Refactor footnote handling

- Remove unused footnote section title option
- Move away from maintaining a list of footnotes in the document (only needed
  for html export, potential maintainance overhead when modifying the document)
  and rather only build it on export when required.
- HTML export: Rename all footnotes to numbers (so we can support anonymous
  footnote references by assigning them a number) and export footnotes in order
  of reference, not definition. The implementation of this makes it natural to
  also stop exporting unused footnote definitions so we do that as well.

org/document.go

@@ -35,7 +35,6 @@ type Document struct {
 	Path           string // Path of the file containing the parse input - used to resolve relative paths during parsing (e.g. INCLUDE).
 	tokens         []token
 	Nodes          []Node
-	Footnotes      Footnotes
 	Outline        Outline           // Outline is a Table Of Contents for the document and contains all sections (headline + content).
 	BufferSettings map[string]string // Settings contains all settings that were parsed from keywords.
 	Error          error
@@ -113,11 +112,7 @@ func (d *Document) Write(w Writer) (out string, err error) {
 func (c *Configuration) Parse(input io.Reader, path string) (d *Document) {
 	outlineSection := &Section{}
 	d = &Document{
-		Configuration: c,
+		Configuration:  c,
-		Footnotes: Footnotes{
-			Title:       "Footnotes",
-			Definitions: map[string]*FootnoteDefinition{},
-		},
 		Outline:        Outline{outlineSection, outlineSection, 0},
 		BufferSettings: map[string]string{},
 		Path:           path,
@@ -243,16 +238,6 @@ func (d *Document) parseMany(i int, stop stopFn) (int, []Node) {
 	return i - start, nodes
 }
 
-func (d *Document) addFootnote(name string, definition *FootnoteDefinition) {
-	if definition != nil {
-		if _, exists := d.Footnotes.Definitions[name]; exists {
-			d.Log.Printf("Footnote [fn:%s] redefined! %#v", name, definition)
-		}
-		d.Footnotes.Definitions[name] = definition
-	}
-	d.Footnotes.addOrder = append(d.Footnotes.addOrder, name)
-}
-
 func (d *Document) addHeadline(headline *Headline) int {
 	current := &Section{Headline: headline}
 	d.Outline.last.add(current)

org/footnote.go

@@ -4,12 +4,6 @@ import (
 	"regexp"
 )
 
-type Footnotes struct {
-	Title       string
-	Definitions map[string]*FootnoteDefinition
-	addOrder    []string
-}
-
 type FootnoteDefinition struct {
 	Name     string
 	Children []Node
@@ -35,24 +29,7 @@ func (d *Document) parseFootnoteDefinition(i int, parentStop stopFn) (int, Node)
 	}
 	consumed, nodes := d.parseMany(i, stop)
 	definition := FootnoteDefinition{name, nodes, false}
-	d.addFootnote(name, &definition)
 	return consumed, definition
 }
 
-func (fs *Footnotes) Ordered() []FootnoteDefinition {
-	m := map[string]bool{}
-	definitions, inlineDefinitions := []FootnoteDefinition{}, []FootnoteDefinition{}
-	for _, name := range fs.addOrder {
-		if isDuplicate := m[name]; !isDuplicate {
-			m[name] = true
-			if definition := *fs.Definitions[name]; definition.Inline {
-				inlineDefinitions = append(inlineDefinitions, definition)
-			} else {
-				definitions = append(definitions, definition)
-			}
-		}
-	}
-	return append(definitions, inlineDefinitions...)
-}
-
 func (n FootnoteDefinition) String() string { return orgWriter.nodesAsString(n) }

org/html_writer.go

@@ -19,6 +19,12 @@ type HTMLWriter struct {
 	HighlightCodeBlock func(source, lang string) string
 	htmlEscape         bool
 	log                *log.Logger
+	footnotes          footnotes
+}
+
+type footnotes struct {
+	mapping map[string]int
+	list    []*FootnoteDefinition
 }
 
 var emphasisTags = map[string][]string{
@@ -55,6 +61,9 @@ func NewHTMLWriter() *HTMLWriter {
 		HighlightCodeBlock: func(source, lang string) string {
 			return fmt.Sprintf("%s\n<pre>\n%s\n</pre>\n</div>", `<div class="highlight">`, html.EscapeString(source))
 		},
+		footnotes: footnotes{
+			mapping: map[string]int{},
+		},
 	}
 }
 
