Basic helper to stream a json array

Uses regular decode to decode actual object data for items in the array.

src/cmd/jsondebug/decoder/decoder.go

@@ -0,0 +1,51 @@
+package decoder
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/alcionai/clues"
+)
+
+const (
+	arrayOpen  = "["
+	arrayClose = "]"
+)
+
+func DecodeArray[T any](r io.Reader, output *[]T) error {
+	dec := json.NewDecoder(r)
+	arrayStarted := false
+
+	for {
+		t, err := dec.Token()
+		if err == io.EOF {
+			// Done processing input.
+			break
+		} else if err != nil {
+			return clues.Wrap(err, "reading JSON token")
+		}
+
+		d, ok := t.(json.Delim)
+		if !ok {
+			return clues.New(fmt.Sprintf("unexpected token: (%T) %v", t, t))
+		} else if arrayStarted && d.String() == arrayClose {
+			break
+		} else if d.String() != arrayOpen {
+			return clues.New(fmt.Sprintf("expected array start but found %s", d))
+		}
+
+		arrayStarted = true
+
+		for dec.More() {
+			tmp := *new(T)
+			if err := dec.Decode(&tmp); err != nil {
+				return clues.Wrap(err, "decoding array element")
+			}
+
+			*output = append(*output, tmp)
+		}
+	}
+
+	return nil
+}