Error Recovery
A parser should be able to detect and report any error in the program. It is expected that when an error is encountered, the parser should be able to handle…
LR PARSERS
An efficient bottom-up syntax analysis technique that can be used CFG is called LR(k) parsing. The ‘L’ is for left-to-right scanning of the input, the ‘R’ for constructing a rightmost…
BOTTOM-UP PARSING
Constructing a parse tree for an input string beginning at the leaves and going towards the root is called bottom-up parsing. A general type of bottom-up parser is a shift-reduce…
TOP-DOWN PARSING
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…
WRITING A GRAMMAR
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,…
Context-Free GRAMMARS
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.…
Error Handling in Compiler Design
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…
Types of Parsing
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 ROLE OF PARSER
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
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…
