Basic Computer Science

It can be viewed as an attempt to find a left-most derivation for an input string or an attempt to construct a parse tree for the input starting from the…

A grammar consists of a number of productions. Each production has an abstract symbol called a nonterminal as its left-hand side, and a sequence of one or more nonterminal and terminal symbols as its right-hand side. For each grammar,…

A Context-Free Grammar is a quadruple that consists of terminals,non-terminals, start symbol and productions.   Terminals: These are the basic symbols from which strings are formed. Non-Terminals: These are the syntactic variables that denote a set of strings.…

The tasks of the Error Handling process are to detect each error, report it to the user, and then make some recover strategy and implement them to handle error. During this whole…

Syntax analyzers follow production rules defined by means of context-free grammar. The way the production rules are implemented (derivation) divides parsing into two types : top-down parsing and bottom-up parsing.…

The parser or syntactic analyzer obtains a string of tokens from the lexical analyzer and verifies that the string can be generated by the grammar for the source language. It…

Syntax analysis or parsing is the second phase of a compiler. In this chapter, we shall learn the basic concepts used in the construction of a parser. We have seen…

DFA minimization stands for converting a given DFA to its equivalent DFA with minimum number of states. Minimization of DFASuppose there is a DFA D < Q, Σ, q0, δ,…

The lexical analyzer needs to scan and identify only a finite set of valid string/token/lexeme that belong to the language in hand. It searches for the pattern defined by the…

Finite automata is a state machine that takes a string of symbols as input and changes its state accordingly. Finite automata is a recognizer for regular expressions. When a regular…