(Attribute values are only relevant for attribute evaluation discussed in Section 9.2.) Compute-closure is a parameter so that the parser is sufficiently general to also perform SLR or LALR
parsing; Section 9.1 provides details.
Yacc 7432 An implementation of an LALR
 uses default reductions in addition to LALR
Lossy compression of the terminal reduction actions and the invalid reductions permitted by other parser classes (LALR(1), SLR(1)) limit validation to shifts of non-[Epsilon]-subtrees.(15) However, if an LALR
or SLR parser generator identifies reductions guaranteed never to be erroneous, reduction validation can be employed on a case-by-case basis.
Because a program's syntax is typically defined with an LL, LALR
, or LR grammar, the parsing phase can always be carried out in linear time.