generate: Alter protocol parsing to support HOPP features

generate/generate.go

@@ -1,4 +1,4 @@
-package generate
+package protocol
 
 // Generate turns this protocol into code.
 func (this *Protocol) Generate(writer io.Writer) error {

generate/protocol.go

@@ -2,8 +2,8 @@ package protocol
 
 import "io"
 import "fmt"
-import "bytes"
 import "errors"
+import "strconv"
 import "strings"
 import "github.com/gomarkdown/markdown"
 import "github.com/gomarkdown/markdown/ast"
@@ -16,21 +16,23 @@ type Protocol struct {
 
 // Message describes a protocol message.
 type Message struct {
-	Doc string
-	Name string
+	Doc    string
+	Method uint16
+	Name   string
 	Fields []Field
 }
 
 // Field describes a named value within a message.
 type Field struct {
 	Doc      string
+	Tag      uint16
 	Name     string
 	Optional bool
 	Type     string
 }
 
 // ParseReader parses a protocol definition from a reader.
-func ParseReader (reader io.Reader) (*Protocol, error) {
+func ParseReader(reader io.Reader) (*Protocol, error) {
 	data, err := io.ReadAll(reader)
 	if err != nil { return nil, err }
 	protocol := new(Protocol)
@@ -40,7 +42,7 @@ func ParseReader (reader io.Reader) (*Protocol, error) {
 }
 
 // UnmarshalText unmarshals markdown-formatted text data into the protocol.
-func (this *Protocol) UnmarshalText (text []byte) error {
+func (this *Protocol) UnmarshalText(text []byte) error {
 	var state int; const (
 		stateIdle = iota
 		stateMessage
@@ -49,9 +51,10 @@ func (this *Protocol) UnmarshalText (text []byte) error {
 	)
 
 	var message *Message
-	addMessage := func (name string) {
+	addMessage := func(method uint16, name string) {
 		this.Messages = append(this.Messages, Message {
-			Name: name,
+			Method: method,
+			Name:   name,
 		})
 		message = &this.Messages[len(this.Messages) - 1]
 	}
@@ -72,7 +75,10 @@ func (this *Protocol) UnmarshalText (text []byte) error {
 			}
 
 			if state != stateIdle && node.Level == 3 {
-				addMessage(removeBreaks(flatten(node)))
+				heading := removeBreaks(flatten(node))
+				method, name, err := splitMessageHeading(heading)
+				if err != nil { return err }
+				addMessage(method, name)
 				state = stateMessageDoc
 			}
 		}
@@ -80,6 +86,9 @@ func (this *Protocol) UnmarshalText (text []byte) error {
 		if state == stateIdle { continue }
 		if message == nil     { continue }
 
+		// TODO when we are adding text content to the doc comment, it
+		// might be wise to do stuff like indent lists and quotes so
+		// that go doc renders them correctly
 		switch node := node.(type) {
 		case *ast.Paragraph:
 			if message.Doc != "" { message.Doc += "\n\n" }
@@ -88,9 +97,9 @@ func (this *Protocol) UnmarshalText (text []byte) error {
 			if message.Doc != "" { message.Doc += "\n\n> " }
 			message.Doc += removeBreaks(flatten(node))
 		case *ast.List:
-			fields, err := processFieldList(node)
-			if err != nil { return err}
-			message.Fields = append(message.Fields, fields...)
+			// FIXME format the list
+			if message.Doc != "" { message.Doc += "\n\n" }
+			message.Doc += removeBreaks(flatten(node))
 		case *ast.Table:
 			fields, err := processFieldTable(node)
 			if err != nil { return err}
@@ -101,49 +110,7 @@ func (this *Protocol) UnmarshalText (text []byte) error {
 	return nil
 }
 
