The lexical analysis for a modern computer language such as Java needs the power of which one of the following machine models in a necessary and sufficient sense?

Related MCQs

• Consider the following statements related to compiler construction : I. Lexical Analysis is specified by context-free grammars and implemented by pushdown automata. II. Syntax Analysis is specified by regular expressions and implemented by finite-state machine. Which of the above statement(s) is/are correct?
• Match all items in Group 1 with correct options from those given in Group 2. List I List II P. Regular Expression 1. Syntax analysis Q. Push down automata 2. Code Generation R. Dataflow analysis 3. Lexical analysis S. Register allocation 4. Code optimization
• A lexical analyzer uses the following patterns to recognize three tokens T1, T2, and T3 over the alphabet {a,b,c}. T1: a?(b∣c)*a T2: b?(a∣c)*b T3: c?(b∣a)*c Note that ‘x?’ means 0 or 1 occurrence of the symbol x. Note also that the analyzer outputs the token that matches the longest possible prefix. If the string bbaacabc is processes by the analyzer, which one of the following is the sequence of tokens it outputs?
• Let L1 be a regular language, L2 be a deterministic context-free language and L3 a recursively enumerable, but not recursive, language. Which one of the following statements is false?
• Consider the following statements: (I) The output of a lexical analyzer is groups of characters. (II) Total number of tokens in printf("i=%d, &i=%x", i, &i); are 11. (III) Symbol table can be implementation by using array and hash table but not tree. Which of the following statement(s) is/are correct?
• Which of the following problems are decidable? 1) Does a given program ever produce an output? 2) If L is a context-free language, then is L’ (complement of L) also context-free? 3) If L is a regular language, then is L’ also regular? 4) If L is a recursive language, then, is L’ also recursive?
• Which of the following are decidable ? 1. whether the intersection of two regular language is infinite. 2. whether a give context free language is regular 3. whether two push down automata accept the same language. 4. whether a given grammar is context free
• Consider the set of strings on {0,1} in which, every substring of 3 symbols has at most two zeros. For examples, 001110 and 011001 are in the language, but 100010 is not. All strings of length less than 3 are also in the language. A partially completed DFA that accepts this language is shown below. The missing arcs in the DFA are
• Let L1 be a recursive language, and let L2 be a recursively enumerable but not a recursive language. Which one of the following is TRUE?
• Consider the following two statements: S1: { 0^2n |n >= l} is a regu1ar language S2: { 0^m 0^n 0^(m+n) l m >= 1 and n >= 2} is a regu1ar language Which of the following statements is correct?