meljun cortes manual structured programming language csci07

8/13/2019 MELJUN CORTES MANUAL Structured Programming Language CSCI07

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CSCI07 - Structures of Programming LanguagePrepared By: MELJUN P. CORTES

INTRODUCTION

1.1 PROGRAM LANGUAGE DEFINITION

PROGRAMMING LANGUAGE

Is a notation for expressing instruction to be carried out by a computer

Is a communication between the human and the machine and often between one

human being and another.

1.2 REASON WHY STUDY PROGRAMMING LANGUAGE

1. To be able to study a new language2. To increase program vocabulary3. To have a better understanding of the language you are using4. To make it easier to design a new language.. !uit the needs of the system

1.3 THE PROGRAMMING FUNCTION IN SYSTEM DEVELOPMENT

SYSTEM DEVELOPMENT LIFE CYCLE

"igure 1.#

REQUIREMENT SPECIFICATION-This step includes a problem definition as well as

analyses of the current system and of the firm$s goals in developing the newcomputer system.

EVALUATING ALTERNATIVES- These alternative s are tested for feasibility

including technological feasibility %&an it be built'() economic feasibility %&an weafford it'( and behavioral feasibility %&an it be implemented with a minimum traumato the firm and its personnel'(

PURCHASE AND CONSTRUCTION- *nce management decides on the appropriate

system) it must be +built,. "or hardware this almost always means purchase whilesoftware can either be purchased or constructed.

IMPLEMENTING AND TESTING- The various components of the system are

integrated and put into working order. The system is tested for errors and these errorare corrected.

MAINTENANCE-Takes place throughout the lifetime of the computer system

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e/uirement !pecification

0valuating lternatives

-urchase and &onstruction

Implementing and Testing

aintenance


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TRANSFORM

GENERALIZING THE PROGRAMMING FUNCTION

THE PROBLEM

PROGRAMMING MYOPIA-Is characteried by dependence on the particular programminglanguage

THE SOLUTION

In order to step beyond language) we must first of all have at least rudimentary

understanding of many different kinds of languages and many different ways ofprogramming solution. e must understand and generalie the vast conceptualcommonalities in programming languages rather than emphasie the artificialsyntactic differences.

THE FUTURE OF PROGRAMMING

-rograms are getting larger re/uiring more effort out of more programmers over

larger periods of time.

The ability to use the variety of languages will ensure the best fit for the application.

The construction of large program from blocks of relatively independent yet

interrelated program code has been popular for a long time this type of programdesign has been called modular decomposition of programs.

PROGRAMMING FUNCTION SPECIFIC CONCERNS ARE:

hat hardware will be used'

hat people will use the system'

hat procedure will the system implement'

1.4ABSTRACTION FUNCTION

ABSTRACTION- Is the means by which we consider only the information that is elevant tothe problem at hand) ignoring trivial details and unimportant facts'

BLAC BO! MODEL- 5eneral model governing abstraction adapted from the

engineering disciplines.

I6-7T! *7T-7T!

"igure 1.1

1." BASIC PRINCIIPLES OF PL

1.# SYNTA!

ules8 format in writing the program

5rammar

2.# SEMANTICS

The meaning of the different syntactical constructs of -9

3.# PRAGMATICS

The uses) origin and effects of the programming language

1.$ DIFFERENT INTEREST THAT CON%OIN THE STUDY OF PL

1.# PROGRAMMER

Translates the algorithm using a particular -9

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n extensible language enables the programmer to define new languagecomponents which then become indistinguishable from the language$s own built>inprimitives.

The degree %and kind( of interaction of the program with this environment 9I!-) !6*=*9b. !cience80ngineering> =!I&c. =usiness ;ata -rocessing> &*=*9d. !ystems -rogramming> &) dae. rtificial Intelligence> -*9*5f. !imulation> !I79g. 0ducation> =!I&) -ascal

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B. SPECIAL PURPOSE

They cannot be used for any other problem area other than the one forwhich they were designed.!tatistical package. 0xample: -5

The processing environment assumed by the language:

E. BY PROCESSING ENVIRONMENT

. BATCH PROCESSING-The oldest sort of processing environment is one inwhich there is no interaction of any sort with the executingprogram.

