func NewLexerString(s string, posix, whitespacesplit bool) *Lexer {
	return NewLexer(strings.NewReader(s), posix, whitespacesplit)
}
func NewLexerString(s string, posix, whitespacesplit bool) *Lexer {
	return NewLexer(strings.NewReader(s), posix, whitespacesplit)
}
// NewLexerString creates a new Lexer reading from a string.  This
// Lexer has a DefaultTokenizer according to posix and whitespacesplit
// rules.