BSV by Example - Computation Structures Group

– instantiating a module and returning its interface
– invoking an ActionValue and returning its value.
To demonstrate variable declaration and initialization syntax, we’ll be working with the example in
Appendix A.3.1. The syntax in this example is more important than the functionality.
Our example has a structure representing a 2-dimensional coordinate:
typedef struct { int x; int y; } Coord
deriving (Bits);
We’ll describe structs in more detail in Section 10.1.3, but will rely here on their familiarity from C.
The above defines a new type Coord with two int fields (members) called x and y. The “deriving
(Bits)” phrase instructs the compiler to pick a canonical representation, here the obvious 64-bit
value concatenating the two 32-bit fields.
4.1.1 Side-effect initialization
One type of side-effect initialization is instantiating a module and returning its interface. Consider
the following statement:
FIFO#(Coord) fi