Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 1885-52-15 (1986): Electrotechnical vocabulary, Part 52:Data processing, Section 15: Programming languages [LITD14: Software and System Engineering]

Ildian Standard ,

ELE~ROTECHlitCAL VOCABULARY

PART 62 DATA PROCESSING

Section 15 Programming Languages

Basic Standards an Electronics and Telecommunication Sectional Committee, LTDC 1

* Chairman

PROPS. SAMPATH

Representfag

Indian Institute of Technology, Kaapur

Members . DR K. CHANDM SHRl %. A. CHl!TN DIRECTOR

National Physical Laboratory, New Delhi Department of Electronics, New Delhi Dspar+qt of S&We and Technoloof, New

Wlhi JO$~~;IREC$R STANDARDS Ministry of Railways ( RDSO ), Lucknow

Jornr DWOR STAND= -( s-e T )/T&u.8 ( &mw?t~ 1

SHIU 0. P. KIiusriu All III& Radio, New Delhi wo $ia 8.5. mpzAL YWahoif Dafence, DTD k P ( AIR ), New

---- tkJN ba K. Ni SAIIpATa KUMAS

Posts aad Telegraphs Department, New Delhi Institution of Electronics and Telecommunica.

tion Engineers, New Delhi MAJ GBN J. S. AHLUWACIA ( Alternate )-

SHRI B. S. RAO Ministry of Defence ( R & D ) SHRI P. C. NAGPAL ( Alternate )

, LT-GEN D. SWAROOP ’ Vice Chairman, Electronics and Telecom. municstion Division Council, IS1

SHRI N. SRINIVASAN, Director ( Electronics )

Director General, ISI ( Ex-oficio hfetnber )

( Secretary )

( Continued on page 2 )

@ Copyright 1987 INDIAN STANDARDS INSTITUTION

This publication is protected under the Indian Copyright Act (XIV of 1957 ) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act.

( ContinuedfiompWe 1 )

Computers, Business M&chines and Calculators Sectional Committee, LTDC 24

Chairman Representing

Dn N. SESILWIRI Department of Electronics, New Delhi

Members DR K. SUBIUMANIAN ( AIternatc tb

Shri N. Seshagiri ) SHRI R. P. AHUJA Computer Maintenance Corporation Ltd.

New Delhi SHRI C. K. BAPI~AJU SHRI S. K. BHATIA

State Bank of India,. Bombay Bharat Heavy Electrrcals Ltd, New Delhi

SHRI PVS CHELLAPATHI RAO ( Alternote ) DR VIJAY P. BHAIXAR Kerala State Electronics Development Car-

DR S. N. S. RAIE~EKRAN ( Alternate ) poration Ltd, Trivandrum

DR C. R. CHAKRAVARTHY Ministry of Defence SHRI K. N. DHEER b

R & D ) Indian Airlines, New elhi

SHRI HHWAR DUTr Electronics Trade and Technol % ment Corporation Ltd, New

Develop= lhi

SHRI DEEPAK GUPTA SHRI R. M. NAIR ( Altertwtc )

Tata Electric Companies, Bombay

Da A. LAHIRI Depart;;;t of Science and Technology, New

SHRI N. LAKSHMANAN Life Insurance Corporation of India, Bombay SHRI P. P. MALHOTRA Development Commissioner ( Small Scale

Industries ), New Delhi SHRI M. RAMAKRISHNAN ( Alternutc )

~Ac”~~ Hindustan Computers Ltd, New Delhi

SHRI ‘S. i. N. MURPHY Steel Authority of India Ltd, New Delhi Bharat Electronics Ltd, Bangalore

SHRI K. S. PBRINANAYAOM~ ( Alternate ). SERI 8. .K. P-BY Intcrn~trrl Computers Indian 1 Mfra Ltd,

SHRI Ii. Dnr ( Alternate ) SERI G. R~~OHUKUMAR The De.3e.gzih and General Mills Co Ltd,

SARI A. N. PAWAR ( Alternate ) I SHRIC. S. RAMCXANDMN Reserve Bank of India, Bombay

DR J. Gor%r.~ RAQ Blcctronics Corporation of India Ltd,

DR V. K. RA~~NDMN Hyderabad

PSI Data Systems Pvt Ltd, Bangalore ’ &-In1 V. L. &3EIPANDE(~k?rIIde)

PRO? R. SADANANDA SI-JRI K. L. GARO ( Alternate )

Computer Society of India, Bombay

Smu Aarrrs SEN Indian Statistical Institute, Calcutta Sriar UV~H P. SHAH ORG Systems, Vadodara

SHRI P. K. SRIDHARAN ( Afternote ) SHRI M. SHANKRAL~N~AM Directorate General of Supplies and Disposals,

New Delhi

( Continued on pugu I1 ) . .

