An LALR(1) parser for a grammar G can have shift-reduce (S-R) conflicts if and only if

Related MCQs

• Consider the following expression grammar. The seman-tic rules for expression calculation are stated next to each grammar production. E → number E.val = number. val | E '+' E E(1).val = E(2).val + E(3).val | E '×' E E(1).val = E(2).val × E(3).val The above grammar and the semantic rules are fed to a yacc tool (which is an LALR (1) parser generator) for parsing and evaluating arithmetic expressions. Which one of the following is true about the action of yacc for the given grammar?
• Assume that the SLR parser for a grammar G has n1 states and the LALR parser for G has n2 states. The relationship between n1 and n2 is:
• Consider the following grammar: S → FR R → S | ε F → id In the predictive parser table, M, of the grammar the entries M[S, id] and M[R, $] respectively.
• Consider the following two sets of LR(1) items of an LR(1) grammar. X -> c.X, c/d X -> .cX, c/d X -> .d, c/d X -> c.X, $ X -> .cX, $ X -> .d, $ Which of the following statements related to merging of the two sets in the corresponding LALR parser is/are FALSE? 1. Cannot be merged since look aheads are different. 2. Can be merged but will result in S-R conflict. 3. Can be merged but will result in R-R conflict. 4. Cannot be merged since goto on c will lead to two different sets.
• Consider the following grammar. S -> S * E S -> E E -> F + E E -> F F -> id Consider the following LR(0) items corresponding to the grammar above. (i) S -> S * .E (ii) E -> F. + E (iii) E -> F + .E Given the items above, which two of them will appear in the same set in the canonical sets-of-items for the grammar?
• Consider the grammar S → (S) | a Let the number of states in SLR(1), LR(1) and LALR(1) parsers for the grammar be n1, n2 and n3 respectively. The following relationship holds good
• Which of the following grammar rules violate the requirements of an operator grammar ? P, Q, R are nonterminals, and r, s, t are terminals. 1. P → Q R 2. P → Q s R 3. P → ε 4. P → Q t R r
• Consider the grammar shown below S → i E t S S' | a S' → e S | ε E → b In the predictive parse table. M, of this grammar, the entries M[S', e] and M[S', $] respectively are
• Consider the following two statements: P: Every regular grammar is LL(1) Q: Every regular set has a LR(1) grammar Which of the following is TRUE?
• The grammar A → AA | (A) | ε is not suitable for predictive-parsing because the grammar is