@@ -129,26 +138,23 @@ func (w *HTMLWriter) WriteInclude(i Include) {
 	WriteNodes(w, i.Resolve())
 }
 
-func (w *HTMLWriter) WriteFootnoteDefinition(FootnoteDefinition) {}
+func (w *HTMLWriter) WriteFootnoteDefinition(f FootnoteDefinition) {
-
+	w.footnotes.updateDefinition(f)
-func (w *HTMLWriter) writeFootnoteDefinition(f FootnoteDefinition) {
-	n := f.Name
-	w.WriteString(`<div class="footnote-definition">` + "\n")
-	w.WriteString(fmt.Sprintf(`<sup id="footnote-%s"><a href="#footnote-reference-%s">%s</a></sup>`, n, n, n) + "\n")
-	w.WriteString(`<div class="footnote-body">` + "\n")
-	WriteNodes(w, f.Children...)
-	w.WriteString("</div>\n</div>\n")
 }
 
 func (w *HTMLWriter) WriteFootnotes(d *Document) {
-	if !w.document.GetOption("f") || len(d.Footnotes.Definitions) == 0 {
+	if !w.document.GetOption("f") || len(w.footnotes.list) == 0 {
 		return
 	}
 	w.WriteString(`<div class="footnotes">` + "\n")
 	w.WriteString(`<hr class="footnotes-separatator">` + "\n")
 	w.WriteString(`<div class="footnote-definitions">` + "\n")
-	for _, definition := range d.Footnotes.Ordered() {
+	for i, definition := range w.footnotes.list {
-		w.writeFootnoteDefinition(definition)
+		w.WriteString(`<div class="footnote-definition">` + "\n")
+		w.WriteString(fmt.Sprintf(`<sup id="footnote-%d"><a href="#footnote-reference-%d">%d</a></sup>`, i, i, i) + "\n")
+		w.WriteString(`<div class="footnote-body">` + "\n")
+		WriteNodes(w, definition.Children...)
+		w.WriteString("</div>\n</div>\n")
 	}
 	w.WriteString("</div>\n</div>\n")
 }
@@ -245,8 +251,8 @@ func (w *HTMLWriter) WriteFootnoteLink(l FootnoteLink) {
 	if !w.document.GetOption("f") {
 		return
 	}
-	n := html.EscapeString(l.Name)
+	id := w.footnotes.add(l)
-	w.WriteString(fmt.Sprintf(`<sup class="footnote-reference"><a id="footnote-reference-%s" href="#footnote-%s">%s</a></sup>`, n, n, n))
+	w.WriteString(fmt.Sprintf(`<sup class="footnote-reference"><a id="footnote-reference-%d" href="#footnote-%d">%d</a></sup>`, id, id, id))
 }
 
 func (w *HTMLWriter) WriteTimestamp(t Timestamp) {
@@ -445,3 +451,21 @@ func setHTMLAttribute(attributes []h.Attribute, k, v string) []h.Attribute {
 	}
 	return append(attributes, h.Attribute{Namespace: "", Key: k, Val: v})
 }
+
+func (fs *footnotes) add(f FootnoteLink) int {
+	if i, ok := fs.mapping[f.Name]; ok && f.Name != "" {
+		return i
+	}
+	fs.list = append(fs.list, f.Definition)
+	i := len(fs.list) - 1
+	if f.Name != "" {
+		fs.mapping[f.Name] = i
+	}
+	return i
+}
+
+func (fs *footnotes) updateDefinition(f FootnoteDefinition) {
+	if i, ok := fs.mapping[f.Name]; ok {
+		fs.list[i] = &f
+	}
+}

org/inline.go

@@ -171,7 +171,6 @@ func (d *Document) parseFootnoteReference(input string, start int) (int, Node) {
 		link := FootnoteLink{name, nil}
 		if definition != "" {
 			link.Definition = &FootnoteDefinition{name, []Node{Paragraph{d.parseInline(definition)}}, true}
-			d.addFootnote(name, link.Definition)
 		}
 		return len(m[0]), link
 	}