2

Indian Standard *..

ELECTROTEtiHNICAL VOCABULARY

PART 52 DATA PROCESSING

Section 15 Programming Languages

0. FOREWORD

0.1 This Indian Standard ( Part 52/Set 15 ) was adopted by the Indian Standards Institution on 31 January 1986, after the draft finalized by the Basic Standards on Electronics and Telecommunication Sectional Committee, in consultation with Computers Business Machines and Calculators Sectional Committee had been approved by the Electronics and Telecommunications Division Council.

0.2 Electronic data processing is utilized for numerous exchanges and analysis of information of both intellectual and material nature. Application of electronic data processing becomes difficult, either because of-the great variety of terms used in various fields to express the same concept, orbecause of the absence of or the imprecision df useful coucepts. To overcome these barriers, this standard has been formulated.

0.3 This etaudard is ane of the series of Indian Standards on data processing vocabulary constituting Part 52 of the Electrotechnical Vocabulary.

0.4 Prime importance has been given to simplicity and clarity of the definitions so that it may be understood by all. It may, therefore, be felt that some definitions do not cover all the cases and exceptions.

0.5 Assistance has been derived in preparing this standard from Draft International Standard ISO/DIS 2382/l 5 ‘Data processing -Vocabulary - Part 15 Programming languages’ prepared by the International Orgy- nization for Standardization (HO).

1. SCOPE .

1.1 This standard (Part 52/Set 15) covers terms related to programming languages used with computers.

2. GENERAL-ORJRCTS

2.1 Lesicd Umitp+rriaril Token - A language construction that, by convention, represents an elemental unit of meaning.

a

J

18 : 1885 ( Part 52/Set 15 ) - 1986

Examples: A literal, such as ‘G25’; a keyword, such as PRINT; and a

separator, such as a semicolon.

2.2 Identifier - A lexical unit that names a language object.

Examples : The names of variables, arrays, records, etc. NOTE- An identifier usually consists of a letter optionally followed by letters,

digits or other characters.

2.3 Keyword - A lexical unit that, in certain context!, characterizes some language construction.

NOTE- A keyword normally has the form of an identifier.

2.4 Reserved Word - A keyword that may not be used as an identifier.

NOTE- In ADA all keywords are reserved words; FORTRAN has no,rcrervcd words.

23 Literal - A lexical unit that directly represents a value.

Examples: 14 represents the -integer fourteen, ‘APRIL’ represents the string

of character APRIL, 3.0005E2 represents the number 300.05.

2.6 Statement - A language construction that represents a set of declarations or a step in a sequence of actions.

NOTEI - In some programming languiges, for example. FORTRAN, a distinction is made between executablsaml non-executable statements.

Non32- In some programmi& laqquages, for example, PL/l, a distinction is made betwe~~~ de&rations and stateapcnts. I_

2.1 Compotmd Statement - A Hatement constructed by sequencing statemlntn.

Non- Most eften the statements are gtou& together by some syntactic deGce.

2.8 Block - A compound statement that coincides with the scope 9f at least one of the declarations contained within-it.

NOTE- A block’ may albo specify storage allocation or segment programs for other putpores.

a9 l&dale/Program Unit - A language construction that consists of procedures or data declarations and that can also interact with other such constructions.

Examples: In ADA a package; in FORTRAN, a program unit; in PL/l,

an external procedure.

4

IS : 1885 ( Part 52/Set 15 ) - 19g6

2.10 Encapsulated Type - A module representing an abstract data type. Example:

A stack processing module. NOTE - An encapsulated type hides the representation of its values but

permits operations on them by other modules.

2.11 Program - A logical assembly of one, or more than one, interrelated modules.

2.12 Comment - A language construction for the inclusion ’ of text in a program and having no impact on the execution of the program.

NOTE. - Comments are used to explain certain aspects of the program.

2.13 Environment Description - A language c’onsttuction for the description of features that are not part of a program but are relevant to its execution.

E;)(amples:

Machine characteristics, special prop&ties of files, interfaces w#ith: other programs.

3, GENERAL PROPERTIES AND MECHANISMS

3.1 Declaration - The mechanism for establishing a language object. N~TB - A declaration normally involves attaching an identifier, and allocating

attribrrtes, to the lantiage object concerned.

