CSC302.01 2007S, Class 01: Introduction to the Course

Admin:
* Do Wednesday's readings (distributed in class).
* HW1: Intro Survey (due Wednesday).
* Upcoming talks (extra credit for attending)
  * Johanna Meehan on vocation, Thursday, 11:00 a.m.
  * John David Stone on Life, Thursday, 4:15 p.m.

Overview:
* What is a programming language?
* How should we study programming languages?
* Why study programming languages?
* Course details.

/What is a Programming Language?/

* DK: A grammar for instructing machines how to do things
  * SS: A grammar is syntaxes and semantics
  * EO: A syntax is a way to formally structure words/commands
  * KG: A semantics gives the meaning of the language
  * KG, waking up: Syntax tells you how to say it, Semantics
    tells you what you said.
  * JT: The language itself does not directly instruct the machine;
    rather, it is traditionally compiled into a language that the
	hardware of the machine can interpret ("machine code")
* Refinement (group): A language (syntax and semantics) in which
  a "programmer" can write programs that (eventually) instruct
  the computer on how to do things.
* DD: Humans are also an audience
* Refinement: Programming languages are languages in which one
  can express computation for execution by a computer or understanding
  by a sentient being.

Why are we spending a semester on languages?
* We should know some theory, not just practice.
  * We do some theory of languages in 341.
  * This class focuses more on the general design - What makes a
    language good or interesting 
* We should know some practice, not just theory
  * We will also discuss some language issues that professional
    programmers use, but that we don't necc. cover elsewhere in
	the curriculum.
	* Continuations
	* Reflection or Introspection in OO languages
* Permit Grinnell graduates to adapt to other languages
  * Historical import: It used to be that Functional Programming and
    Object-Orietned programming were only covered in this class.
* EO: Opportunity to unify the piecemeal ideas we've learned in other
  classes (and "piecemeal" is intended as a compliment)
  * Unfortunately, Sam likes thinking in piecemeal.
* SR: Evidence that any sufficiently complex program requires its
  own own language 
  * It helps to know some of the issues in designing a language
* Past students: Helps you choose the right language (or paradigm)
  for the task.
* Past students: If we talk about compilation, can think about how
  to write more efficient code
  * E.g. In tail recursion, the recursive call is the last thing
    you do.
	* Hence, instead of using a call stack, the compiled code can
	  simply jump to the beginning
* SR: Language wars!

How do we study languages?
* Implementation
* "Language of the Week"
* Syntax and Semantics
* Unifying design issues
* Hybrid
  * A bit of implementation of Scheme
  * Languages of the week:
    * PostScript
	* Prolog
	* SQL
	* Ruby
  * Syntax and Semantics - not much this semester
  * More on languages you know
    * Higher-order programming in Scheme
	* Continuations in Scheme (and their use in Web servers)
	* Introspection in Java
	* More practice in C

How the course works:
* Before every class, you do some reflective reading (10-40 pages)
* 8 p.m. the night before: Send me reflections on each reading
* Sam synthesizes class from the comments/questions
* Discuss reading and related issues in class

Also:
* Some homework assignments
* One group presentation at the end of the semester
* Midsem
* Final