rearrange builtins

object/hash.go

@@ -0,0 +1,91 @@
+package object
+
+import (
+	"bytes"
+	"fmt"
+	"hash/fnv"
+	"strings"
+)
+
+type HashKey struct {
+	Type  ObjectType
+	Value uint64
+}
+
+func (b *Boolean) HashKey() HashKey {
+	var value uint64
+
+	if b.Value {
+		value = 1
+	} else {
+		value = 0
+	}
+
+	return HashKey{Type: b.Type(), Value: value}
+}
+
+func (i *Integer) HashKey() HashKey {
+	return HashKey{Type: i.Type(), Value: uint64(i.Value)}
+}
+
+func (s *String) HashKey() HashKey {
+	h := fnv.New64a()
+	h.Write([]byte(s.Value))
+
+	return HashKey{Type: s.Type(), Value: h.Sum64()}
+}
+
+type HashPair struct {
+	Key   Object
+	Value Object
+}
+
+type Hash struct {
+	Pairs map[HashKey]HashPair
+}
+
+func (h *Hash) Type() ObjectType {
+	return HASH_OBJ
+}
+func (h *Hash) Inspect() string {
+	var out bytes.Buffer
+
+	pairs := []string{}
+	for _, pair := range h.Pairs {
+		pairs = append(pairs, fmt.Sprintf("%s: %s", pair.Key.Inspect(), pair.Value.Inspect()))
+	}
+
+	out.WriteString("{")
+	out.WriteString(strings.Join(pairs, ", "))
+	out.WriteString("}")
+
+	return out.String()
+}
+func (h *Hash) String() string {
+	return h.Inspect()
+}
+func (h *Hash) Equal(other Object) bool {
+	if obj, ok := other.(*Hash); ok {
+		if len(h.Pairs) != len(obj.Pairs) {
+			return false
+		}
+		for _, pair := range h.Pairs {
+			left := pair.Value
+			hashed := left.(Hashable)
+			right, ok := obj.Pairs[hashed.HashKey()]
+			if !ok {
+				return false
+			}
+			cmp, ok := left.(Comparable)
+			if !ok {
+				return false
+			}
+			if !cmp.Equal(right.Value) {
+				return false
+			}
+		}
+
+		return true
+	}
+	return false
+}