org/testdata/footnotes.html

@@ -12,12 +12,12 @@ Using some footnotes
 <ul>
 <li>
 <p>
-normal footnote reference <sup class="footnote-reference"><a id="footnote-reference-1" href="#footnote-1">1</a></sup> <sup class="footnote-reference"><a id="footnote-reference-6" href="#footnote-6">6</a></sup>
+normal footnote reference <sup class="footnote-reference"><a id="footnote-reference-0" href="#footnote-0">0</a></sup> <sup class="footnote-reference"><a id="footnote-reference-1" href="#footnote-1">1</a></sup>
 </p>
 </li>
 <li>
 <p>
-further references to the same footnote should not <sup class="footnote-reference"><a id="footnote-reference-1" href="#footnote-1">1</a></sup> render duplicates in the footnote list
+further references to the same footnote should not <sup class="footnote-reference"><a id="footnote-reference-0" href="#footnote-0">0</a></sup> render duplicates in the footnote list
 </p>
 </li>
 <li>
@@ -28,7 +28,7 @@ inline footnotes are also supported via <sup class="footnote-reference"><a id="f
 <li>
 <p>
 Footnote definitions are not printed where they appear.
-Rather, they are gathered and exported at the end of the document in the footnote section. <sup class="footnote-reference"><a id="footnote-reference-4" href="#footnote-4">4</a></sup>
+Rather, they are gathered and exported at the end of the document in the footnote section. <sup class="footnote-reference"><a id="footnote-reference-3" href="#footnote-3">3</a></sup>
 </p>
 </li>
 </ul>
@@ -36,33 +36,16 @@ Rather, they are gathered and exported at the end of the document in the footnot
 Footnotes
 </h1>
 <p>
-Please note that the footnotes section is not automatically excluded from the export like in emacs. <sup class="footnote-reference"><a id="footnote-reference-7" href="#footnote-7">7</a></sup>
+Please note that the footnotes section is not automatically excluded from the export like in emacs. <sup class="footnote-reference"><a id="footnote-reference-4" href="#footnote-4">4</a></sup>
 </p>
 <p>
-this is not part of <sup class="footnote-reference"><a id="footnote-reference-7" href="#footnote-7">7</a></sup> anymore as there are 2 blank lines in between!
+this is not part of <sup class="footnote-reference"><a id="footnote-reference-4" href="#footnote-4">4</a></sup> anymore as there are 2 blank lines in between!
 </p>
 <div class="footnotes">
 <hr class="footnotes-separatator">
 <div class="footnote-definitions">
 <div class="footnote-definition">
-<sup id="footnote-4"><a href="#footnote-reference-4">4</a></sup>
+<sup id="footnote-0"><a href="#footnote-reference-0">0</a></sup>
-<div class="footnote-body">
-<p>
-so this definition will not be at the end of this section in the exported document.
-Rather, it will be somewhere down below in the footnotes section.
-</p>
-</div>
-</div>
-<div class="footnote-definition">
-<sup id="footnote-5"><a href="#footnote-reference-5">5</a></sup>
-<div class="footnote-body">
-<p>
-another unused footnote (this definition overwrites the previous definition of <code class="verbatim">fn:5</code>)
-</p>
-</div>
-</div>
-<div class="footnote-definition">
-<sup id="footnote-1"><a href="#footnote-reference-1">1</a></sup>
 <div class="footnote-body">
 <p>
 <a href="https://www.example.com">https://www.example.com</a>
@@ -115,15 +98,7 @@ and tables
 </div>
 </div>
 <div class="footnote-definition">
-<sup id="footnote-3"><a href="#footnote-reference-3">3</a></sup>
+<sup id="footnote-1"><a href="#footnote-reference-1">1</a></sup>
-<div class="footnote-body">
-<p>
-<a href="http://example.com/unused-footnote">example.com/unused-footnote</a>
-</p>
-</div>
-</div>
-<div class="footnote-definition">
-<sup id="footnote-6"><a href="#footnote-reference-6">6</a></sup>
 <div class="footnote-body">
 <p>
 Footnotes break after two consecutive empty lines - just like paragraphs - see <a href="https://orgmode.org/worg/dev/org-syntax.html.">https://orgmode.org/worg/dev/org-syntax.html.</a>
@@ -132,15 +107,6 @@ This shouldn&#39;t happen when the definition line and the line after that are e
 </div>
 </div>
 <div class="footnote-definition">
-<sup id="footnote-7"><a href="#footnote-reference-7">7</a></sup>
-<div class="footnote-body">
-<p>
-There&#39;s multiple reasons for that. Among others, doing so requires i18n (to recognize the section) and silently
-hides content before and after the footnotes.
-</p>
-</div>
-</div>
-<div class="footnote-definition">
 <sup id="footnote-2"><a href="#footnote-reference-2">2</a></sup>
 <div class="footnote-body">
 <p>
@@ -148,5 +114,23 @@ the inline footnote definition
 </p>
 </div>
 </div>
+<div class="footnote-definition">
+<sup id="footnote-3"><a href="#footnote-reference-3">3</a></sup>
+<div class="footnote-body">
+<p>
+so this definition will not be at the end of this section in the exported document.
+Rather, it will be somewhere down below in the footnotes section.
+</p>
+</div>
+</div>
+<div class="footnote-definition">
+<sup id="footnote-4"><a href="#footnote-reference-4">4</a></sup>
+<div class="footnote-body">
+<p>
+There&#39;s multiple reasons for that. Among others, doing so requires i18n (to recognize the section) and silently
+hides content before and after the footnotes.
+</p>
+</div>
+</div>
 </div>
 </div>

