By Herbert J. Bernstein

© Copyright 2000 Herbert J. Bernstein

Organizing code into subprocedures and functions can improve the readability and maintainability of software.

• Suprocedures -- optionally parametrized sets of statements
• Functions -- subprocedures that return values
• Calling sequences
  • Positional parameters lists
  • Keyword-value parameter lists
  • Non-local and implicit parameters, side-effects
  • Direction of information transfer
  • Transfer of values, pointers, reference structures
  • Symbolic manipulation, lazy evaluations
  • Variable length argument lists
  • Recursion
    • Dynamic allocation of context information
      • Stacks
        • Common stack
        • Stack per variable
        • Linking frames
        • Displays (index array for frames)
      • Lists
• Passing complex structures
  • Strings, structures, arrays, files
  • Extra arguments for related data
  • References, handles, reference counters
  • Garbage collection
• Declarations, validation of types, libraries
• Issues in Fortran and Algol
  • Clobbering of constants in Fortran
  • Stacks and recursion in Algol