3.2 Defaolt - Pertaining to an attribute, value, or option that is assumed when none is explicity specified.

3.3 Implicit Declaration - A declaration, caused by the occurrence of an identifier and in which the attributes are determined by default.

3.4 Built-in/Predefined - Pertaining to a language object that is declared by the definition of the programming language.

Examples;

The build-in function SIN in PL/l, the predefined data type INTEGER in ADA.

3.5 Scope - That portion of a program within which the declaration applies.

NOTES- ‘The scope of an identifier’ is often used as a synonym for ‘the scope of its declaration’.

m?y% &dden by the declaration of the same identifier in an inner block. - A language object may not be referable throughout its scope since it

I$% : 1sgs ( Part ~Z/See 15 ) - l9g6

31 Local*- With respect to a block, qualifies a language object having a scope contained in that block.

3.7 Global - With respect to a block, qualifiesa language object having a .scope extending beyond that block but contained within an ehcompassing block.

3.8 External - Qualifies a language object having a scope errtending %yond one module.

! Example: The entry names of a module are external.

3.9 Static - Qualifies properties that can be established before the execution of a program.

Example: The length of a fixed-length variable is static.

3.10 Dynamic - Qualifies properties that can only be e&B&d during the execution of a program. .

Example: The length of a varying length data object is dynamic.

3.11 Lifetime - Of a language object, that portion of the execution time.during which the object exists.

3;12 Befcrrenee - A language construction, such as an identifier, designating a declared language object.

3:13 Qlul&8tioo - A mecbanis,m for referencing a component of a language object by means of a reference to the object and an identifier d8clMed for the component. ExampI& I Used for referencing record components ( B. of A in COBOL ),

members of a library, language objects .in a module. 3.14 Uniform Referencing - A property of a programming laagrrage such that two or more language. constructions for referencing are Of the same form. Examples:

Language constructions for name qualification and indirect refer- ences; language constructions for subscripting and actual parameters.

4. DATA OBJECTS 4.1 Variable - A language object that may take different values, one at time.

NOTE - The values of a variable are usually restricted to a certain data type. 6

IS : 1885 ( Part 52/Set 15 ) - 1986,

42 Constant - A language object that takes only oue specific value.. 4.3 Aggregate - A structured collection of variables or constants forming a data type. 4.4 Array - An aggregate that consists of data objects, with identical attributes, each of which may be uniquely referenced by subscripting. 4.5 Record - An aggregate consisting of data objects which usually have identifiers attached to them. 46 Variant Part - A part of a record whose data objects are defined in alternative ways.

NOTE - Both the number and composition of data objects can vary.

4.7 Ana ( ia a Programming Language ) - A space together with a mechanism for inserting data objects into it, and for accessing and for, deleting data objects from it.

4.8 Parameter/Dummy Argment - R liw~guage object,.~hoae identifkr appear in an entry of a procedure, that is associated with the corresponding actual parameter specified by the procedure call for every execution of the procedure.

4.9 Actual Parameter/Argument - A language object that appears in a procedure call and that is associated with the corresponding formal parameter for use in the execution of the procedure.

5. PR$‘& A@Jb MEcH;ApJI1stiS. RELATRD TO DATA

51 Type - A set of values> together with a set of permitted operations.

5.2 Picture - A language construction that describes a data type by means of a model character string literal.

5.3 Format - A language construction that specifies the representation, in character form, of data objects on a file.

5.4 Subscripting - A mechanism for referencing an array element by means of an array reference and one or more expressions that, when evaluated, denote the position of the element.

NOTE - This term also applies to the,use of the mechanism.

5.5 Indirect Referencing - A mechanism for referencing via a data object whose value points to the referenced language object.

NOTE 1 - This term also applies to the use of the mechanism.

NATE 2 - The referencing may be done along a chain of data objects in which each data object, except the last, points to the next, the last data object poiniing. to the ref$renced language object.

‘I]

IS : 1885 ( Part 52/Set IS ) - 1986

5.6 Data Flow - The transfer of data between constants, variab!es and files accomplished by the execution of statements, procedures, modules or programs.

5.7 Assignment - A mechanism to give a value to a variable or to an aggregate.

NOTE - This term also applies to the use of the mechanism.

5.8 Assignment by Name - An assignment of a record value to a record variable pertaining only to those components with the same identifier.

5.9 Iaitialize - To give a value to a data object at the beginning of its lifetime.

5.10 Automatic Storage Allocation - A mechanism for allocating space to data objects only for the duration of the execution &their scope.

