add vendor

vendor/github.com/zclconf/go-cty/cty/set/gob.go

@@ -0,0 +1,76 @@
+package set
+
+import (
+	"bytes"
+	"encoding/gob"
+	"fmt"
+)
+
+// GobEncode is an implementation of the interface gob.GobEncoder, allowing
+// sets to be included in structures encoded via gob.
+//
+// The set rules are included in the serialized value, so the caller must
+// register its concrete rules type with gob.Register before using a
+// set in a gob, and possibly also implement GobEncode/GobDecode to customize
+// how any parameters are persisted.
+//
+// The set elements are also included, so if they are of non-primitive types
+// they too must be registered with gob.
+//
+// If the produced gob values will persist for a long time, the caller must
+// ensure compatibility of the rules implementation. In particular, if the
+// definition of element equivalence changes between encoding and decoding
+// then two distinct stored elements may be considered equivalent on decoding,
+// causing the recovered set to have fewer elements than when it was stored.
+func (s Set) GobEncode() ([]byte, error) {
+	gs := gobSet{
+		Version: 0,
+		Rules:   s.rules,
+		Values:  s.Values(),
+	}
+
+	buf := &bytes.Buffer{}
+	enc := gob.NewEncoder(buf)
+	err := enc.Encode(gs)
+	if err != nil {
+		return nil, fmt.Errorf("error encoding set.Set: %s", err)
+	}
+
+	return buf.Bytes(), nil
+}
+
+// GobDecode is the opposite of GobEncode. See GobEncode for information
+// on the requirements for and caveats of including set values in gobs.
+func (s *Set) GobDecode(buf []byte) error {
+	r := bytes.NewReader(buf)
+	dec := gob.NewDecoder(r)
+
+	var gs gobSet
+	err := dec.Decode(&gs)
+	if err != nil {
+		return fmt.Errorf("error decoding set.Set: %s", err)
+	}
+	if gs.Version != 0 {
+		return fmt.Errorf("unsupported set.Set encoding version %d; need 0", gs.Version)
+	}
+
+	victim := NewSetFromSlice(gs.Rules, gs.Values)
+	s.vals = victim.vals
+	s.rules = victim.rules
+	return nil
+}
+
+type gobSet struct {
+	Version int
+	Rules   Rules
+
+	// The bucket-based representation is for efficient in-memory access, but
+	// for serialization it's enough to just retain the values themselves,
+	// which we can re-bucket using the rules (which may have changed!) when
+	// we re-inflate.
+	Values []interface{}
+}
+
+func init() {
+	gob.Register([]interface{}(nil))
+}