Coding%20Standards

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Lecture 20 Coding Standards Tools for Debugging 1
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Coding Standards

• Or
• How to Pound all of your odd-shaped programmers
  into a one size fits all hole

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I think there may be a bug in Joes Code - Please
Fix

• func GreenEggsNHam(Not SamIAm, Green EggsNHam)
• foreach Green TryThem in SamIAm
• do EatThem(TryThem) false
• NotInACarNotOnABus(EggsNHam)
• func NotInACarNotOnABus(Green EggsNHam)
• EatThem(EggsNHam) true
• NotOnAPlane(EggsNHam)
• foreach NotLikeThem SamIAm of EggsNHam do
• if not EatThem(SamIAm) then
• NotInACarNotOnABus(SamIAm)
• IDoNotLikeThem(EggsNHam)

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Joes Code Following a Sane Coding Standard . . .

• func DepthFirstSearch(graph G, vertex v)
• foreach vertex w in G
• do Encountered(w) false
• RecursiveDFS(v)
• func RecursiveDFS(vertex v)
• Encountered(v) true
• PreVisit(v)
• foreach neighbor w of v do
• if not Encountered(w) then
• RecursiveDFS(w)
• PostVisit(v)

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What are Coding Standards

• Coding standards are guidelines for code style
  and documentation.
• The dream is that any developer familiar with the
  guidelines can work on any code that followed
  them.
• Standards range from a simple series of
  statements to involved documents.

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Areas Typically Covered

• Program Design
• Naming Conventions
• Formatting Conventions
• Documentation
• Possibly Even Licensing

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Why Have Coding Standards

• Greater consistency between developers
• Easier to develop and maintain
• Saves time and money

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Prime Directive

• Document every time you violate a standard.
• No standard is perfect for every application, but
  failure to comply with your standards requires a
  comment

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Amblers Law of Standards

• Industry Standards gt organizational standards gt
  project standards gt no standards
• The more commonly accepted a standard the easier
  it is for team members to communicate
• Invent standards when necessary, but dont waste
  time creating something that you wont be able to
  use later.
• All languages have recommended coding standards
  available. It is well worth your effort to find
  and use industry standards
• Push for organizational standards whenever
  possible

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Good Coding Style

• Names
• Use full English descriptors
• Use mixed case to make names readable
• Use abbreviations sparingly and consistently
• Avoid long names
• Avoid leading/trailing underscores
• Documentation
• Document the purpose of every variable
• Document why something is done not just what

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• Accessors
• use getVar() and setVar() functions on all class
  variable unless class is being used solely as a
  data structure (OOP)
• Member Functions Documentation
• What and why member function does what it does
• Parameters / return value
• How function modifies object
• Preconditions /Postconditions
• Concurrency issues
• Restrictions
• Internal Documentation
• Control Structures
• Why as well as what the code does
• Difficult or complex code
• Processing order

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Three Rules

• Coding standards neednt be onerous - find a
  standard that works for your team.
• Standardize early - the effort to bring your old
  work into the standard will be too great
  otherwise.
• Encourage a culture where standards are followed.

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Examples of Coding Standards

• http//www.ambysoft.com/javaCodingStandards.html
• http//www.swtech.com/java/codestd/
• http//ccs.hst.nasa.gov/ccspages/policies/standard
  s/coding_standards.html
• http//www.scriptics.com/doc/styleGuide.pdf