org/testdata/misc.html

@@ -409,7 +409,7 @@ src/example/export blocks should not be converted!
 <a href="https://github.com/chaseadamsio/goorgeous/issues/87">#87</a>: Markup in footnotes is rendered literally
 </h3>
 <p>
-footnotes can contain <strong>markup</strong> - and other elements and stuff <sup class="footnote-reference"><a id="footnote-reference-2" href="#footnote-2">2</a></sup>
+footnotes can contain <strong>markup</strong> - and other elements and stuff <sup class="footnote-reference"><a id="footnote-reference-0" href="#footnote-0">0</a></sup> <sup class="footnote-reference"><a id="footnote-reference-1" href="#footnote-1">1</a></sup>
 </p>
 <h3 id="headline-23">
 <span class="todo">DONE</span>
@@ -472,7 +472,7 @@ Footnotes
 <hr class="footnotes-separatator">
 <div class="footnote-definitions">
 <div class="footnote-definition">
-<sup id="footnote-1"><a href="#footnote-reference-1">1</a></sup>
+<sup id="footnote-0"><a href="#footnote-reference-0">0</a></sup>
 <div class="footnote-body">
 <p>
 a footnote <em>with</em> <strong>markup</strong>
@@ -492,7 +492,7 @@ because that&#39;s possible
 </div>
 </div>
 <div class="footnote-definition">
-<sup id="footnote-2"><a href="#footnote-reference-2">2</a></sup>
+<sup id="footnote-1"><a href="#footnote-reference-1">1</a></sup>
 <div class="footnote-body">
 <p>
 that also goes for <strong>inline</strong> footnote <em>definitions</em>

org/testdata/misc.org

@@ -108,7 +108,7 @@ also, consecutive dashes inside
   : --, ---
 
 *** DONE [[https://github.com/chaseadamsio/goorgeous/issues/87][#87]]: Markup in footnotes is rendered literally
-footnotes can contain *markup* - and other elements and stuff [fn:2:that also goes for *inline* footnote /definitions/]
+footnotes can contain *markup* - and other elements and stuff [fn:1] [fn:2:that also goes for *inline* footnote /definitions/]
 *** DONE [[https://github.com/chaseadamsio/goorgeous/issues/92][#92]]: src blocks only render in caps
 The behaviour of Org mode =<s TAB= changed and it now inserts lowercased src blocks (go-org already handled this one)
 - lowercased:

org/testdata/misc.pretty_org

@@ -108,7 +108,7 @@ also, consecutive dashes inside
   : --, ---
 
 *** DONE [[https://github.com/chaseadamsio/goorgeous/issues/87][#87]]: Markup in footnotes is rendered literally
-footnotes can contain *markup* - and other elements and stuff [fn:2:that also goes for *inline* footnote /definitions/]
+footnotes can contain *markup* - and other elements and stuff [fn:1] [fn:2:that also goes for *inline* footnote /definitions/]
 *** DONE [[https://github.com/chaseadamsio/goorgeous/issues/92][#92]]: src blocks only render in caps
 The behaviour of Org mode =<s TAB= changed and it now inserts lowercased src blocks (go-org already handled this one)
 - lowercased: