Test by Bikram | Mock GATE | Test 1 | Question: 13

Question

Match the following:

List I		List II
A	Backus Naur form	1	Regular expression
B	Lex	2	$\left ( I \right )$$LALR$
C	Yacc	3	$LL$$\left ( 1 \right )$
D	Recursive descent parsing	4	$CFG's$

 $$\begin{array}{|c|c|c|} \hline & \textbf{List I} &  &\textbf{List II} \\ \hline A & \text{Backus Naur form} & 1 & \text{Regular expression} \\ \hline B & \text{Lex} & 2 & (I) LALR \\ \hline C & \text{Yacc} & 3 & LL(1) \\ \hline D & \text{Recursive descent parsing } & 4 & \text{CFG’s}  \\ \hline\end{array}$$

• A. $A-2; \: B-1; \: C-3; \: D-4;$
• B. $A-4 ; \: B-3 \: ; C- 1 \: ; D-2;$
• C. $A-4; \: B-1 \: ; C-2; \: D-3;$
• D. $A-1; \: B-4; \:C-2; \: D-3;$

Answer 1

A) Backus Naur Form (BNF) is another way of representing the things that are shown in the Context Free Grammar (CFG).

B) Lex, officially known as a "Lexical Analyser", is used to identify single character terminals in a text file. Like #, {, semicolon, dot.

C) YACC stands for "Yet Another Compiler Compiler". YACC is a bottom-up parser.

D) Recursive descent parser is a top-down parser, hence LL(1).

Therefore answer is C.

Comments

As far as I know LL(1) parser is Non-recursive descent parser and it is Top down parser without backtracking.