Factor      = production_name | token [ "…" token ] | Group | Option | Repetition .
Group       = "(" Expression ")" .
Option      = "[" Expression "]" .
Repetition  = "{" Expression "}" .
</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)

bits, a reseed interval of 2^48 requests, and a // maximum request size of 2^19 bits (2^16 bytes, 64 KiB). // // We support a narrow range of parameters that fit the needs of our RNG: // AES-256, no derivation function, no personalization string, no prediction // resistance, and 384-bit additional input. type Counter struct { // c is instantiated with K as the key and V as the counter. c aes.CTR reseedCounter uint64 } const ( keySize = 256 / 8 SeedSize = keySize + aes.BlockSize reseedInterval = 1 << 48...