readability

main.go

@@ -46,7 +46,7 @@ func reader(in string) (io.Reader, error) {
 	if in != "" {
 		file, err := os.Open(in)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("reader: %w", err)
 		}
 
 		return file, nil
@@ -59,7 +59,7 @@ func writer(out string) (io.Writer, error) {
 	if out != "" {
 		file, err := os.Create(out)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("writer: %w", err)
 		}
 
 		return file, nil
@@ -76,14 +76,17 @@ func source(r io.Reader) pipe.Source {
 	return func() chan pipe.StreamItem {
 		data := make(chan pipe.StreamItem)
 		s := bufio.NewScanner(r)
+
 		go func() {
 			i := 0
+
 			for s.Scan() {
 				data <- pipe.NewItem(i, s.Bytes())
-				i += 1
+				i++
 			}
 			close(data)
 		}()
+
 		return data
 	}
 }
@@ -115,11 +118,8 @@ func main() {
 		os.Exit(1)
 	}
 
-	preproc := NewPreproc()
-
-	//sink.Input(preproc.Process(source.Output()))
 	s := pipe.New()
-	s.Use(preproc.Process)
+	s.Use(newPreproc().Process)
 	s.Use(RemoveFrontMatter)
 	s.Use(RemoveComments)
 	s.Use(FormatHeadings)

pipe/pipe.go

@@ -12,12 +12,16 @@ type StreamItem struct {
 
 func NewItem(index int, payload []byte) StreamItem {
 	var buf bytes.Buffer
+
 	w := StreamItem{index: index}
+
 	if err := gob.NewEncoder(&buf).Encode(payload); err != nil {
 		// assert no broken pipes
 		panic(err)
 	}
+
 	w.payload = buf.Bytes()
+
 	return w
 }
 
@@ -27,7 +31,9 @@ func (w *StreamItem) Index() int {
 
 func (w *StreamItem) Payload() []byte {
 	var dec []byte
+
 	buf := bytes.NewReader(w.payload)
+
 	if err := gob.NewDecoder(buf).Decode(&dec); err != nil {
 		// assert no broken pipes
 		panic(err)

pipe/stream.go

@@ -26,6 +26,7 @@ func chain(nodes []Pipeline, src Connector) Connector {
 	for i := 1; i < len(nodes); i++ {
 		c = nodes[i](c)
 	}
+
 	return c
 }
 

preproc.go

@@ -7,10 +7,10 @@ import (
 	"github.com/n0x1m/md2gmi/pipe"
 )
 
-// state function
+// state function.
 type stateFn func(*fsm, []byte) stateFn
 
-// state machine
+// state machine.
 type fsm struct {
 	state stateFn
 
@@ -24,12 +24,13 @@ type fsm struct {
 	pending []byte
 }
 
-func NewPreproc() *fsm {
+func newPreproc() *fsm {
 	return &fsm{}
 }
 
 func (m *fsm) Process(in chan pipe.StreamItem) chan pipe.StreamItem {
 	m.out = make(chan pipe.StreamItem)
+
 	go func() {
 		for m.state = normal; m.state != nil; {
 			b, ok := <-in
@@ -38,6 +39,7 @@ func (m *fsm) Process(in chan pipe.StreamItem) chan pipe.StreamItem {
 				m.sync()
 				close(m.out)
 				m.state = nil
+
 				continue
 			}
 
@@ -45,6 +47,7 @@ func (m *fsm) Process(in chan pipe.StreamItem) chan pipe.StreamItem {
 			m.sync()
 		}
 	}()
+
 	return m.out
 }
 
@@ -53,7 +56,7 @@ func (m *fsm) sync() {
 		m.sendBuffer = append(m.sendBuffer, '\n')
 		m.out <- pipe.NewItem(m.i, m.sendBuffer)
 		m.sendBuffer = m.sendBuffer[:0]
-		m.i += 1
+		m.i++
 	}
 }
 
@@ -84,6 +87,7 @@ func handleList(data []byte) ([]byte, bool) {
 	if len(sub) > 1 {
 		return bytes.Replace(data, sub[1], []byte("-"), 1), true
 	}
+
 	return data, false
 }
 
@@ -99,27 +103,34 @@ func normal(m *fsm, data []byte) stateFn {
 	if data, isList := handleList(data); isList {
 		m.blockBuffer = append(data, '\n')
 		m.blockFlush()
+
 		return normal
 	}
+
 	if isFence(data) {
 		m.blockBuffer = append(data, '\n')
+
 		return fence
 	}
+
 	if needsFence(data) {
 		m.blockBuffer = append(m.blockBuffer, []byte("```\n")...)
 		m.blockBuffer = append(m.blockBuffer, append(data[4:], '\n')...)
 		m.pending = []byte("```\n")
+
 		return toFence
 	}
+
 	if isTerminated(data) {
 		m.blockBuffer = append(m.blockBuffer, data...)
 		m.blockBuffer = append(m.blockBuffer, ' ')
+
 		return paragraph
 	}
-	// TODO
-	// collapse lists
+
 	m.blockBuffer = append(m.blockBuffer, append(data, '\n')...)
 	m.blockFlush()
+
 	return normal
 }
 
@@ -128,18 +139,23 @@ func fence(m *fsm, data []byte) stateFn {
 	// second fence returns to normal
 	if isFence(data) {
 		m.blockFlush()
+
 		return normal
 	}
+
 	return fence
 }
 
 func toFence(m *fsm, data []byte) stateFn {
 	if needsFence(data) {
 		m.blockBuffer = append(m.blockBuffer, append(data[4:], '\n')...)
+
 		return toFence
 	}
+
 	m.blockFlush()
 	m.blockBuffer = append(m.blockBuffer, append(data, '\n')...)
+
 	return normal
 }
 
@@ -149,9 +165,12 @@ func paragraph(m *fsm, data []byte) stateFn {
 		m.blockBuffer = bytes.TrimSpace(m.blockBuffer)
 		m.blockBuffer = append(m.blockBuffer, '\n')
 		m.blockFlush()
+
 		return normal
 	}
+
 	m.blockBuffer = append(m.blockBuffer, data...)
 	m.blockBuffer = append(m.blockBuffer, []byte(" ")...)
+
 	return paragraph
 }

proc.go

@@ -10,28 +10,36 @@ import (
 
 func FormatLinks(in chan pipe.StreamItem) chan pipe.StreamItem {
 	out := make(chan pipe.StreamItem)
+
 	go func() {
 		fenceOn := false
+
 		for b := range in {
 			data := b.Payload()
 			if isFence(data) {
 				fenceOn = !fenceOn
 			}
+
 			if fenceOn {
 				out <- pipe.NewItem(b.Index(), b.Payload())
-			} else {
-				out <- pipe.NewItem(b.Index(), formatLinks(b.Payload()))
+
+				continue
 			}
+			out <- pipe.NewItem(b.Index(), formatLinks(b.Payload()))
 		}
+
 		close(out)
 	}()
+
 	return out
 }
 
 func formatLinks(data []byte) []byte {
 	// find link name and url
 	var buffer []byte
+
 	re := regexp.MustCompile(`!?\[([^\]*]*)\]\(([^)]*)\)`)
+
 	for i, match := range re.FindAllSubmatch(data, -1) {
 		replaceWithIndex := append(match[1], fmt.Sprintf("[%d]", i+1)...)
 		data = bytes.Replace(data, match[0], replaceWithIndex, 1)
@@ -50,43 +58,51 @@ func formatLinks(data []byte) []byte {
 
 func RemoveComments(in chan pipe.StreamItem) chan pipe.StreamItem {
 	out := make(chan pipe.StreamItem)
+
 	go func() {
 		re := regexp.MustCompile(`<!--.*-->`)
+
 		for b := range in {
 			data := b.Payload()
 			for _, match := range re.FindAllSubmatch(data, -1) {
 				data = bytes.Replace(data, match[0], []byte(""), 1)
 			}
 			out <- pipe.NewItem(b.Index(), append(bytes.TrimSpace(data), '\n'))
-			//out <- pipe.NewItem(b.Index(), data)
 		}
+
 		close(out)
 	}()
+
 	return out
 }
 
 func RemoveFrontMatter(in chan pipe.StreamItem) chan pipe.StreamItem {
 	out := make(chan pipe.StreamItem)
+
 	go func() {
 		re := regexp.MustCompile(`---.*---`)
+
 		for b := range in {
 			data := b.Payload()
 			for _, match := range re.FindAllSubmatch(data, -1) {
 				data = bytes.Replace(data, match[0], []byte(""), 1)
 			}
 			out <- pipe.NewItem(b.Index(), append(bytes.TrimSpace(data), '\n'))
-			//out <- pipe.NewItem(b.Index(), data)
 		}
+
 		close(out)
 	}()
+
 	return out
 }
 
 func FormatHeadings(in chan pipe.StreamItem) chan pipe.StreamItem {
 	out := make(chan pipe.StreamItem)
+
 	go func() {
 		re := regexp.MustCompile(`^[#]{4,}`)
 		re2 := regexp.MustCompile(`^(#+)[^# ]`)
+
 		for b := range in {
 			// fix up more than 4 levels
 			data := re.ReplaceAll(b.Payload(), []byte("###"))
@@ -101,9 +117,10 @@ func FormatHeadings(in chan pipe.StreamItem) chan pipe.StreamItem {
 			}
 			// writeback
 			out <- pipe.NewItem(b.Index(), data)
-
 		}
+
 		close(out)
 	}()
+
 	return out
 }