Add basic support for statistic tokens (e.g. [100%] [1/1])

Org mode does not care where those tokens are when it comes to the
export (afaict). We'll do the same.

(They should only be in the first line of a list item or a headline)

org/html.go

@@ -103,6 +103,8 @@ func (w *HTMLWriter) writeNodes(ns ...Node) {
 			w.writeText(n)
 		case Emphasis:
 			w.writeEmphasis(n)
+		case StatisticToken:
+			w.writeStatisticToken(n)
 		case ExplicitLineBreak:
 			w.writeExplicitLineBreak(n)
 		case LineBreak:
@@ -234,6 +236,10 @@ func (w *HTMLWriter) writeEmphasis(e Emphasis) {
 	w.WriteString(tags[1])
 }
 
+func (w *HTMLWriter) writeStatisticToken(s StatisticToken) {
+	w.WriteString(fmt.Sprintf(`<code class="statistic">[%s]</code>`, s.Content))
+}
+
 func (w *HTMLWriter) writeLineBreak(l LineBreak) {
 	w.WriteString(strings.Repeat("\n", l.Count))
 }

org/inline.go

@@ -15,6 +15,8 @@ type Text struct {
 type LineBreak struct{ Count int }
 type ExplicitLineBreak struct{}
 
+type StatisticToken struct{ Content string }
+
 type Emphasis struct {
 	Kind    string
 	Content []Node
@@ -39,6 +41,7 @@ var videoExtensionRegexp = regexp.MustCompile(`^[.](webm|mp4)$`)
 
 var subScriptSuperScriptRegexp = regexp.MustCompile(`([_^])\{(.*?)\}`)
 var footnoteRegexp = regexp.MustCompile(`\[fn:([\w-]+?)(:(.*?))?\]`)
+var statisticsTokenRegexp = regexp.MustCompile(`\[(\d+/\d+|\d+%)\]`)
 
 func (d *Document) parseInline(input string) (nodes []Node) {
 	previous, current := 0, 0
@@ -54,7 +57,7 @@ func (d *Document) parseInline(input string) (nodes []Node) {
 		case '=', '~':
 			consumed, node = d.parseEmphasis(input, current, true)
 		case '[':
-			consumed, node = d.parseRegularLinkOrFootnoteReference(input, current)
+			consumed, node = d.parseOpeningBracket(input, current)
 		case '\\':
 			consumed, node = d.parseExplicitLineBreak(input, current)
 		case '\n':
@@ -140,11 +143,13 @@ func (d *Document) parseSubScriptOrEmphasis(input string, start int) (int, Node)
 	return d.parseEmphasis(input, start, false)
 }
 
-func (d *Document) parseRegularLinkOrFootnoteReference(input string, start int) (int, Node) {
+func (d *Document) parseOpeningBracket(input string, start int) (int, Node) {
 	if len(input[start:]) >= 2 && input[start] == '[' && input[start+1] == '[' {
 		return d.parseRegularLink(input, start)
-	} else if len(input[start:]) >= 1 && input[start] == '[' {
+	} else if footnoteRegexp.MatchString(input[start:]) {
 		return d.parseFootnoteReference(input, start)
+	} else if statisticsTokenRegexp.MatchString(input[start:]) {
+		return d.parseStatisticToken(input, start)
 	}
 	return 0, nil
 }
@@ -162,6 +167,13 @@ func (d *Document) parseFootnoteReference(input string, start int) (int, Node) {
 	return 0, nil
 }
 
+func (d *Document) parseStatisticToken(input string, start int) (int, Node) {
+	if m := statisticsTokenRegexp.FindStringSubmatch(input[start:]); m != nil {
+		return len(m[1]) + 2, StatisticToken{m[1]}
+	}
+	return 0, nil
+}
+
 func (d *Document) parseAutoLink(input string, start int) (int, int, Node) {
 	if !d.AutoLink || len(input[start:]) < 3 || input[start+1] != '/' || input[start+2] != '/' {
 		return 0, 0, nil

org/org.go

@@ -86,6 +86,8 @@ func (w *OrgWriter) writeNodes(ns ...Node) {
 			w.writeText(n)
 		case Emphasis:
 			w.writeEmphasis(n)
+		case StatisticToken:
+			w.writeStatisticToken(n)
 		case LineBreak:
 			w.writeLineBreak(n)
 		case ExplicitLineBreak:
@@ -285,6 +287,10 @@ func (w *OrgWriter) writeEmphasis(e Emphasis) {
 	w.WriteString(borders[1])
 }
 
+func (w *OrgWriter) writeStatisticToken(s StatisticToken) {
+	w.WriteString(fmt.Sprintf("[%s]", s.Content))
+}
+
 func (w *OrgWriter) writeLineBreak(l LineBreak) {
 	w.WriteString(strings.Repeat("\n"+w.indent, l.Count))
 }

org/testdata/headlines.html

@@ -1,6 +1,25 @@
 <h1>
-Simple Headline
+Simple Headline <code class="statistic">[1/2]</code>
 </h1>
+<ul>
+<li>
+<p>
+[X] checked
+</p>
+</li>
+<li>
+<p>
+[ ] unchecked
+</p>
+</li>
+<li>
+<p>
+note that statistic tokens are marked up anywhere
+not just where they are actually meant to be - even here &gt; <code class="statistic">[100%]</code> &lt;
+(Org mode proper does the same)
+</p>
+</li>
+</ul>
 <h1>
 <span class="todo">TODO</span>
 <span class="priority">B</span>

org/testdata/headlines.org

@@ -1,4 +1,9 @@
-* Simple Headline
+* Simple Headline [1/2]
+- [X] checked
+- [ ] unchecked
+- note that statistic tokens are marked up anywhere
+  not just where they are actually meant to be - even here > [100%] <
+  (Org mode proper does the same)
 * TODO [#B] Headline with todo status & priority
 * DONE Headline with TODO status
 :PROPERTIES:

org/testdata/misc.html

@@ -43,7 +43,12 @@ src block
 </p>
 <div class="highlight">
 <pre>
-* Simple Headline
+* Simple Headline [1/2]
+- [X] checked
+- [ ] unchecked
+- note that statistic tokens are marked up anywhere
+  not just where they are actually meant to be - even here &gt; [100%] &lt;
+  (Org mode proper does the same)
 * TODO [#B] Headline with todo status &amp; priority
 * DONE Headline with TODO status
 :PROPERTIES: