<pre class="ebnf">
rune_lit         = "'" ( unicode_value | byte_value ) "'" .
unicode_value    = unicode_char | little_u_value | big_u_value | escaped_char .
byte_value       = octal_byte_value | hex_byte_value .
octal_byte_value = `\` octal_digit octal_digit octal_digit .
hex_byte_value   = `\` "x" hex_digit hex_digit .
little_u_value   = `\` "u" hex_digit hex_digit hex_digit hex_digit .
big_u_value      = `\` "U" hex_digit hex_digit hex_digit hex_digit

C type _GoString_, described above. The _GoString_ type will be
automatically defined in the preamble. Note that there is no way for C
code to create a value of this type; this is only useful for passing
string values from Go to C and back to Go.

Using //export in a file places a restriction on the preamble:
since it is copied into two different C output files, it must not

[Cookie] now preserves double quotes surrounding a cookie value.
The new [Cookie.Quoted] field indicates whether the [Cookie.Value]

name: Pkg.go.dev bugs or feature requests
description: Issues or feature requests for the documentation site
title: "x/pkgsite: issue title"
labels: ["pkgsite"]
body:
  - type: markdown
    attributes:
      value: "Please answer these questions before submitting your issue. Thanks!"
  - type: input
    id: url
    attributes:
      label: "What is the URL of the page with the issue?"
    validations:
      required: true
  - type: input

		{"DATA", "0", "expect two operands for DATA"},
		{"DATA", "(0), 1", "expect /size for DATA argument"},
		{"DATA", "@B(SB)/4,0", "expected '(', found B"}, // Issue 23580.
		{"DATA", "·A(SB)/4,0", "DATA value must be an immediate constant or address"},
		{"DATA", "·B(SB)/4,$0", ""},
		{"DATA", "·C(SB)/5,$0", "bad int size for DATA argument: 5"},
		{"DATA", "·D(SB)/5,$0.0", "bad float size for DATA argument: 5"},

			if err.Error() != wantError {
				t.Fatalf("recovered panic: got %v, want %v", err.Error(), wantError)
			}
		default:
			t.Fatalf("unexpected panic value: %#v", err)
		}
	}()

	b.ReadFrom(new(negativeReader))
}

func TestWriteTo(t *testing.T) {
	var buf Buffer
	for i := 3; i < 30; i += 3 {

		// Corrupt foo.txt's final crc32 byte, in both
		// the file header and TOC. (0x7e -> 0x7f)
		b[0x11]++
		b[0x9d]++

		// TODO(bradfitz): add a new test that only corrupts
		// one of these values, and verify that that's also an
		// error. Currently, the reader code doesn't verify the
		// fileheader and TOC's crc32 match if they're both
		// non-zero and only the second line above, the TOC,
		// is what matters.

	}
	return record, nil
}

// validPAXRecord reports whether the key-value pair is valid where each
// record is formatted as:
//
//	"%d %s=%s\n" % (size, key, value)
//
// Keys and values should be UTF-8, but the number of bad writers out there
// forces us to be a more liberal.
// Thus, we only reject all keys with NUL, and only reject NULs in values
// for the PAX version of the USTAR string fields.

// invalid usage. opReadRuneX constants are chosen such that
// converted to int they correspond to the rune size that was read.
type readOp int8

// Don't use iota for these, as the values need to correspond with the
// names and comments, which is easier to see when being explicit.
const (
	opRead      readOp = -1 // Any other read operation.
	opInvalid   readOp = 0  // Non-read operation.

// allowedFormats determines which formats can be used.
// The value returned is the logical OR of multiple possible formats.
// If the value is FormatUnknown, then the input Header cannot be encoded
// and an error is returned explaining why.
//
// As a by-product of checking the fields, this function returns paxHdrs, which
// contain all fields that could not be directly encoded.