Chapter 6
   implicit context -- which + to use
   C value model: r-value vs l-value
   immutable -- cannot be changed
   primitive vs object: boxing in Java
   orthogonal -- features can be combined... are independet
   Java -- definite assignment -- no variable is undefined
   precedence and associativity
   short-circuit (Pascal)
       C -- & vs && and | vs ||  -- for logical values
   structured programming   -- vs goto
   recursion -- was not allowed in FORTRAN, had to be requested in PL/I

Chapter 7 --
   type equivalence, compatibility, inference
   system programming and type breaking --
       Looking at the bits of a floating point number!
       https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html
       Math.getExponent()
       Double.doubleToLongBits
   orthogonality
   oddities
       character sets?
           C char is 1 byte
	   Java char is 16 unsigned bits
	   UTF-8 is representation of Unicode with its 1112064 codes
	       can require up to 4 bytes (32 bits)
	       though codes can require up to (21 bits)
       COBOL (and PL/I)
           .......   PIC 9(6).9(2)
       ranges  saw      0..100
   types
       equivalence
       type punning...
       https://en.wikipedia.org/wiki/Fast_inverse_square_root (Quake III)
       


   types are MORE important now
       but what about JavaScript???
       https://javascript.info/types
       JavaScript is what happens when amatuers define programming languages
   https://en.wikipedia.org/wiki/ECMAScript
       http://www.ecma-international.org/ecma-262/9.0/index.html