Programming Language Evaluation

1
Programming Language Evaluation

• C Programming
• Saleena V.E.O Abdul Kader
• WGA 040013

2
Introduction

• Who designed it?
• Bjarne Stroustrup at Bell Labs( 1983)
• Originally known as C with Classes
• Adopt C, taken from the origin of C and ,
  from the operator used in language.
• Cfront was a traditional compiler that did
  complete syntax and semantic checking of the C
  source
• Why?
• Sole purpose of making the process or writing
  good programs easier and pleasant for individual
  programmer

3
Programming Paradigm

• The style that affects the way the programmers
  may design and organize the programs written in
  C.
• C offers multiparadigm programming.
• Procedural Programming
• Object-Oriented Programming
• Free Form
• Generic Programming
• Statically Typed

4
Features

• Operators Preprocessor Directives
• include as the preprocessor directives
• .h files as the header files used in the
  program, serves to simplify the functions called
  within the program.
• Templates
• functions that can be used and called several
  times.
• Polymorphism

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Features

• Abstractions
• Encapsulation
• allowing all members of a class to be declared as
  either public, private, or protected.
• A public member of the class will be accessible
  to any function.
• A private member will only be accessible to
  functions that are members of that class and to
  functions and classes explicitly granted access
  permission by the class ("friends").
• A protected member will be accessible to members
  of classes that inherit from the class in
  addition to the class itself and any friends.
• Inheritance
• Inheritance from a base class may be declared as
  public, protected, or private

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Major Application Area Implementing C

• iPod user interface ( using Pixo application
  framework written in C)
• AT T largest US telecommunications provider
  1800 service, provisioning systems and systems
  for rapid network recovery after failure
• Adobe Systems
• Visual Studios
• Google
• IBM OS/400,K42.
• Bloomberg assist investors with real-time
  financial information
• Intel Vtune performance analysis software,
  compilers optimizers

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Claims Made Supporting the Language

• Security
• Allow unsafe code
• To access hardware directly
• To achieve optimal run-time space performance
• To be compatible with C
• Using the standard library
• for example, using stdvector or stdstring
  instead of a C-style array--can help lead to
  safer and more scalable software.
• Portability
• defines many new keywords,
• such as new and class, that may be used as
  identifiers (e.g. variable names) in a C program.
• Even though the latest C standard does not
  require a "return 0" in main, some older
  compilers such as Microsoft Visual C 6 give
  warnings or errors for a main without a return
  statement and may not generate correct object
  code.
• designed to be as compatible with C as possible,
  therefore providing a smooth transition from C
• avoids features that are platform specific or not
  general purpose
• designed to function without a sophisticated
  programming environment

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• Efficiency
• reduced programming errors through abstraction
  and simplification of interfaces, while
  maintaining the levels of efficiency that C
  programmers have come to expect both from the
  language and its libraries.
• Use of standard library / specific library
  functions, access of library through the headers,
  compared to C, C have only 69 standard header,
  where 19 are depreciated.
• In terms of memory, C can allocate arbitrary
  blocks of memory
• Extensibility/Maintainability
• Use of modularity properties enable ease of
  maintaining the program, such as classes, files
  etc.
• Enables information sharing through FRIENDS of
  classes

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Compiler Model
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Description of Language ( as used in the
prototype)

• Scalar Data Objects

// the declaration of variable type used in
getStudentDetails function string fName
string Lname int ID int noOfCourses char
paid bool isFeePaid string cName string
cNo int credits int count int i
courseType courses6 char cGrades6
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• Structured Objects use of arrays records

courseType courses6 char cGrades6
for(count0countltnumberOfStudentscount)
infilegtgtfNamegtgtlNamegtgtIDgtgtisPaid
if(isPaid"Y") isFeesPaidtrue else isFeesPai
dfalse infilegtgtnoOfCourses for(
i0iltnoOfCoursesi) infilegtgtcNamegtgtCnogtgt
creditsgtcgradesi coursesi.setCourseInfo(c
Name,cNo,credits) studentList(count.setIn
fo(fName,LName,ID,noOfCourse,isFeesPaid, cour
ses,cGrades)
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• Composite Objects

