Example for LALR (1) Parser
Let us take an example for LALR(1) Parser and understand it better
Example:
Consider the grammar S → AA
A → aA/b
And construct LALR (1) parser
Sol: 1. Construction of a canonical set of items
→ Construct augmented grammar as:-
S1 → S
S → AA
A → aA/b
I : S1 → .S
Closure (I) = S1 → .S, $
S → .AA, $
A → .aA, a/b
A → .b, a/b
Goto (I0, $) = I1
S1 → S., $
Goto (I0, A) = I2
S → A•A, $
A → •aA,$
A → •b, $
Goto (I0, a) = I3
A → A•A, a/b
A → •aA, a/b
A → •b, a/b
Goto (I3, b) = I4
A → b•, a/b
Goto (I0, b) = I4
A → b•, a/b
Goto (I4, A) = I5
S → AA• $
Goto (I2, a) = I6
S → A•A, $
A → •aA,$
A → •b, $
Goto (I0, A) = I6
S → A•A, $
A → •aA,$
A → •b, $
Goto (I0, A) = I2
S → A•A, $
A → •aA,$
A → •b, $
Goto (I2, b) = I7
A → b, $
Goto (I0, b) = I7
A → b•, $
Goto (I0, b) = I4
A → b•, a/b
Goto (I3, A) = I8
A → aA•, a/b
Goto (I3, a) = I3
S → A•A, a/b
A → •A,a/b
A → •b, a/b
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