Compilers Lecture 5: Syntax Analysis

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What is the primary function of a parser in the syntax analysis phase?

To verify that the tokens generated by the lexical analyzer are grouped according to the syntax rules of the language (correct)
To perform semantic analysis on the source program
To construct the parse tree from the grammar rules
To generate intermediate code from the source language

What is the purpose of a parse tree in syntax analysis?

To perform lexical analysis on the source program
To represent the syntactic structure of program statements (correct)
To generate intermediate code from the source language
To detect and report semantic errors

What is the name of the popular format used to write Context-Free Grammars (CFGs)?

Syntax Tree Notation
EBNF (Extended Backus-Naur Form)
CFG (Context-Free Grammar)
BNF (Backus-Naur Form) (correct)

What is the role of the '→' symbol in BNF grammar rules?

Indicating productions (B) Signup and view all the answers

What is the implication of the indentation of the else-part in the given code?

An else-part should always be associated with the nearest if-statement that does not yet have an associated else-part (B) Signup and view all the answers

What is the purpose of using brackets { } in C to resolve the dangling else problem?

To force all else-parts to be matched as soon as possible (D) Signup and view all the answers

What is the result of parsing a string that does not conform to the grammar rules of the language?

The parser detects and reports a syntax error (A) Signup and view all the answers

What is the main difference between leftmost and rightmost derivation?

In leftmost derivation, the leftmost non-terminal is replaced at each step, whereas in rightmost derivation, the rightmost non-terminal is replaced at each step. (B) Signup and view all the answers

What is the start symbol in the given BNF grammar rules?

exp (D) Signup and view all the answers

What is the characteristic of a matched statement in the context of the dangling else problem?

It is an if-else statement containing no open statements, or it is any other kind of unconditional statement (C) Signup and view all the answers

What is the purpose of a parse tree?

To summarize the derivation of a sentence without specifying the order in which rules were applied (D) Signup and view all the answers

What is the main characteristic of an abstract syntax tree (AST)?

It is a condensed form of a parse tree with operators at internal nodes (B) Signup and view all the answers

What is the dangling else problem in the context of parser design?

A situation where an else-part can be associated with multiple if-statements (C) Signup and view all the answers

What is the term for a grammar that can produce more than one parse tree for a given sentence?

Ambiguous grammar (A) Signup and view all the answers

What is the purpose of the parse tree for the unambiguous grammar in the context of the dangling else problem?

To illustrate the most closely nested rule for the dangling else problem (A) Signup and view all the answers

What is the role of the parser in handling the dangling else problem?

To use the most closely nested rule to resolve the ambiguity (B) Signup and view all the answers

What is the main purpose of a parser design?

To analyze the syntax of a sentence and produce a parse tree (D) Signup and view all the answers

What is the term for a situation where a grammar can produce more than one possible parse tree for a given sentence?

Ambiguous grammar (B) Signup and view all the answers