Com S 342 meeting -*- Outline -*-

* summary of syntax abstraction

** translational or sugaring approach to extending languages

------------------------------------------
	MAKING THE LANGUAGE SWEETER

Syntactic abstraction = syntactic sugar

  problem: 


  solution: 



  advantages: 




------------------------------------------
	... common pattern, tedium

	... new syntax
	    semantics by translation
			to old pattern

	...   no need to change compiler
	      no additional interactions
	      but new syntax may allow more
		  optimizations (as in case)

	Q: What statements in C are defined by syntactic sugar in this way?
		for, break, continue

** automation principle

------------------------------------------
	AUTOMATION PRINCIPLE

A language should automate


Examples:




Bonus:


------------------------------------------
	... common or tedious patterns.

	Q: What examples have we seen?

	binding with lambda ==> let
	boolean-valued ifs  ==> and, or
	nested ifs          ==> cond
        tests against value ==> case

	... the pattern may be faster than the general case