SLR(1) Parser- Part (2)
The below is the graphical representation of the given productions
Step 2: Construction of SLR Parser table.
| Stack | Action | Goto | |||
| a | b | $ | S | A | |
| 0 | S3 | S4 | 1 | 2 | |
| 1 | Accept | ||||
| 2 | S3 | S4 | 5 | ||
| 3 | S3 | S4 | 6 | ||
| 4 | |||||
| 5 | R1 | ||||
| 6 | |||||
I1 : S’ → S •
I5 : S → AA •
I6 : A → aA •
I4 : A → b •
FIRST(S) = {a, b} FOLLOW = {$}
FIRST(A) = {a, b} FOLLOW = {a, b, $}
Step 3: Parsing of the input string
The given string is ‘aabb’
| STACK | I/P BUFFER | ACTION TABLE | GOTO TABLE | PARSING ACTION |
| $0 | aabb$ | [0,a]=S3 | Shift | |
| $0a3 | abb$ | [3,a]=S3 | Shift | |
| $0a3a3 | bb$ | [3,b]=S4 | Shift | |
| $0a3a3(b4) | b$ | [4,b]=r3 | [3,A]=6 | Reduce r3: A → b |
| $0a3a3A6 | b$ | [6,b]=r2 | [3,A]=6 | Reduce A → aA |
| $(0a3A6) | b$ | [6,b]=r2 | [0,A]=2 | Reduce A → aA |
| $0A2 | b$ | [2,b]=s4 | Shift | |
| $0A2b4 | $ | [4,$]=r3 | [2,A]=5 | Reduce A → b |
| $0(A2b5) | $ | [5,$]=r1 | [0,5]=1 | Reduce A → A • A |
| $0S1 | $ | [1,$]=accept |
Construction of SLR Parser
| Stack | Action | Goto | |||||||
| id | + | * | ( | ) | $ | E | T | F | |
| 0 | S5 | S4 | 1 | 2 | 3 | ||||
| 1 | S6 | ||||||||
| 2 | S7 | ||||||||
| 3 | |||||||||
| 4 | S5 | S4 | 8 | 2 | 3 | ||||
| 5 | 9 | 3 | |||||||
| 6 | S5 | S4 | |||||||
| 7 | S5 | S4 | 10 | ||||||
| 8 | S6 | S11 | |||||||
| 9 | S7 | ||||||||
| 10 | |||||||||
| 11 | |||||||||
Reference Link