=. INTERACTION WITH :

1. H*( U0') Interactive -rocessing(- Is characteried by interaction between the program and its human user8

programmer during program execution.

2. P70,8*+ O=>'8 %eal>Time -rocessing(- processing environment in which external processes) such as physical

ob?ects) interact with and impose strict time constraints on the responsesfrom executing programs.

0xamples: *;79>2) da0xample is robotics) automatic pilots and space vehicles

3. O7') S/5*)' %parallel -rocessing(

C/(8))'( P)/8'00,(- the concurrent execution of two or moresubprogram called processes.

0xamples: *;79>2) da) !99T9@

They operate simultaneously) relatively independently) and maycommunicate with each other and share common resources.

multiprogramming paradigm or organiing principlesupported by the language.

F. BY PROGRAMMING PARADIGM

A. PROCESS CENTERED- concerned with the details ofcomputing a solution and with the process ofproblem decomposition.

B. DATA CENTERED- !upport the development ofprograms by way of the formal specification of the datathat will be manipulated.

data> centered language is one in which programs are developed bymeans of formal specification of the data that is to be manipulated.

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1.?HISTORICAL DVELOPMENT OF PL

CHARLES BABBAGE-

"ather of modern computer- "irst computer architecture- ;evelop Difference Engine- ;evelopAnalytical Engine

D,')'(8' E(,('- a mechanical device that can perform

simple mathematical calculation> see figure b

A(*+,8*+ E(,('- this device provided a changeable

se/uence of numerical operations andinternal storage for data.

LADY AGUSTA ADA- &ountless of 9ovelace) daughter

of the poet 9ord =yron- The "irst &omputer -rogrammer- !he coded programs for nalytic 0ngine

using punched cards or also called asAac/uards.

- &readited with innovating the loop) orepition) construct.

EDVAC- Electronic Discrete Variable Arithmetic

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%OHN VON NEUMANN

> ;eveloped the 0;C&


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Computer

- configuration in which the processortightly coupled to primary storage)primary storage is large enough to storevast amounts of data along with theprogram code) and operations are

executed se/uentially without theparallelism that was needed on theearlier machines to counteract theirextremely limited storage capabilities.

- this design has influenced many of thehigh level programming language.

UNIVAC - UNIVersal Automatic Computer

- The first computer to be available forcommercial sale.

- The first electronic computer producedspecially for commercial use and onetechnological feature is that its usesvacuum tubes

HOWARD AIEN- ;eveloped the @ I

MAR I- the pre>first generation machinery- it was also known as the utomatic !e/uence> &ontrolled &alculator

THE SOFTWARE LADDER

A. T7' 10G'(')*,/( 1@3&- 1;"2#

The era of machine language programming

ll coding was done in machine language that

is) the computer own internal %binary> based( instruction set

The word wasn$t programming then) but coding)and programmers were called coders.

G)*8' M))* H/


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B. T7' 2(9G'(')*,/( 1;4;- 1;"$#

The pre> compiler era) saw the development and distribution of machine> code

subroutines) interpretive routines) automatic code generators) andassemblers.

Aohn auchly) proposed and implemented

+!hort> *rder &ode, or +!hort &ode, for the =I6& % =inary utomatic &omputer(

computer as a set of interpretivesubroutines stored in memory

B' H/+=')/() developed the

S/) M')' G'(')*/)which was thefirst attempt toward using a computer

to write programs.

T7' P)'


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C. T7' 3)9G'(')*,/( 1;"4-


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PL1- -rogramming 9anguage8*60- The language to end all languages,.- It was a state>of>the>art language that contained virtually every

conceivable element of language design.- It inherited the features of "*T6 %its expression and statement

syntax) share data) and the external procedure() &*=*9 % its data description)record and file handling) and report generation facilities() and 95*9 %its blockstructure) type declarations) and recursion(.

LOGO- ;eveloped by !eymour -apert of IT) along with a a group of

researchers and consultants as a &ambridge research firm.- It was designed specifically for mathematics education and was

actually used experimentally in elementary school classroom in 1FBD

FORTH- ;eveloped by &harles H. oore for scientific and engineering

applications yet allow for faster programming using fewer lines of code.

