LL1 Parsing a b $ S 1 A 4 B 3 2 - - PowerPoint PPT Presentation

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May 13, 2023 513 likes •694 views

LL1 Parsing a b $ S 1 A 4 B 3 2 a b b b 1. S --> a B Input 2. B --> 3. B --> A S 4. A --> b B Parse Stack Compare Input and Stacktop 1 LL1 Parsing a b $ S 1 A

SLIDE 1

LL1 Parsing

Parse Stack

S a b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

Compare Input and Stacktop

1

SLIDE 2

LL1 Parsing

Parse Stack

S a b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

Get Predicted Production

2

SLIDE 3

LL1 Parsing

Parse Stack

S a b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

Replace Top with RHS

3

SLIDE 4

LL1 Parsing

Parse Stack

a b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

a B

New Stack Contents

4

SLIDE 5

LL1 Parsing

Parse Stack

a b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

a B

Discard Matching Tokens

5

SLIDE 6

LL1 Parsing

Parse Stack

b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

B

Compare Input and Stacktop

6

SLIDE 7

LL1 Parsing

Parse Stack

b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

A

Compare Input and Stacktop

7

SLIDE 8

LL1 Parsing

Parse Stack

b b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

b B

Discard Matching Tokens

8

SLIDE 9

LL1 Parsing

Parse Stack

b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

B

Compare Input and Stacktop

9

SLIDE 10

LL1 Parsing

Parse Stack

b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

A

Compare Input and Stacktop

10

SLIDE 11

LL1 Parsing

Parse Stack

b b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

b B

Discard Matching Tokens

11

SLIDE 12

LL1 Parsing

Parse Stack

b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

B

Compare Input and Stacktop

12

SLIDE 13

LL1 Parsing

Parse Stack

b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

A

Compare Input and Stacktop

13

SLIDE 14

LL1 Parsing

Parse Stack

b

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

b B

Discard Matching Tokens

14

SLIDE 15

LL1 Parsing

Parse Stack

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

B

Compare Input and Stacktop

15

SLIDE 16

LL1 Parsing

Parse Stack

1. S --> a B
2. B --> “”
3. B --> A
4. A --> b B

a b $ S 1 A 4 B 3 2

Input

DONE

16

SLIDE 17