Course List

Typechecking - Checking

Java-light: Java w/o classes, w/ primitives, strings, functions and maths. Its implicit coercion table:

From \ To	int	double	string
int	---	Yes	Yes
double	No	---	Yes
string	No	No	---

It has three + and two - functions:


          +: int -> int -> int
          +: double -> double -> double
          +: string -> string -> string
          -: int -> int -> int
          -: double -> double -> double

Note: we describe a function using arrows with the last one as the return type.

Typechecking - Checking

Checking: What function is that? Find all functions with that name, put them in order by type, try them one by one.

Order of function calling is important
Order of operations: PEMDAS

Examples of the order of operations in Java-light:

Expression	Correct	Wrong	Remark
a + b + c	(a + b) + c	a + (b + c)	Associativity from left to right
*a + b c**	a + (b * c)	(a + b) * c	Precedence of * higher than +
*a b / c**	(a * b) / c	a * (b / c)