Essentials of Programming Languages

As used in the Indiana University Course C311

• design and implementation of general purpose programming languages

• understand semantics of languages we use

• understand implementations of languages we use

• choose among general purpose languages

• design and implementation of special purpose languages

• language effect the way we think!

• imperative

• functional

• object oriented

• logic (not in this course)

• concurrent / parallel (not in this course)

• meta-linguistic abstraction

Meta-linguistic abstraction is the solution of problems through custom programming languages.

If you are skilled in the use of meta-linguistic abstraction, and use a programming language that is suited to this programming paradigm,

the only limits on the way you program are in your head!

To use meta-linguistic abstraction effectively, you must

• know what the standard semantic possibilities are

• know how to implement them

• use a language that provides good support for meta-linguistic abstraction (makes it easy to implement custom languages)

Scheme is the best language we know of for this purpose.

It provides excellent support for the following means of implementing a custom language:

• procedural abstraction (with first-class procedures)

• interpreters

• syntactic abstraction (macros)

• compilation

Traditional study of programming language involves

• first a descriptive survey course (organized around languages and/or principles)

• then one or more courses taking an analytic (formal, precise, mathematical) approach to the study of programming language semantics, using a variety of notation and mathematical models

This course

• analytic from the beginning

• uses a single metalanguage: Scheme

• uses a range of models and levels of abstraction

  • from high level (formal semantics) to low level (assembly language), and

  • derive the relation between high and low levels.

The meta-language (Scheme)

• plays the role of a variety of mathematical notations

• executable: ideas come alive, everything runs, test knowledge

• use our programming intuition

• programming assignments build mastery of material

• course not about Scheme (cf. goofy syntax in book)

We emphasize essential

• depth of understanding, at cost of breadth

• with solid foundation, can gain breadth by self study