Chapter 1 - Preliminaries

1.1 Reasons for studying concepts of PLs

• Increased capacity to express ideas
• Improved background for choosing appropriate lang
• Increased ability to learn new langs
• Better understanding of the significance of implementation (more to do with compiler design)
• Better use of known langs
• Overall advancement of computing

1.2 Programming Domains

• Scientific
  • FORTRAN
• Business
  • COBOL
• AI
  • Lisp, prolog, scheme
• Web
  • HTML, markup, JS & PHP
• Teaching
  • Pascal

1.3 Language Evaluation Criteria

• Readability
  • Simplicity
  • Orthogonality
    • Relatively small set of primitive constructs combined in small number of ways
  • Data Types
  • Syntax design
• Writability
  • Simplicity and Orthogonality
  • Expressivity
• Reliability
  • Type checking
  • Exception Handling
  • Aliasing
  • Readability & writability
• Cost
  • Training to use
  • Actually writing (writability)
  • Compilation
  • Execution
  • System implementation
  • Poor readability
  • Maintenance

1.4 Influences on Language Design

• Computer Architecture
  • von Neumann (fetch/decode/execute)
    • imperative languages (program & data in same memory)
    • won’t be displaced until efficient non-von Neumann system developed for efficient execution of functional languages
• Programming Design Methodologies
  • OOP / Inheritance
  • Procedure-oriented

1.5 Language Categories

• Imperative
• Functional
• Logic
• OO

1.6 Language Design Trade-offs

• Reliability / cost of execution

1.7 Implementation Methods

• Compilation
• Pure interpretation
• Hybrid
• Preprocessors

1.8 Programming Environments

• OS / Editing environment