\n   U+000A line feed or newline
\r   U+000D carriage return
\t   U+0009 horizontal tab
\v   U+000B vertical tab
\\   U+005C backslash
\'   U+0027 single quote  (valid escape only within rune literals)
\"   U+0022 double quote  (valid escape only within string literals)
</pre>

<p>
All other sequences starting with a backslash are illegal inside rune literals.
</p>
<pre class="ebnf">

	//	return append(b, make([]byte, n)...)
	// This avoids unnecessary zero-ing of the first len(b) bytes of the
	// allocated slice, but this pattern causes b to escape onto the heap.
	//
	// Instead use the append-make pattern with a nil slice to ensure that
	// we allocate buffers rounded up to the closest size class.
	c := len(b) + n // ensure enough space for n elements

			i+1, i+1, n.C,
		)
	}
	fmt.Fprintf(&b, "#line 1 \"completed\"\n"+
		"int __cgo__1 = __cgo__2;\n")

	// We need to parse the output from this gcc command, so ensure that it
	// doesn't have any ANSI escape sequences in it. (TERM=dumb is
	// insufficient; if the user specifies CGO_CFLAGS=-fdiagnostics-color,
	// GCC will ignore TERM, and GCC can also be configured at compile-time
	// to ignore TERM.)

pkg encoding/pem, type Block struct, Headers map[string]string
pkg encoding/pem, type Block struct, Type string
pkg encoding/xml, const Header ideal-string
pkg encoding/xml, func CopyToken(Token) Token
pkg encoding/xml, func Escape(io.Writer, []uint8)
pkg encoding/xml, func Marshal(interface{}) ([]uint8, error)
pkg encoding/xml, func MarshalIndent(interface{}, string, string) ([]uint8, error)
pkg encoding/xml, func NewDecoder(io.Reader) *Decoder

			}
		}
	}
	var tokens []Token
	// Scan to newline. Backslashes escape newlines.
	for tok != '\n' {
		if tok == scanner.EOF {
			in.Error("missing newline in definition for macro:", name)
		}
		if tok == '\\' {
			tok = in.Stack.Next()
			if tok != '\n' && tok != '\\' {
				in.Error(`can only escape \ or \n in definition for macro:`, name)
			}
		}

\n   U+000A line feed or newline
\r   U+000D carriage return
\t   U+0009 horizontal tab
\v   U+000B vertical tab
\\   U+005C backslash
\'   U+0027 single quote  (valid escape only within rune literals)
\"   U+0022 double quote  (valid escape only within string literals)
</pre>

<p>
An unrecognized character following a backslash in a rune literal is illegal.
</p>

<pre class="ebnf">

pkg regexp/syntax, const ErrInvalidCharClass = "invalid character class"
pkg regexp/syntax, const ErrInvalidCharRange = "invalid character class range"
pkg regexp/syntax, const ErrInvalidEscape = "invalid escape sequence"
pkg regexp/syntax, const ErrInvalidNamedCapture = "invalid named capture"
pkg regexp/syntax, const ErrInvalidPerlOp = "invalid or unsupported Perl syntax"