NOTE - Autqnatic storage allocation is one form of dynamic stam allocation; another form ir program controlled storage allocation.

5.11 Assumed-Size Aggregate - An aggregate formal parameter that takes some or all of its subscript ranges from a corresponding actual parameter.

5.12 Ad&tables-Size Aggregate - An aggregate formal parameter with some or all of its subscript ranges dynamic.

5.13 Editing - Transforming values to the representations specified by a given format.

6. PROCESSING OBJECTS

6.1 Expression - A language construction for computing a value from one or more operands.

Non- calls, etc.

Operands may be literals, identifiers, array refereiws, fun&m

6.2 Procedure - A block, with or without parameters, whose execution is invoked by means of a procedure call.

6.3 Function - A procedure that, when executed, yields a value and whose procedure call may be used as an operand in an expression.

Examples :

The function SIN yields value SIN X when called part of the program.

8

6.4 Asynchronous Procedare - A procedure that can be executed concurrently with the calling part of the prograti. 6.5 Critical Section - In an asynchronous procedure, a part that cannot be executed simultaneously with a certain part of another asynchronous procedure.

NOTE - Tbst part of the other asynchronous procedure is also a critical section.

6.6 Label,, 1 A language construction naming a statement and including an identifier.

I 7. P-i dPERTIES AND MECHANISMS RELATED TO PROCESSING

/, 8JECTS C:i Execution Sequence - The order of the execution of statements and

,_” parts of statements of a program. 7.2 Control Flow - “+ An abstraction of all possible paths the execution

4 sequence may take through a program. NOTE - The control flow can ‘be represented by a control flow graph.

7.3 Unconditional Statement - A statement specifying only one possible execution sequence. 7.4 Conditional Construction - A language construction specifying several different execution sequences.

Examples: A CASE statement, an IF statement, a tionditional expression in

ALCiOL. 7.5 Loop Constmctioa - A language construction that specifies an iteration in the execution sequence.

Examples; FORTRAN DO, ALGOLFOR, COBOL PERFORM, PL/l DO

WHILE. 7.6 Call - A language construction for invoking the execution of a procedure.

NOTE - A procedure call usually includes an entry name and possible actual parameters.

7.7 Entry - A language construction within a procedure, designating a start of the execution sequences of the procedure.

NOTE -A procedure may have more than one entry; each entry usually includes an identifier! called the entry name and possible formal parameters.

7.8 Parameter Assaciation - The association of formal parameters with the corresponding actual parameters that are specified by a procedure call.

9

iS : 1885 ( Prrt52/Sec 15 ) - 1986

7.9 Return - A language construction within a procedure designating an end of the execution sequences in the procedure.

NOTE - Usually the execution sequence continues from the calling point.

7.10 Side Effect - Any external effect caused by k

execution of a function procedure other than that of yielding the result lue.

7.11 Branch Coaatruction - A language construction spec between Uifferent execution sequences by means of label r

7.12 Exception - A special situation which may arise duri which is considered abnormal, which may cause a deviat normal execution sequence and for which facilities programming language to define, raise, recognize, ignore and handle A

Examples: 2

(ON-) condition in PL/l, exception in ADA. \

7.13 Precedence - A rule for the order of the application of operators i \ within an expression.

7.14 Conversion - The transformation between values which represent the same datum but belong to different data types.

‘NOTE - Information may be lost due to conversion since accuracy of data representation varies among different data types.

7.15 Activation - The representation of a procedure created by the * invocation of that ,procedure.

7.16 Connection - A mechanism that enables interaction among modules, particularly procedure calls to asynchronous procedures.

Examples: In FCtRTRAM 3les ,are connected to mod&a.

10

( Continuedfrom page 2 )

Members Representing

SHRI V. R. UNNIRAMAN Tcleco~;tmication Research Centre, New

SARI K. M. VI~WANATI~AN Hindustan Teleprinters Ltd, Madras SHR~ S. DEVARAJAN (Alternate )

SBRI N. SRINIVISAN. Director General, IS1 ( Ex-o$&50 Member ) Director ( Electronics )

Secretary SHRI A. S. RAWAT

Deputy Director ( Electronics ), IS1

Programming Languages Subcommittee, LTCD 24 : 2

Convener

DR R. SADANANDA Members

SHRI A. M. ARORA

DR C. R. CHAKRAVARTHY SHRI E. THOMAN ( Alternote )

SHRI T. ESWAR

PROP D. V. Jo0

Jawaharlal Nehru University, New Delhi

Indian National . Scientific PoCUmCntdiOB Centre. New Delhi

Mini&y of Defenco ( DRDO )