SIMULA

- ;esigned in FB2 by @risten 6ygaard and *le> Aohan ;ahl at the6orwegian &omputing &enter under contract with 76IC&

- It was motivated by a desire to create a programming language for simulationapplications> techni/ue of operations research that has since beensuccessfully used in a large number of diverse applications areas > whichwould also serve as a medium for describing the system under study.

ALGOL$?- revised and extended version of 95*9- Introduced the user> defined data type and the pointer type ) both

significant features of -ascal.

PASCAL- ;eveloped by 6iklaus irth) named after the "rench philisopher and

mathematician =laise -ascal- It was intended to illustrate the direction that 95*9 should have

taken .

C LANGUAGE- In 1FD2) =ell 9aboratories$ @enneth Thompson and ;ennis itchie

developed the & language for coding the routines of the 76IJ operatingsystem.

- & was an extension of the = language> also designed by Thompson>which itself drew heavily on a earlier systems programming language) =&-9.

MODULA 2- odular 9anguage- direct descendant of -ascal is another high level language with

facilities for systems programming.

- Is characteried by strong typing and syntactic style) and) of course)the module) a type of block that can be compiled independently and easilyassembled into program libraries.

ADA- 6amed after the 1stcomputer programmer 9ady ugusta da

9ovelace) designed according to specifications developed by the 7.!;epartment of ;efense.

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- It was intended for the programming of embedded computersystems

D. T7' 47G'(')*,/(- a 4thgeneration language is declarative) in other words) its

instructions to the computer concentrate more on what is to be done ratherthan on describing in detail how to do it.

- -rogramming are sorter) and easier to code) debug) and maintain

PROLOG- -rogramming in 9ogic- It was developed by lain &olmerauer and -hilipe oassel of the

7niversity of arseille$s artificial group) in collaboration with obert @owalskiof the 7niversity of 0dinburgh.

- It has a firm mathematical basis) grounded as it is in the principles ofpredicate calculus.

OPS- *fficial -roduction !ystem- ;eveloped at &arnegie ellon 7niversity in 1FD#- Is a production> system) or rule> based) language used in the field of

artificial intelligence.

SMALLTAL- designed and implemented in 1FD2 at Jerox -alo esearch &enter

%-&(.- The language that defines the ob?ect oriented approach to

programming.

1.;WHAT MAES A GOOD PL

1. W),*=,+,- easy for the programmer to design) code) test) run) document and

modify programs.- !yntax rules will be clear) simple and consistent

2. E))/) C7'8,(- -9 contains debugging facilities for finding errors that do occurs

3. R'*9*=,+,- assumes that the program with be read by other technical personnel)

non> technical ) programmers and users.- It is clear) understandable) and easily modifiable.

4. S'+- D/8'(*,/(- other forms of documentation usually attached to the source code

for the benefit of maintenance and programming

". E'(0,=,+,- if it enables the programmer to define new language components.

$. P/)*=,+,- ensure that the language works in the same way on these different

machines so that a program written in the language and tested on aparticular computer will still work with other computer.

&. E,8,'(8- 0fficient use of memory space %as little as possible( and computer

processing time %as fast as possible(.

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1.1@ CHOOSING A PROGRAMMING LANGUAGE

FEATURES OF THE APPLICATION

1. P=+,8 60. P),6*' C/in data types and data

structures for the application area.

2. P)/)*,( E(6,)/('(- lso called a Software Development Environment) is a set of tools

that includes programming language and serves to aid in programdevelopment.

0xample: Translator 0ditor) 9inker) nd *nline Help

3. L'*)(,( C)6'- How easy will it be for a programmer to learn this -9.

CHAPTER 2

LANGUAGE PROCESSOR AND RELATED CONCEPTS

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Assembly LanguageStatement

Assembly LanguageStatement

ASSEBLE!

INTERPRETER

ac"ine languageInstruction



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TRANSLATORSFIGURE 2.0

translator program accepts high>level language statements as produces thee/uivalent executable machine>language instruction.

2.1 TYPES OF LANGUAGE PROCESSOR

1.# ASSEMBLER- Is a translator program that translates assembly language to

machine language.

2.# INTERPRETER- type of language processor that operates one instruction at a time)

translating a high>level language statement and executingimmediately.

- 5enerally run more slowly than compiled programs.

3.# COMPILER- Is a translator program) which transforms a source program)

composed of high>level language statement into an ob?ect programconsisting of machine>language executable code.

