start state machine parser

main.go

@@ -53,14 +53,7 @@ func write(out string, data <-chan []byte, quit chan struct{}) error {
 
 	NewParser(data, w, quit).Parse()
 
-	for {
-		select {
-		case <-quit:
-			return nil
-		case b := <-data:
-			fmt.Fprintf(w, string(b)+"\n")
-		}
-	}
+	return nil
 }
 
 func main() {

parser.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"io"
+)
+
+// state function
+type stateFn func(*fsm, []byte) stateFn
+
+// state machine
+type fsm struct {
+	state stateFn
+	out   io.Writer
+	quit  chan struct{}
+	data  <-chan []byte
+}
+
+func NewParser(data <-chan []byte, writer io.Writer, quit chan struct{}) *fsm {
+	return &fsm{
+		out:  writer,
+		data: data,
+		quit: quit,
+	}
+}
+
+func (m *fsm) Parse() {
+	var buffer []byte
+	for m.state = initial; m.state != nil; {
+		select {
+		case <-m.quit:
+			m.state = nil
+		case buffer = <-m.data:
+			m.state = m.state(m, buffer)
+		}
+	}
+}
+
+func initial(m *fsm, data []byte) stateFn {
+	// TODO
+	// find linebreaks
+	// find code fences
+	// find links
+	// collapse lists
+	fmt.Fprintf(m.out, string(data)+"\n")
+
+	return initial
+}