GLOSSARY
Accumulator is a special register in the processor which takes part in almost all arithmetic and logical operations.
Acyclic graph is a graph without a cycle, i.e. a path from a vertex back to itself, possibly via a number of other vertices.
Alphanumeric characters are drawn from a set of alphabetic and numeric characters.
Backus-Naur Form See BNF
BNF is a notation for context-free grammars, often used to describe the syntax of computer programming languages, document formats, instruction sets and communication protocols. Extended Backus-Naur Form (EBNF) is extension of the basic Backus-Naur Form (BNF).
CRT – Cathode Ray Tube An older technology for graphical displays such as TV and computer video Terminals.
DAG Directed Acyclic Graph
Descending is decreasing order of some key elements in the data.
Devanagari script is used for writing several Indian languages like Sanskrit, Marathi, Hindi and also Nepali.
Encode Allocates a code to a set of data elements.
Expression is a valid arrangement of variables, constants, operators and factions.
Hexadecimal base 16 positional number system.
Indexed addressing involves adding, possibly a multiple of, an integer index value to a base address, generally used for accessing an array.
Initialize Prepare the initial state of a program's variables, data structures, etc.
Interpret a statement means finding out what action the statement implies and execute that action.
Keywords have some specific semantic significance or meaning in the source language. Keywords are usually also reserved words.
Machine-dependent optimization methods try to make the target code corresponding to the source program more efficient and less resource hungry, using the techniques utilizing particular characteristics and facilities of the architecture of the processor.
Machine-independent optimization methods try to make the target code corresponding to the source program more efficient and less resource hungry, using the techniques independent of the architecture of the processor.
Mapper is another name for semantic analyzer. It converts or maps the parse tree into an Intermediate Representation.
Meta-literal is a symbol which belongs to a meta-language and stands for a particular construct in the object language.
Meta-variable a symbol which belongs to a meta-language and stands for elements of some object language. For example, in the sentence “Let S1 and S2 be two sentences of a language L” the symbols S1 and S2 are part of the meta-language in which the statement about the object language L is written.
Optimize is the process of modifying a program to make some aspect of it work more efficiently or use fewer resources.
Parser is another name for the syntax analyzer, which identifies language elements like variables, numbers, keywords and builds the parse tree.
Parse tree is a representation of a statement of the source program in the form of a tree, showing syntactical relationships between various tokens in the statement.
Pedagogic is related to teaching or training.
POSIX – “Portable Operating System Interface for Unix” A family of related standards specified by the IEEE to define the application programming interface (API), along with shell and utility interfaces for software compatible with variants of the Unix operating system, although the standard can apply to any operating system.
Reserved words are words or identifiers reserved for special use by the language grammar. They must not be used as user variables in the source program.
Right-iterative form of a grammar contains production rules in which the RHS is in the form of iteration or repetition of some part of the string on the right-hand end. For example, A → B {C}, where the braces indicate indefinite numbers of times that C can be added.
Right-recursive form of a grammar contains production rules in which the RHS is in the form of recursion on the right-hand end. For example, A → B A.
Scanner is another name for a lexical analyzer. It breaks down source programs into the language atoms, creates their internal representations and prepares a Symbol Table.
Simulator is a software which mimics the actions of a hardware which is not available, not present or not being used.
Threads of control flow are allowed by most modern operating systems, allowing multiple streams of code being executed on the processor.
Two-address instructions contain at most two memory references.
Unsigned-number is a number without the sign information, always considered to be of positive value.
White spaces are characters which are not seen in a display or printout, especially space, tab and new-line. A compiler considers comments also as white-spaces.