Added some helpful comments to the creature command

cmd/creature/main.go

@@ -40,6 +40,9 @@ func main() {
 	}
 }
 
+// read implements a basic input function for the creature. It waits until it
+// has recieved one byte of user input, and then pushes that byte onto the
+// stack.
 func read(machine *cre.Machine[int]) (stop bool) {
 	ch := []byte{0}
 	os.Stdin.Read(ch)
@@ -47,15 +50,22 @@ func read(machine *cre.Machine[int]) (stop bool) {
 	return
 }
 
+// write implements a basic output function for the creature. It pops one byte
+// off of the stack, and writes it to stdout.
 func write(machine *cre.Machine[int]) (stop bool) {
 	print(string(rune(machine.Pop())))
 	return
 }
 
+// logLine prints a message to stderr.
 func logLine(message ...any) {
 	fmt.Fprintln(os.Stderr, message...)
 }
 
+// readFile reads data from an io.Reader into a program slice and a block slice.
+// Data in the file is represented by signed hexidecimal numbers, separated by
+// whitespace. Three dashes (---) divide the block data from the program data.
+// See examples/echo.
 func readFile(reader io.Reader) (program []int, block []int, err error) {
 	scanner := bufio.NewScanner(reader)
 	scanner.Split(bufio.ScanWords)
@@ -100,5 +110,3 @@ func readFile (reader io.Reader) (program []int, block []int, err error) {
 	program = program[:programLen]
 	return
 }
-
-