LR(0) Parser


R means rightmost derivation in reverse
Task in LR parsing: determining the handle, thus the next RSF

LR(0) means no need to look ahead to determine the handle

Item: a state representing the status of RHS recognition
- use a dot “.” to separate the recognized part and the rest

## item
a state representing the status of RHS recognition
### initial items



### complete items
handle candidates



Action: shift or reduce (using which rule) based on state


table header is
- State
- Action
> - shift
> - accept
> - reduce
- Rule if action is reduce


### LR(0) Conflicts
Action (shift/reduce) at a state is unclear
- Shift-reduce conflict : one item can shift, another can reduce
- Reduce-reduce conflict : two (or more) items that can reduce
If no state has conflicts, the grammar is LR(0) grammar






