add vendor data

vendor/github.com/dunglas/httpsfv/encode.go

@@ -0,0 +1,42 @@
+// Package httpsfv implements serializing and parsing
+// of Structured Field Values for HTTP as defined in RFC 9651.
+//
+// Structured Field Values are either lists, dictionaries or items. Dedicated types are provided for all of them.
+// Dedicated types are also used for tokens, parameters and inner lists.
+// Other values are stored in native types:
+//
+//	int64, for integers
+//	float64, for decimals
+//	string, for strings
+//	byte[], for byte sequences
+//	bool, for booleans
+//
+// The specification is available at https://httpwg.org/specs/rfc9651.html.
+package httpsfv
+
+import (
+	"strings"
+)
+
+// marshaler is the interface implemented by types that can marshal themselves into valid SFV.
+type marshaler interface {
+	marshalSFV(b *strings.Builder) error
+}
+
+// StructuredFieldValue represents a List, a Dictionary or an Item.
+type StructuredFieldValue interface {
+	marshaler
+}
+
+// Marshal returns the HTTP Structured Value serialization of v
+// as defined in https://httpwg.org/specs/rfc9651.html#text-serialize.
+//
+// v must be a List, a Dictionary, an Item or an InnerList.
+func Marshal(v StructuredFieldValue) (string, error) {
+	var b strings.Builder
+	if err := v.marshalSFV(&b); err != nil {
+		return "", err
+	}
+
+	return b.String(), nil
+}