From 47e056f253fdefc244380529ab5990cff890ddad Mon Sep 17 00:00:00 2001
From: Timur Demin <me@tdem.in>
Date: Sat, 12 Dec 2020 14:03:29 +0500
Subject: [PATCH] Refactor RenderMarkdown signature

This makes the function accept a bitmask instead of a single flag. This
is a breaking change.
---
 cmd/gmnhg/main.go |  8 +++-----
 render.go         | 23 ++++++++++++++---------
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/cmd/gmnhg/main.go b/cmd/gmnhg/main.go
index 0f51589..170c991 100644
--- a/cmd/gmnhg/main.go
+++ b/cmd/gmnhg/main.go
@@ -98,8 +98,6 @@ var (
 	topLevelPostRegex = regexp.MustCompile(contentBase + `([\w-_ ]+)/([\w-_ ]+)\.md`)
 )
 
-// TODO: more meaningful errors
-
 type post struct {
 	Post     []byte
 	Metadata gemini.HugoMetadata
@@ -205,7 +203,7 @@ func main() {
 		if err != nil {
 			return err
 		}
-		gemText, metadata, err := gemini.RenderMarkdown(fileContent, gemini.WithoutMetadata)
+		gemText, metadata, err := gemini.RenderMarkdown(fileContent, gemini.Defaults)
 		// skip drafts from rendering
 		if errors.Is(err, gemini.ErrPostIsDraft) {
 			return nil
@@ -277,7 +275,7 @@ func main() {
 			// skip unreadable index files
 			continue
 		}
-		gemtext, _, err := gemini.RenderMarkdown(content, gemini.WithoutMetadata)
+		gemtext, _, err := gemini.RenderMarkdown(content, gemini.Defaults)
 		if errors.Is(err, gemini.ErrPostIsDraft) {
 			continue
 		} else if err != nil {
@@ -305,7 +303,7 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	gemtext, _, err := gemini.RenderMarkdown(indexContent, gemini.WithoutMetadata)
+	gemtext, _, err := gemini.RenderMarkdown(indexContent, gemini.Defaults)
 	if err != nil && !errors.Is(err, gemini.ErrPostIsDraft) {
 		panic(err)
 	}
diff --git a/render.go b/render.go
index bd07869..7008316 100644
--- a/render.go
+++ b/render.go
@@ -54,15 +54,20 @@ var yamlDelimiter = []byte("---\n")
 // supposed to be rendered.
 var ErrPostIsDraft = errors.New("post is draft")
 
-// MetadataSetting defines whether or not metadata is included in the
-// rendered text.
-type MetadataSetting int
+// Settings is a bitmask for renderer preferences.
+type Settings uint
+
+// Has uses AND to check whether a flag is set.
+func (s Settings) Has(setting Settings) bool {
+	return (s & setting) != 0
+}
 
-// Metadata settings control the inclusion of metadata in the rendered
-// text.
 const (
-	WithMetadata MetadataSetting = iota
-	WithoutMetadata
+	// Defaults simply renders the document.
+	Defaults Settings = 0b0
+	// WithMetadata indicates that the metadata should be included in
+	// the text produced by the renderer.
+	WithMetadata Settings = 0b1
 )
 
 // RenderMarkdown converts Markdown text to text/gemini using
@@ -74,7 +79,7 @@ const (
 //
 // Draft posts are still rendered, but with an error of type
 // ErrPostIsDraft.
-func RenderMarkdown(md []byte, metadataSetting MetadataSetting) (geminiText []byte, metadata HugoMetadata, err error) {
+func RenderMarkdown(md []byte, settings Settings) (geminiText []byte, metadata HugoMetadata, err error) {
 	var (
 		blockEnd    int
 		yamlContent []byte
@@ -95,7 +100,7 @@ func RenderMarkdown(md []byte, metadataSetting MetadataSetting) (geminiText []by
 parse:
 	ast := markdown.Parse(md, parser.NewWithExtensions(parser.CommonExtensions))
 	var geminiContent []byte
-	if metadataSetting == WithMetadata && metadata.PostTitle != "" {
+	if settings.Has(WithMetadata) && metadata.PostTitle != "" {
 		geminiContent = markdown.Render(ast, gemini.NewRendererWithMetadata(metadata))
 	} else {
 		geminiContent = markdown.Render(ast, gemini.NewRenderer())