-func (this *Protocol) MarshalText () ([]byte, error) {
-	buffer := bytes.NewBuffer(nil)
-
-	fmt.Fprint(buffer, "# Messages\n")
-	for index, message := range this.Messages {
-		if index > 0 {
-			fmt.Fprint(buffer, "\n")
-		}
-		fmt.Fprintf(buffer, "## %s\n", message.Name)
-		if message.Doc != "" {
-			fmt.Fprintf(buffer, "%s\n", message.Doc)
-		}
-		if len(message.Fields) > 0 {
-			fmt.Fprint(buffer, "\n")
-		}
-		for _, field := range message.Fields {
-			fmt.Fprintf(buffer, "- %s", field.Name)
-			if field.Type != "" {
-				fmt.Fprintf(buffer, " %s", field.Type)
-			}
-			if field.Doc != "" {
-				fmt.Fprintf(buffer, ": %s", field.Doc)
-			}
-			fmt.Fprint(buffer, "\n")
-		}
-	}
-	
-	return buffer.Bytes(), nil
-}
-
-func processFieldList (node *ast.List) ([]Field, error) {
-	fields := []Field { }
-	for _, item := range node.GetChildren() {
-		if item, ok := item.(*ast.ListItem); ok {
-			field, err := processFieldListItem(removeBreaks(flatten(item)))
-			if err != nil { return nil, err }
-			fields = append(fields, field)
-		}
-	}
-	return fields, nil
-}
-
-func processFieldTable (node *ast.Table) ([]Field, error) {
+func processFieldTable(node *ast.Table) ([]Field, error) {
 	fields := []Field { }
 	children := node.GetChildren()
 	if len(children) != 2 {
@@ -190,6 +157,10 @@ func processFieldTable (node *ast.Table) ([]Field, error) {
 			if cell, ok := node.(*ast.TableCell); ok {
 				text := flatten(cell)
 				switch columns[index] {
+				case "tag":
+					tag, err := parseTag(text)
+					if err != nil { return nil, err }
+					field.Tag = tag
 				case "name":
 					field.Name = text
 				case "required":
@@ -214,8 +185,8 @@ func processFieldTable (node *ast.Table) ([]Field, error) {
 type nodeFlattener struct {
 	text string
 }
-func (this *nodeFlattener) String () string { return this.text }
-func (this *nodeFlattener) Visit (node ast.Node, entering bool) ast.WalkStatus {
+func (this *nodeFlattener) String() string { return this.text }
+func (this *nodeFlattener) Visit(node ast.Node, entering bool) ast.WalkStatus {
 	if entering {
 		if node := node.AsLeaf(); node != nil {
 			this.text += string(node.Literal)
@@ -223,35 +194,20 @@ func (this *nodeFlattener) Visit (node ast.Node, entering bool) ast.WalkStatus {
 	}
 	return ast.GoToNext
 }
-func flatten (node ast.Node) string {
+func flatten(node ast.Node) string {
 	flattener := new(nodeFlattener)
 	ast.Walk(node, flattener)
 	return flattener.text
 }
 
-func processFieldListItem (bullet string) (Field, error) {
-	field := Field { }
-	nameAndType, doc, hasDoc := strings.Cut(bullet, ":")
-	if hasDoc {
-		field.Doc = strings.TrimSpace(doc)
-	}
 
-	name, ty, hasType := strings.Cut(strings.TrimSpace(nameAndType), " ")
-	if !hasType {
-		return Field { }, errors.New(fmt.Sprintf("unspecified type near '%s'", bullet))
-	}
-	field.Name = strings.TrimSpace(name)
-	field.Type = strings.TrimSpace(ty)
-	return field, nil
-}
-
-func removeBreaks (text string) string {
+func removeBreaks(text string) string {
 	text = strings.ReplaceAll(text, "\n", " ")
 	text = strings.ReplaceAll(text, "\r", "")
 	return text
 }
 
-func parseBool (text string) bool {
+func parseBool(text string) bool {
 	switch(strings.ToLower(text)) {
 	case "yes": return true
 	case "no": return false
@@ -260,3 +216,35 @@ func parseBool (text string) bool {
 	}
 	return false
 }
+
+func parseTag(text string) (uint16, error) {
+	tag, err := strconv.ParseUint(text, 10, 16)
+	if err != nil {
+		return 0, fmt.Errorf("malformed tag '%s': %w", text, err)
+	}
+	return uint16(tag), nil
+}
+
+func splitMessageHeading(text string) (uint16, string, error) {
+	text = strings.TrimSpace(text)
+	if !strings.HasPrefix(text, "(") {
+		return 0, "", fmt.Errorf(
+			"malformed message heading '%s': no method number",
+			text)
+	}
+	text = strings.TrimPrefix(text, "(")
+	methodText, name, ok := strings.Cut(text, ")")
+	if !ok {
+		return 0, "", fmt.Errorf(
+			"malformed message heading '%s': no message name",
+			text)
+	}
+	method, err := strconv.ParseUint(text, 10, 16)
+	if err != nil {
+		return 0, "", fmt.Errorf(
+			"malformed method number '%s': %w",
+			methodText, err)
+	}
+	name = strings.TrimSpace(text)
+	return uint16(method), name, nil
+}