OB%ECT PROGRAM machine>executable program produced as output from a compiler.

SOURCE PROGRAM program written in a high>level language and then input to the compile process.

Compilation Occurs in ! Broad P"ases

1.( ;ecomposes the source program into small identifiable units and analyes it forsyntactical accuracy.

2.( Takes the machine>code modules associated with the basic units identified in the

in the 1stphase and uses them to compose the ob?ect program.

2.2 THE COMPILE PROCESS

SOURCE PROGRAM ANALYSIS The first phase of the compile process encompasses the lexical

analysis and the syntactic analysis) producing the symbol table andintermediate %assembly>level( code.

LE!ICAL ANALYSIS

Is concerned with the actual text of the program) which is

considered to be a meaningful se/uence of characters.

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Assembly LanguageStatement C#PILE!



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TOENS

!eparate pieces of programs

re the basic symbols used by the program: identifiers) operators)

punctuation) language keywords) constants.

SYMBOL TABLES

lso called the dictionary

ap program symbols such as variables with their properties such

types) sie) and relative location.

SYSNTACTIC ANALYSIS

Is concerned with identifying the logical structure of the program in

accordance with the rules of grammar governing the high levellanguage

PARSE TREE SYNTA! TREE

&ontains the hierarchy of operations in the high>level language

statements.

0very leaf node contains one of the symbols %tokens( in the

statement

ERROR HANDLER ;uring the lexical and syntactical analyses) information regarding

an error encountered is sent to the error handler module of thecompiler) which will arrange to print out a message to the user.

INTERMEDIATE CODE GENERATION

The result of the lexical and syntactic analyses and the information

in the symbol table are brought together to produce program code insome intermediate from similar to assembly> language code.

*utput from the syntactic analysis step) the intermediate code

serves as input to the code generation step.

*utput from the syntactic analysis step the intermediate code

serves as input to the code generation step.

OPTIMIZATION

To produce efficient code

To make more efficient use of main storage and processor time

To correct + bad programming practice,

"or detecting code that can be moved out of a loop % to improve the

efficiency of the program) and its logical structure(.

;etection and elimination of dead code

DEAD CODE is a program code that is accessible in the normal

processing of the program and will conse/uently never be executed.

CHAPTER THREE

MA%OR ASPECTS OF PROGRAMMING LANGUAGE

DATA

=its of information to be manipulated

3.2 DATA PRIMITIVE OPERATION

I. CONSTANT

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Is a data item that remains unchanged throughout the

execution of the program

Calue is unchanged through the program

USES OF CONSTANTS

1. L,')*+

- is a data value that is used explicitly or literally in a programA. N'),8*+ L,')*+ /) N'),8 C/(0*(

- aybe made up of numeric digit # to F and special character K) >)and

B. S),( L,')*+- aybe composed of any valid characters in the language character

set and is often enclosed in single or double /uote.0xample : L -rogramming 9anguage$

C. L/,8*+ C/(0*(- True or "alse

2. N*'9 C/(0*(

- re sometimes termed symbolic constant or figurative constants.- 9ook likes variables because they are identified by a name.0xample : %&*=*9 language(

!-&0 M0* HI5H C970

II. VARIABLE

Is a receptacle for storing data value and each variable is associated

with a domain of allowable values.

0nable programmer to construct program for which the actual data

values are not needed until execution.

Calue is changed depending on certain conditions.

CONTROL VARIABLE- 0xist only in relation to the executing program or in the context of

algorithmic computation and have no relevance to the outside world.0xample :

Index Cariable % is used to control iteration(

ecord 6ames

"ile 6ames

COMPONENT OF A VARIABLE

1. 6ame2. Type8 !ie> ost important. It determines the domain of values that thevariable is allowed to take on and the set of operations that may beperformed on the variable.3. Calue4. !torage 9ocation

VALUES MAY BE PROVIDED FOR VARIABLE IN ONE OF THREE WAYS :

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1. Initialiation when the variable is createdvalued entities operated upon by logical operators such as

and or) not.ay be taken such values true or false or #) 1.

4. A99)'00

*#. L*='+> more properly called a program elements that a data element is

actually the address of a program statement.

