie] function parses a Set-Cookie header value and