diff --git a/datagram.go b/datagram.go
new file mode 100644
index 0000000..2342616
--- /dev/null
+++ b/datagram.go
@@ -0,0 +1,72 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/jordanorelli/hyperstone/bit"
+	"github.com/jordanorelli/hyperstone/dota"
+)
+
+// datagram represents the top-level envelope in the dota replay format. All
+// data in the replay file is packed into datagram frames of at most 65kb.
+type dataGram struct {
+	cmd        dota.EDemoCommands
+	tick       int64
+	compressed bool
+	body       []byte
+}
+
+func (g dataGram) String() string {
+	if len(g.body) > 30 {
+		return fmt.Sprintf("{dataGram cmd: %v tick: %v compressed: %t size: %d body: %q...}", g.cmd, g.tick, g.compressed, len(g.body), g.body[:27])
+	}
+	return fmt.Sprintf("{dataGram cmd: %v tick: %v compressed: %t size: %d body: %q}", g.cmd, g.tick, g.compressed, len(g.body), g.body)
+}
+
+func (g *dataGram) check(dump bool) error {
+	if g.cmd != dota.EDemoCommands_DEM_Packet {
+		return fmt.Errorf("wrong command type in openPacket: %v", g.cmd)
+	}
+
+	if g.compressed {
+		buf, err := snappy.Decode(nil, g.body)
+		if err != nil {
+			return wrap(err, "open packet error: could not decode body")
+		}
+		g.body = buf
+		g.compressed = false
+	}
+
+	packet := new(dota.CDemoPacket)
+	if err := proto.Unmarshal(g.body, packet); err != nil {
+		return wrap(err, "onPacket unable to unmarshal message body")
+	}
+
+	if dump {
+		br := bit.NewBytesReader(packet.GetData())
+		for {
+			t := br.ReadUBitVar()
+			s := br.ReadVarInt()
+			b := make([]byte, s)
+			br.Read(b)
+			if br.Err() != nil {
+				break
+			}
+			fmt.Printf("\t%v\n", entity{t: uint32(t), size: uint32(s), body: b})
+			e := entFactory.BuildMessage(int(t))
+			if e == nil {
+				fmt.Printf("\tno known entity for type id %d\n", int(t))
+				continue
+			}
+			err := proto.Unmarshal(b, e)
+			if err != nil {
+				fmt.Printf("entity unmarshal error: %v\n", err)
+			} else {
+				fmt.Printf("\t\t%v\n", e)
+			}
+		}
+	}
+	return nil
+}
diff --git a/entity.go b/entity.go
new file mode 100644
index 0000000..fb76cf1
--- /dev/null
+++ b/entity.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+)
+
+type entity struct {
+	t    uint32
+	size uint32
+	body []byte
+}
+
+func (e entity) String() string {
+	if len(e.body) < 32 {
+		return fmt.Sprintf("{entity type: %d size: %d data: %x}", e.t, e.size, e.body)
+	}
+	return fmt.Sprintf("{entity type: %d size: %d data: %x...}", e.t, e.size, e.body[:32])
+}
diff --git a/message.go b/message.go
deleted file mode 100644
index 7c17211..0000000
--- a/message.go
+++ /dev/null
@@ -1,86 +0,0 @@
-package main
-
-import (
-	"fmt"
-
-	"github.com/golang/protobuf/proto"
-	"github.com/golang/snappy"
-	"github.com/jordanorelli/hyperstone/bit"
-	"github.com/jordanorelli/hyperstone/dota"
-)
-
-// message represents the top-level envelope in the dota replay format. Each
-// datum is contained within a message envelope. Each message envelope is at
-// most 1<<16 bytes.
-type message struct {
-	cmd        dota.EDemoCommands
-	tick       int64
-	compressed bool
-	body       []byte
-}
-
-func (m message) String() string {
-	if len(m.body) > 30 {
-		return fmt.Sprintf("{cmd: %v tick: %v compressed: %t size: %d body: %q...}", m.cmd, m.tick, m.compressed, len(m.body), m.body[:27])
-	}
-	return fmt.Sprintf("{cmd: %v tick: %v compressed: %t size: %d body: %q}", m.cmd, m.tick, m.compressed, len(m.body), m.body)
-}
-
-type entity struct {
-	t    uint32
-	size uint32
-	body []byte
-}
-
-func (e entity) String() string {
-	if len(e.body) < 32 {
-		return fmt.Sprintf("{%v %v %x}", e.t, e.size, e.body)
-	}
-	return fmt.Sprintf("{%v %v %x...}", e.t, e.size, e.body[:32])
-}
-
-func (m *message) check(dump bool) error {
-	if m.cmd != dota.EDemoCommands_DEM_Packet {
-		return fmt.Errorf("wrong command type in openPacket: %v", m.cmd)
-	}
-
-	if m.compressed {
-		buf, err := snappy.Decode(nil, m.body)
-		if err != nil {
-			return wrap(err, "open packet error: could not decode body")
-		}
-		m.body = buf
-		m.compressed = false
-	}
-
-	packet := new(dota.CDemoPacket)
-	if err := proto.Unmarshal(m.body, packet); err != nil {
-		return wrap(err, "onPacket unable to unmarshal message body")
-	}
-
-	if dump {
-		br := bit.NewBytesReader(packet.GetData())
-		for {
-			t := br.ReadUBitVar()
-			s := br.ReadVarInt()
-			b := make([]byte, s)
-			br.Read(b)
-			if br.Err() != nil {
-				break
-			}
-			fmt.Printf("\t%v\n", entity{t: uint32(t), size: uint32(s), body: b})
-			e := entFactory.BuildMessage(int(t))
-			if e == nil {
-				fmt.Printf("\tno known entity for type id %d\n", int(t))
-				continue
-			}
-			err := proto.Unmarshal(b, e)
-			if err != nil {
-				fmt.Printf("entity unmarshal error: %v\n", err)
-			} else {
-				fmt.Printf("\t\t%v\n", e)
-			}
-		}
-	}
-	return nil
-}
diff --git a/parser.go b/parser.go
index 4106022..f67c264 100644
--- a/parser.go
+++ b/parser.go
@@ -133,7 +133,7 @@ func (p *parser) readCommand() (dota.EDemoCommands, bool, error) {
 	return dota.EDemoCommands(n), compressed, nil
 }
 
-func (p *parser) readMessage() (*message, error) {
+func (p *parser) readMessage() (*dataGram, error) {
 	cmd, compressed, err := p.readCommand()
 	if err != nil {
 		return nil, wrap(err, "readMessage couldn't get a command")
@@ -155,9 +155,9 @@ func (p *parser) readMessage() (*message, error) {
 			return nil, wrap(err, "readMessage couldn't read message body")
 		}
 		// TODO: pool these!
-		return &message{cmd, int64(tick), compressed, buf}, nil
+		return &dataGram{cmd, int64(tick), compressed, buf}, nil
 	}
 
 	// TODO: pool these!
-	return &message{cmd, int64(tick), compressed, nil}, nil
+	return &dataGram{cmd, int64(tick), compressed, nil}, nil
 }