1 files changed, 75 insertions, 0 deletions
diff --git a/demux.go b/demux.go
new file mode 100644
index 0000000..632630d
--- /dev/null
+++ b/demux.go
@@ -0,0 +1,75 @@
+package binproto
+
+type urReturn struct {
+	ut   UnitType
+	data interface{}
+}
+
+type Demux struct {
+	ur            UnitReader
+	events, other chan urReturn
+	err           error
+}
+
+func NewDemux(ur UnitReader) (d *Demux) {
+	d = &Demux{
+		ur:     ur,
+		events: make(chan urReturn),
+		other:  make(chan urReturn),
+		err:    nil}
+	go d.demux()
+	return
+}
+
+func (d *Demux) demux() {
+	inEvent := false
+	nesting := 0
+
+	for {
+		ut, data, err := d.ur.ReadUnit()
+		if err != nil {
+			d.err = err
+			close(d.events)
+			close(d.other)
+			return
+		}
+
+		if inEvent {
+			switch ut {
+			case UTList, UTIdKVMap, UTTextKVMap:
+				nesting++
+			case UTTerm:
+				nesting--
+			}
+
+			d.events <- urReturn{ut, data}
+
+			if nesting <= 0 {
+				inEvent = false
+			}
+		} else if ut == UTEvent {
+			d.events <- urReturn{ut, data}
+			inEvent = true
+			nesting = 0
+		} else {
+			d.other <- urReturn{ut, data}
+		}
+	}
+}
+
+type PartUnitReader struct {
+	ch chan urReturn
+	d  *Demux
+}
+
+func (d *Demux) Events() *PartUnitReader { return &PartUnitReader{d.events, d} }
+func (d *Demux) Other() *PartUnitReader  { return &PartUnitReader{d.other, d} }
+
+func (pur *PartUnitReader) ReadUnit() (UnitType, interface{}, error) {
+	urr, ok := <-pur.ch
+	if !ok {
+		return 0, nil, pur.d.err
+	}
+
+	return urr.ut, urr.data, nil
+}