Basic Computer Science

When we encounter declarations, we need to lay out storage for the declared variables. For every local name in a procedure, we create a ST(Symbol Table) entry containing: The type…

YACC stands for Yet Another Compiler Compiler. YACC provides a tool to produce a parser for a given grammar. YACC is a program designed to compile a LALR (1) grammar. It…

LALR refers to the lookahead LR. To construct the LALR (1) parsing table, we use the canonical collection of LR (1) items. In the LALR (1) parsing, the LR (1)…

When you create a parse tree then it contains more details than actually needed. So, it is very difficult to compiler to parse the parse tree. Take the following parse…

Three-address code is a sequence of statements of the general form x : = y op z where x, y and z are names, constants, or compiler-generated temporaries; op stands…

A source code can directly be translated into its target machine code, then why at all we need to translate the source code into an intermediate code which is then…

To perform SLR parsing, take grammar as input and do the following: 1.   Find LR(0) items. 2.  Completing the closure. 3.  Compute goto(I,X), where, I is set of items and X is grammar…

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…

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…

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…