Java Reference
In-Depth Information
function
C
losure
(
state
)
returns
Set
ans
←
state
repeat
prev
←
ans
14
foreach
A
→α•
B
γ∈
ans
do
15
foreach
p
∈
P
roductions
F
or
(
B
)
do
ans
←
ans
∪{
B
→•
RHS(
p
)
}
16
until
ans
=
prev
return
(
ans
)
end
procedure
C
ompute
G
oto
(
States
,
s
)
closed
←
C
losure
(
s
)
17
foreach
X∈
(
N
∪Σ
)
do
18
RelevantItems
←
A
dvance
D
ot
(
closed
,X
)
19
if
RelevantItems
∅
then
Table
[
s
][
X
]
←
shift A
dd
S
tate
(
States
,
RelevantItems
)
20
end
Figure 6.10: LR(0) closure and transitions.
State 0
Goto
State 3
Goto
State 4
Goto
$
E
Start
→•
E $
3
Start
→
E
•
$
4
Start
→
E $
•
E
→•
plus E E
1
E
→•
num
2
num
plus
num
State 1
Goto
State 2
Goto
E
→
plus
•
EE
5
E
→
num
•
plus
E→• plus E E
1
E→• num
2
num
plus
E
E
State 5
Goto
State 6
Goto
E→plus E • E
6
E→plus E E •
E
→•
plus E E
1
E
→•
num
2
Figure 6.11: LR(0) computation for Figure 6.2, shown as a
characteristic finite-state machine. State 0 is the initial state,
and the double-boxed states are accept states.
