1. Lex keywords as identifiers. Compute simple hashsum while recognizing (acc = acc * N + x).
2. Make pass over tokens to resolve hashes
	consult ehash = EXACT_HASH[(hash >> (i * P)) & ((1 << P) - 1)] for i in 0..Q
		if ehash.key matches your hash, record ehash.value as the hash instead
		otherwise, record 0

	N, P and Q make PHF
	N is choosen to minimize P and Q,
	P is the size of the EXACT_HASH table
	Q is the max collision size (usually 2)

3. When new token begins:
	3.a) add TOK[REC] to the retired token's value
	3.b) set REC to REC_HASH[hash].
4. If CHECK[REC] == current character, advance to REC+1,
	otherwise, set REC=BADREC

Generation:
	TOK[X] = 0 if X does not recognize a keyword
	TOK[X] = TOKEN(Keyword) - TOKEN(Identifier) if X recognizes a keyword

	REC_HASH[hash(X)] = X

	CHECK[X + 0], CHECK[x + 1] etc equal to characters 0, 1, ... in X keyword