interop/input|output: update documentation

pkg/interop/input/input.go

@@ -1,17 +1,22 @@
+/*
+Package input provides functions dealing with transaction inputs.
+*/
 package input
 
-// Package input provides function signatures that can be used inside
-// smart contracts that are written in the neo-go framework.
-
-// Input stubs the input of a NEO transaction.
+// Input is an opaque data structure that can only be created by
+// transaction.GetInputs and it represents transaction's input. It's similar
+// to Neo .net framework's TransactionInput.
 type Input struct{}
 
-// GetHash returns the hash of the given input.
+// GetHash returns the hash stored in the given input (which also is a
+// transaction ID represented as 32 byte slice containing 256 bit BE value).
+// It uses `Neo.Input.GetHash` syscall.
 func GetHash(in Input) []byte {
 	return nil
 }
 
-// GetIndex returns the index of the given input.
+// GetIndex returns the index stored in the given input (which is a
+// transaction's output number). It uses `Neo.Input.GetIndex` syscall.
 func GetIndex(in Input) int {
 	return 0
 }