add notes to prohibit using values sharing same data for arguments (ref

#188)

README.md

@@ -127,7 +127,7 @@ func main() {
 - Firstly, use [`gojq.Parse(string) (*Query, error)`](https://pkg.go.dev/github.com/itchyny/gojq#Parse) to get the query from a string.
 - Secondly, get the result iterator
   - using [`query.Run`](https://pkg.go.dev/github.com/itchyny/gojq#Query.Run) or [`query.RunWithContext`](https://pkg.go.dev/github.com/itchyny/gojq#Query.RunWithContext)
-  - or alternatively, compile the query using [`gojq.Compile`](https://pkg.go.dev/github.com/itchyny/gojq#Compile) and then [`code.Run`](https://pkg.go.dev/github.com/itchyny/gojq#Code.Run) or [`code.RunWithContext`](https://pkg.go.dev/github.com/itchyny/gojq#Code.RunWithContext). You can reuse the `*Code` against multiple inputs to avoid compilation of the same query.
+  - or alternatively, compile the query using [`gojq.Compile`](https://pkg.go.dev/github.com/itchyny/gojq#Compile) and then [`code.Run`](https://pkg.go.dev/github.com/itchyny/gojq#Code.Run) or [`code.RunWithContext`](https://pkg.go.dev/github.com/itchyny/gojq#Code.RunWithContext). You can reuse the `*Code` against multiple inputs to avoid compilation of the same query. But for arguments of `code.Run`, do not give values sharing same data between multiple calls.
   - In either case, you cannot use custom type values as the query input. The type should be `[]interface{}` for an array and `map[string]interface{}` for a map (just like decoded to an `interface{}` using the [encoding/json](https://golang.org/pkg/encoding/json/) package). You can't use `[]int` or `map[string]string`, for example. If you want to query your custom struct, marshal to JSON, unmarshal to `interface{}` and use it as the query input.
 - Thirdly, iterate through the results using [`iter.Next() (interface{}, bool)`](https://pkg.go.dev/github.com/itchyny/gojq#Iter). The iterator can emit an error so make sure to handle it. The method returns `true` with results, and `false` when the iterator terminates.
   - The return type is not `(interface{}, error)` because iterators can emit multiple errors and you can continue after an error. It is difficult for the iterator to tell the termination in this situation.

compiler.go

@@ -34,6 +34,7 @@ type Code struct {
 // a result iterator.
 //
 // It is safe to call this method in goroutines, to reuse a compiled [*Code].
+// But for arguments, do not give values sharing same data between goroutines.
 func (c *Code) Run(v interface{}, values ...interface{}) Iter {
 	return c.RunWithContext(context.Background(), v, values...)
 }

query.go

@@ -20,6 +20,7 @@ type Query struct {
 // Run the query.
 //
 // It is safe to call this method in goroutines, to reuse a parsed [*Query].
+// But for arguments, do not give values sharing same data between goroutines.
 func (e *Query) Run(v interface{}) Iter {
 	return e.RunWithContext(context.Background(), v)
 }