> *perated by the 5*T* operation

=#. P/,(')>eference or +point to, are another data element.

reference to unnamed data ob?ectII. COMPOUND DATA ELEMENTS

!ometimes considered primitive data elements and sometimes

classified as data structure.

1. S),(

n ordered se/uence of character of dynamically changing sie.

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DATA STRUCTURE

n organied collection of data ob?ects sub?ect to certain allowable

operations.

I. L,('*)

Is one in which the individual components are unordered se/uence.

*. S,


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F,)' 3.@9**


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2. SUCCESSOR

Its can be stated as: N is successor of -.

hat data element is next'

6ode %-( 6ode %N(

F,)' 3.1

3. EQUIVALENCE

It can be stated as: is e/uivalent to =.

Is implied in e/uality) in other words if and = are e/ual) they must be

e/uivalent.

OPERATION ON DATA STRUCTURES

1. CONSTRUCTOR

&reate or build> up data structure

2. DESTRUCTOR

;estroy) or break down data structure

3. ACCESS

-rovides access to the individual components and to groups of a

data structure by means of one of a variety of referencing methods.

ccess may be accomplished by:

. =y Nualified 6ame 0x. Index @ey=. =y location or subscript

0x. rray&. =y 6ame

%by assigning names to data structures(

4.# PREDICATES

These =oolean functions test a data structure for the presence of a

particular propertyFILE STRUCTURE

The organiation of data residing in secondary storage and sub?ect to

input8output related operations.

FILE

Is a collection of related records) related to a particular application.

RECORD

Is a collection of related data items) or fields) related to a single ob?ect ofprocessing.

FIELD Is a data item) a piece of information) either a data element or a structured data item)that is contained within the record.

CHARACTERISTICS OF FILE

1.# ACCESS MODE

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The mode) or direction) of access from any particular file is determined by

whether the file is to be used for input) for output or both.

A. I(


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ssigns the value of the current or re/uested component record to a

designated record variable or input buffer variable.

4. WRITE

&reate anew component record

". EOF

Tests for + end>of>file, and returns a =oolean value.

$. MAINTENANCE

"or maintenance files re/uiring regular maintenance %aster "ile(.

A. S/),(B. M'),(C. U scale direct> access storage deviceDBMS D**=*0' M*(*''( S0'#

!pecialied ! used to access a database

It is the software interface between the physical storage of the data and the use of

the data in various applications.

DATA ABSTRACTION

language facility that integrates the representation of a programmer> defined data

ob?ect and the operations that may be performed on that data ob?ect into a singlesyntactic unit.

3.3 S''(8' C/()/+

!tructures which affects the order of execution of statements within programs.

A. S)8)'0 U0'9 ,( E &ode !e/uence2. Tree> epresentation3. Infix) -refix) -ostfix 6otations

B. S)8)'0 U0'9 B'5''( S*''(0 /) G)/< / S*''(0

1. B)*(87,(*. C/(9,,/(*+

- I 7'( '+0'

- C*0'- O( G// O( G/S=

=. U(8/(9,,/(*+- G//- G/S=- E,- R')(

2. L//


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a. 5eneralb. !pecific

C. S)8)'0 U0'9 B'5''( S=


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C+*00,,8*,/(0:. B,(*) O valued arithmeticexpression.

RELATIONAL OPERATORS

K K K #

may operate on virtually all types of data and form conditions.

CONDITION

is an assertion of a relation that computes to a =oolean value.

LOGICAL OPERATORS *(9 /) (/#

*perate on =oolean data and enhance conditions.

CONDITIONAL E!PRESSION

is a form of expression that originated with 9I!-) made its way into 95*9S() and is

currently used in &.

0xample : %& 9ang.(

1. =O %=( ' : #If the expression %=( is true) then=O < otherwise =O#

2. I" %=( =O else bK#

PRECEDENCE OF OPERATORS%"rom Highest -recedence to 9owest(

# J - K K K

4.2 REPRESENTATION OF E!PRESSIONS

1. P*)'(7'0,'9 F/) I(, F/)#

The one most familiar to us and most commonly relied on in programming.

The expression is represented as a linear se/uence of operators and

operands) which is ordered so as to exploit as much as possible the built> in

precedence rules of each language.

F++ P*)'(7'0,'9 F/)

;oes not rely on any precedence rules at all

meljun cortes manual structured programming language csci07

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