• A string data type was composed from series of
  character.
• Main purpose is to do the following-
• - Concatenation, the operation of joining two
  character strings to make one long string
• - Relational operations on string
• - Substring selection using positioning
  subscripts
• - Input-output formatting
• - Substring selection using pattern matching
• - Dynamic string

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Abstract Data Types

• allowing the user to encapsulate both data and
  actions into a single object
• Inheritance is an important feature of classes

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Active Objects

• Its a special method, called as the body, most
  of the time would be defined in the similar way
  as the constructor/destructor that runs on a
  thread attach to the object.
• This body can decide when a method may be called
  (by means of an accept statement) by the main,
  processes or the other object bodies.
• However, the active objects are not being used in
  the prototype due to the reason that the
  simplicity of the prototype does not require one.

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Design Mistakes and Problems

• Implementation-specific Issues
• The C standard does not cover implementation of
  name decoration, exception handling, and other
  implementation-specific features, making object
  code produced by different compilers incompatible
  beta compiler of Borland C Builder X was also
  released with export function.
• Portability Issues
• Static constructors
• Do not use C Standard Library features,
  including the iostream.
• Do not use namespace facility.

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Suggestions

• To learn C better, you will need
• a good book
• a good compiler and
• a development environment.
• Visual Basic which is very much improved as the
  Visual Net version and can match C and other
  languages by now.
• Often compared to single-paradigm object-oriented
  languages such as Java, on the basis that it
  allows programmers to "mix and match"
  object-oriented and procedural programming,
  rather than strictly enforcing a single paradigm

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References

• Pra01 Pratt, T. W. and M. V. Zelkowitz (2001).
  Programming Languages Design and Implementation,
  Prentice Hall.
• Gar05 Gardos, A. (2005). "New functions
  GetShapeFill, ChangeShapeFill, ChangeProperties."
  
• from http//avax.invisionzone.com/index.ph
  p?showtopic30.
• Han01 Handford, F. J. (2001). "C tutorial
  chapter 2, variables." from http//www.eastcoastga
  mes.com/cpp/chapter2.html.
• http//en.wikipedia.org/wiki/Visual_C_Plus_Plus
• http//en.wikipedia.org/wiki/The_Design_and_Evolut
  ion_of_C2B2B

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Evaluation Results

• The evaluations are made based on my experience (
  not that experienced though) and also by
  comparison to other languages such as C and Java.
• do you have any basis to agree or disagree with
  any claims made of its security, portability,
  efficiency, extensibility/maintainability?
• In terms of security, even though C provide
  flexible declarations compared to C , C may
  need to be improved in the use of export
  functions. For some compiler, export functions
  may not work, and hence, even MS Visual C also
  do not support this.
• C are not quite portable in the sense that, it
  depends mostly on WHICH COMPILER being used.
  Compared to the older version of C, the header
  files are accompanied by .h, but the newer
  versions do not require one.
• It is efficient in terms of memory management and
  it is also easier to maintain since it practice
  modularity in the program.
• what aspect of this language did you find most
  difficult to learn/understand?
• The coding in which some conventions may not
  comply to the standards given.
• The compilation process especially when it comes
  to using different compiler.
• how would you rate the programming environment? 
  compiler/interpreter messages?
• Each different compiler represents different
  style of accepting the preprocessor directives,
  and therefore, with C, regardless of Visual C
  or Turbo C( or any C program type),
  highlighted the error and pinpoint respective
  message with definition of which error occurring.
  Therefore, I find this to be beneficial, instead
  of trying to figure out what went wrong with the
  codes.

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Evaluation Results

• would you use this language again and if so what
  for? if not, what would you choose to use instead
  and why?
• I would choose this language in the future but
  for the purpose as the background to learn and
  understand other C compiler implementation.
• However, I would not limits myself to learn new
  language implementation when the need arises,
  especially the languages that provides the ease
  of use with GUI properties.
• design mistakes (in your opinion or the opinion
  of others)? Have they been corrected in other
  languages that were a follow-on. What if anything
  is missing in your opinion?
• Newer languages are created so that it may
  complement the characteristics that are not quite
  adequate in the older version. Therefore, from my
  opinion, any features that are not readily
  available in the current C programming
  languages used may be corrected in other
  languages. Even though some might not be as
  powerful as C, however, it serves as the basics
  to implement the object-oriented properties.

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The end.