Arrange the following parsers in increasing order of their power of handling grammars i.e. from the least powerful parser to the most powerful parser.
A. LR(0)
B. LR(1)
C. LALR(1)
D. LL(0)
E. SLR
Choose the correct answer from the options given below:
1.LL(0)→LR(0) SLRLR(1)→LALR(1)
2.SLR LR(0) LL(0)→LR(1) LALR(1)
3.LL(0) → LR(0) → SLR(1) → LALR(1) → LR(1) ✓ Correct
4.LR(0) LL(0)→SLRLR(1)→LALR(1)
Solution
The correct answer is: Option 3
Key Points
- Parsers are used to analyze the structure of a given input based on a set of grammatical rules.
- The question asks to arrange the given parsers in increasing order of their power of handling grammars.
- The power of a parser depends on the type of grammars it can handle, with more powerful parsers capable of handling a broader set of grammars.
Explanation
Let us examine each parser:
- LL(0): LL(0) parsers are the least powerful. They can handle only a limited set of grammars (left-to-right parsing and no lookahead).
- LR(0): LR(0) parsers are more powerful than LL(0) parsers, as they can handle a larger set of grammars. They perform bottom-up parsing.
- SLR: SLR (Simple LR) parsers are an improvement over LR(0) parsers, as they use follow sets to resolve conflicts.
- LALR(1): LALR(1) parsers (Look-Ahead LR) further extend SLR parsers, handling an even larger set of grammars.
- LR(1): LR(1) parsers are the most powerful among the given parsers, as they use one token lookahead and can handle the largest set of grammars.
Final Order
Arranging the parsers in increasing order of their power:
LL(0) → LR(0) → SLR → LALR(1) → LR(1)
Correct Answer
The correct answer is: Option 3