Electronics Corporation of India Ltd, Hyderabad

Rrdian Institute of Technology, Bombay Police Computer Centrs. Bangalore

_Softek Pvt Ltd, New Delhi SHRI HEMAIW KUMAR ( Alternure 1

SHRI V. K. RAVINDRAN PSI Data Systems Pvt Ltd. Bangalore SHRI P. SADANANDAN National Centre for Software Development

and Computing Techniques. Bombay SHRI S. K. SINGHAL Tata Consultancy Services, Bombay DR R. VASUDEVAN Defence Research and Development Orgauim-

tion, New Delhi

11

Is : 1885 ( SIvt St/See 15 ) - MS6

INDEX

This index has been prepared in accordance with IS : 1275-1976+. Index numbers are clause numbers.

A

Activation 7.15 Actual parameter 4.9 Adjustable-size aggregate 5.12 Aggregate 4.3

Adjustable-size 5.12 Assumed-size 5. I 1

~~~;i$on, Automatic storage 5.10

Arguguz; 44’:

Array 4.4 ’ Assigomeat 5.7

by namo 5.9 Association, Parameter 7.8 A!mumt&sb amrogatet 5.M. Asynchronous procedun 4.4 Automatic storage&ocWon 5.10

B

Block 2.8 Branch c&structhm 7.11 Built-in 3.4

C Global 3.7

Call 7.6 Comment 2.12 Compound statement 2.7 Conditional construction 7.4 Connection 7.16 Constant 4.2 Construction 7.11

Branch 7.11 Conditional 7.4 LOOP 7.5

Control flow 7.2 Conversion 7.14 Critical section 6.5

I

ldontifier 2.2 Implicit declaration 3.3 Indirect referencing 54 Initialize 5.9

K

Keyword 2.3

L

D

Data flow 5.6 type 5.1

Declaration 3.1 Implicit 3.3

Default 3.2

Label 6.6 Lexical

unit 2.1 token 2.1

Lifetime 3.11 F;l;;;$5

Loop construction 7.5

Description, Environment 2.13 dummy argument 4.8

Dynamic 3.10

E

Editing 5.13 Effect, Side 7.10 Encapsuiated type 2.10

z%%ent description 2.13 Exce&t;“12

Bl&ess&.l .

i p, :-

.i

lw. contfof 7.2

‘.Dttta 5.6 Format 5.3 Rmction 6.3

G

*Rules for making alphabetical indexes ( firsr revision ).

12

M

Module 2.9

N

Name assignment by 5.8

P

,

Parameter 4.8 Actual 4.9 Association 7.8

Part 4.6 variant 4.6

Picture 5.2 Precedence 7.13 Predefined 3.4 Procedure 6.2

Asynchronous 6.4 Prog;;;:. 11

Q

Qualiecation 3.13

R Record 4.5 Reference 3.12 Referencing

Jndirect 5.5 Uniform 3.14

RetLe;Spgword . 2.4

S

Section, critical $5 gru;> execution 7.1

Side effect 7.10 Statement 2.7

Compound 2.6 Unconditional 7.3

Static 3.9 Storage allocation, Automatic 5.10 Subscripting 5.4

T

gzj iexical2.1

Bnakulated 2.10

U

-Unconditional statement 7.3 &h&ommf~s.l4

Lexiifd 2.1 Program 2.9

V r

Variable 4.1 Variant part 4.6

W Word, Reserved 2.4

I3

M’I’ER~~I’?& $YS’i’EMUF UNITS ( SI UNITS )

Base Units

Quuntity

Length

MMS

Time

Electric current

Thermodynamic temperature

Luminous intensity

Amount of substance

Supplementary Units

Quantity

Plane angle

Solid angle

Derived units Quantity

Force

Energy Power

Flux

Flux density

Frequency

Electric conductance

Electromotive force

Pressure, stress

Unit

metre

kilogram,

second

ampere

kelvin

candela

mole

Unit ‘.

radian

&radian

Unft n newton

joule

watt

weber

tesla

hertz

siemens

volt

Pascal

Symbol

m

kg

S

A

K

cd

mol , L

Symbol

rad

sr

Symbol Definition

N 1N = 1 kg.m/s*

J 1J = 1 N.m

W 1w = 1 J/s

Wb 1 Wb= 1V.s

T 1T = 1 Wb/ms

HZ 1 Hz = 1 c/s(s-1)

S 1s = 1 A/V

V 1v = I W/A

Pa 1 Pa = 1 N/m*