syscall/js: improve documentation about mappings to JavaScript values

This commit moves the documentation about how Go values are mapped to
JavaScript values to the functions that apply the mapping, instead of
mentioning them in the documentation of the types being mapped. This
should be easier to read.

Change-Id: I2465eb4a45f71b3b61624349e908a195010a09f1
Reviewed-on: https://go-review.googlesource.com/126856Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/syscall/js/callback.go

@@ -43,15 +43,12 @@ var (
 )
 
 // Callback is a Go function that got wrapped for use as a JavaScript callback.
-// A Callback can be passed to functions of this package that accept interface{},
-// for example Value.Set and Value.Call.
 type Callback struct {
 	Value // the JavaScript function that queues the callback for execution
 	id    uint32
 }
 
-// NewCallback returns a wrapped callback function. It can be passed to functions of this package
-// that accept interface{}, for example Value.Set and Value.Call.
+// NewCallback returns a wrapped callback function.
 //
 // Invoking the callback in JavaScript will queue the Go function fn for execution.
 // This execution happens asynchronously on a special goroutine that handles all callbacks and preserves

src/syscall/js/js.go

@@ -216,7 +216,7 @@ func (v Value) Get(p string) Value {
 
 func valueGet(v ref, p string) ref
 
-// Set sets the JavaScript property p of value v to x.
+// Set sets the JavaScript property p of value v to ValueOf(x).
 func (v Value) Set(p string, x interface{}) {
 	valueSet(v.ref, p, ValueOf(x).ref)
 }
@@ -230,7 +230,7 @@ func (v Value) Index(i int) Value {
 
 func valueIndex(v ref, i int) ref
 
-// SetIndex sets the JavaScript index i of value v to x.
+// SetIndex sets the JavaScript index i of value v to ValueOf(x).
 func (v Value) SetIndex(i int, x interface{}) {
 	valueSetIndex(v.ref, i, ValueOf(x).ref)
 }
@@ -254,6 +254,7 @@ func valueLength(v ref) int
 
 // Call does a JavaScript call to the method m of value v with the given arguments.
 // It panics if v has no method m.
+// The arguments get mapped to JavaScript values according to the ValueOf function.
 func (v Value) Call(m string, args ...interface{}) Value {
 	res, ok := valueCall(v.ref, m, makeArgs(args))
 	if !ok {
@@ -272,6 +273,7 @@ func valueCall(v ref, m string, args []ref) (ref, bool)
 
 // Invoke does a JavaScript call of the value v with the given arguments.
 // It panics if v is not a function.
+// The arguments get mapped to JavaScript values according to the ValueOf function.
 func (v Value) Invoke(args ...interface{}) Value {
 	res, ok := valueInvoke(v.ref, makeArgs(args))
 	if !ok {
@@ -287,6 +289,7 @@ func valueInvoke(v ref, args []ref) (ref, bool)
 
 // New uses JavaScript's "new" operator with value v as constructor and the given arguments.
 // It panics if v is not a function.
+// The arguments get mapped to JavaScript values according to the ValueOf function.
 func (v Value) New(args ...interface{}) Value {
 	res, ok := valueNew(v.ref, makeArgs(args))
 	if !ok {

src/syscall/js/typedarray.go

@@ -41,7 +41,6 @@ var (
 )
 
 // TypedArrayOf returns a JavaScript typed array backed by the slice's underlying array.
-// It can be passed to functions of this package that accept interface{}, for example Value.Set and Value.Call.
 //
 // The supported types are []int8, []int16, []int32, []uint8, []uint16, []uint32, []float32 and []float64.
 // Passing an unsupported value causes a panic.