Computer Science Engineering (CSE) Exam > Computer Science Engineering (CSE) Questions > Which of the following derivations does a top...
Start Learning for Free
Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right order
- a)Left most derivation
- b)Left most derivation traced out in reverse
- c)Right most derivation
- d)Right most derivation traced out in reverse
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
Which of the following derivations does a top- down parser use while p...
Top down parser uses left to right, left most derivation.
Most Upvoted Answer
Which of the following derivations does a top- down parser use while p...
Understanding Top-Down Parsing
Top-down parsing is a strategy used in syntax analysis where the parser begins with the start symbol and works its way down to the input string.
Left Most Derivation
- A left most derivation is a sequence of production rule applications that always replaces the leftmost non-terminal at each step.
- For example, if we have a grammar and an input string, the parser will replace the leftmost non-terminal in the current string until it derives the input string.
Why Option A is Correct
- Top-down parsers, such as Recursive Descent and LL parsers, inherently follow the leftmost derivation.
- They make decisions based on the current non-terminal and the next input symbol, continuously replacing the leftmost non-terminal until the input is fully parsed.
- This approach allows top-down parsers to predict which production to use based on the current state of the input.
Comparison with Other Options
- Left most derivation traced out in reverse (Option B): This option suggests a backward approach, which is not how top-down parsers operate.
- Right most derivation (Option C): Right most derivation focuses on replacing the rightmost non-terminal, which is characteristic of bottom-up parsers.
- Right most derivation traced out in reverse (Option D): Similar to option C, but in reverse, which again does not align with the principles of top-down parsing.
Conclusion
In summary, top-down parsers utilize leftmost derivation to construct the parse tree from the top down, making option A the correct choice in this context. Understanding this fundamental aspect is crucial for grasping parsing techniques in compiler design.
Top-down parsing is a strategy used in syntax analysis where the parser begins with the start symbol and works its way down to the input string.
Left Most Derivation
- A left most derivation is a sequence of production rule applications that always replaces the leftmost non-terminal at each step.
- For example, if we have a grammar and an input string, the parser will replace the leftmost non-terminal in the current string until it derives the input string.
Why Option A is Correct
- Top-down parsers, such as Recursive Descent and LL parsers, inherently follow the leftmost derivation.
- They make decisions based on the current non-terminal and the next input symbol, continuously replacing the leftmost non-terminal until the input is fully parsed.
- This approach allows top-down parsers to predict which production to use based on the current state of the input.
Comparison with Other Options
- Left most derivation traced out in reverse (Option B): This option suggests a backward approach, which is not how top-down parsers operate.
- Right most derivation (Option C): Right most derivation focuses on replacing the rightmost non-terminal, which is characteristic of bottom-up parsers.
- Right most derivation traced out in reverse (Option D): Similar to option C, but in reverse, which again does not align with the principles of top-down parsing.
Conclusion
In summary, top-down parsers utilize leftmost derivation to construct the parse tree from the top down, making option A the correct choice in this context. Understanding this fundamental aspect is crucial for grasping parsing techniques in compiler design.
|
Explore Courses for Computer Science Engineering (CSE) exam
|
|
Top Courses for Computer Science Engineering (CSE)View all
Top Courses for Computer Science Engineering (CSE)
Question Description
Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? for Computer Science Engineering (CSE) 2025 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer?.
Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? for Computer Science Engineering (CSE) 2025 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer?.
Solutions for Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Computer Science Engineering (CSE).
Download more important topics, notes, lectures and mock test series for Computer Science Engineering (CSE) Exam by signing up for free.
Here you can find the meaning of Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Which of the following derivations does a top- down parser use while parsing as input string? The input is assumed to be scanned in left to right ordera)Left most derivationb)Left most derivation traced out in reversec)Right most derivationd)Right most derivation traced out in reverseCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Computer Science Engineering (CSE) tests.
|
|
Explore Courses for Computer Science Engineering (CSE) exam
|
|
Signup to solve all Doubts
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup on EduRev and stay on top of your study goals
10M+ students crushing their study goals daily