CSCE 434 Lecture 20

« previous | Wednesday, October 9, 2013 | next »

Lecture Slides

Building a SLR parser

Canonical LR(0) items

Kernel items: all items with cursor at left end of RHS, with addition of a rule $\left[S'::=\cdot S\right]$.

$S'::=S$ is a production in the augmented grammar $G'$ mapping a new start state $S'$ to the start state of a grammar $G$.

We do this because we cannot have an "initial" item $\cdot S$ or final item $S\cdot$ in the original grammar (nothing goes to $S$)

$I$: set of items; take its closure (all possible items reachable from the current state)