Implementation and some tests for inline footnotes. Also I noticed the list items had the wrong ids, that was silly of me.

html.go

@@ -333,7 +333,7 @@ func (options *Html) FootnoteItem(out *bytes.Buffer, name, text []byte, flags in
 	if flags&LIST_ITEM_CONTAINS_BLOCK != 0 || flags&LIST_ITEM_BEGINNING_OF_LIST != 0 {
 		doubleSpace(out)
 	}
-	out.WriteString(`<li class="`)
+	out.WriteString(`<li id="fn:`)
 	out.Write(slugify(name))
 	out.WriteString(`">`)
 	out.Write(text)

inline.go

@@ -15,6 +15,7 @@ package blackfriday
 
 import (
 	"bytes"
+	"strconv"
 )
 
 // Functions to parse text within a block
@@ -174,8 +175,7 @@ const (
 	linkNormal linkType = iota
 	linkImg
 	linkDeferredFootnote
-
-//	linkInlineFootnote
+	linkInlineFootnote
 )
 
 // '[': parse a link or an image or a footnote
@@ -193,7 +193,9 @@ func link(p *parser, out *bytes.Buffer, data []byte, offset int) int {
 	if offset > 0 && data[offset-1] == '!' {
 		t = linkImg
 	} else if p.flags&EXTENSION_FOOTNOTES != 0 {
-		if len(data)-1 > offset && data[offset+1] == '^' {
+		if offset > 0 && data[offset-1] == '^' {
+			t = linkInlineFootnote
+		} else if len(data)-1 > offset && data[offset+1] == '^' {
 			t = linkDeferredFootnote
 		}
 	}
@@ -387,7 +389,7 @@ func link(p *parser, out *bytes.Buffer, data []byte, offset int) int {
 		title = lr.title
 		i++
 
-	// shortcut reference style link or footnote
+	// shortcut reference style link or reference or inline footnote
 	default:
 		var id []byte
 
@@ -407,24 +409,58 @@ func link(p *parser, out *bytes.Buffer, data []byte, offset int) int {
 			id = b.Bytes()
 		} else {
 			if t == linkDeferredFootnote {
-				id = data[2:txtE]
+				id = data[2:txtE] // get rid of the ^
 			} else {
 				id = data[1:txtE]
 			}
 		}
 
-		// find the reference with matching id
 		key := string(bytes.ToLower(id))
-		lr, ok := p.refs[key]
-		if !ok {
-			return 0
-		}
+		if t == linkInlineFootnote {
+			// create a new reference
+			noteId = len(p.notes) + 1
 
-		// keep link and title from reference
-		link = lr.link
-		// if inline footnote, title == footnote contents
-		title = lr.title
-		noteId = lr.noteId
+			var fragment []byte
+			if len(id) > 0 {
+				if len(id) < 16 {
+					fragment = make([]byte, len(id))
+				} else {
+					fragment = make([]byte, 16)
+				}
+				copy(fragment, slugify(id))
+			} else {
+				fragment = append([]byte("footnote-"), []byte(strconv.Itoa(noteId))...)
+			}
+
+			ref := &reference{
+				noteId:   noteId,
+				hasBlock: false,
+				link:     fragment,
+				title:    id,
+			}
+
+			p.notes = append(p.notes, ref)
+
+			link = ref.link
+			title = ref.title
+		} else {
+			// find the reference with matching id
+			lr, ok := p.refs[key]
+			if !ok {
+				return 0
+			}
+
+			if t == linkDeferredFootnote {
+				lr.noteId = len(p.notes) + 1
+				p.notes = append(p.notes, lr)
+			}
+
+			// keep link and title from reference
+			link = lr.link
+			// if inline footnote, title == footnote contents
+			title = lr.title
+			noteId = lr.noteId
+		}
 
 		// rewind the whitespace
 		i = txtE + 1
@@ -470,6 +506,15 @@ func link(p *parser, out *bytes.Buffer, data []byte, offset int) int {
 
 		p.r.Image(out, uLink, title, content.Bytes())
 
+	case linkInlineFootnote:
+		outSize := out.Len()
+		outBytes := out.Bytes()
+		if outSize > 0 && outBytes[outSize-1] == '^' {
+			out.Truncate(outSize - 1)
+		}
+
+		p.r.FootnoteRef(out, link, noteId)
+
 	case linkDeferredFootnote:
 		p.r.FootnoteRef(out, link, noteId)
 

inline_test.go

@@ -513,7 +513,7 @@ func TestFootnotes(t *testing.T) {
 <hr />
 
 <ol>
-<li class="a">This is the note
+<li id="fn:a">This is the note
 </li>
 </ol>
 </div>
@@ -539,7 +539,7 @@ No longer in the footnote
 <hr />
 
 <ol>
-<li class="b"><p>Paragraph 1</p>
+<li id="fn:b"><p>Paragraph 1</p>
 
 <p>Paragraph 2</p>
 
@@ -577,9 +577,39 @@ what happens here
 <hr />
 
 <ol>
-<li class="c">this is <a href="/link/c">note</a> c
+<li id="fn:c">this is <a href="/link/c">note</a> c
 </li>
-<li class="d">this is note d
+<li id="fn:d">this is note d
+</li>
+</ol>
+</div>
+`,
+
+		"testing inline^[this is the note] notes.\n",
+		`<p>testing inline<sup class="footnote-ref" id="fnref:this-is-the-note"><a rel="footnote" href="#fn:this-is-the-note">1</a></sup> notes.</p>
+<div class="footnotes">
+
+<hr />
+
+<ol>
+<li id="fn:this-is-the-note">this is the note</li>
+</ol>
+</div>
+`,
+
+		"testing multiple[^1] types^[inline note] of notes[^2]\n\n[^2]: the second deferred note\n[^1]: the first deferred note\n\n\twhich happens to be a block\n",
+		`<p>testing multiple<sup class="footnote-ref" id="fnref:1"><a rel="footnote" href="#fn:1">1</a></sup> types<sup class="footnote-ref" id="fnref:inline-note"><a rel="footnote" href="#fn:inline-note">2</a></sup> of notes<sup class="footnote-ref" id="fnref:2"><a rel="footnote" href="#fn:2">3</a></sup></p>
+<div class="footnotes">
+
+<hr />
+
+<ol>
+<li id="fn:1"><p>the first deferred note</p>
+
+<p>which happens to be a block</p>
+</li>
+<li id="fn:inline-note">inline note</li>
+<li id="fn:2">the second deferred note
 </li>
 </ol>
 </div>

markdown.go

@@ -436,7 +436,9 @@ func isReference(p *parser, data []byte, tabSize int) int {
 	i++
 	if p.flags&EXTENSION_FOOTNOTES != 0 {
 		if data[i] == '^' {
-			noteId = len(p.notes) + 1
+			// we can set it to anything here because the proper noteIds will
+			// be assigned later during the second pass. It just has to be != 0
+			noteId = 1
 			i++
 		}
 	}
@@ -479,7 +481,7 @@ func isReference(p *parser, data []byte, tabSize int) int {
 		hasBlock              bool
 	)
 
-	if p.flags&EXTENSION_FOOTNOTES != 0 && noteId > 0 {
+	if p.flags&EXTENSION_FOOTNOTES != 0 && noteId != 0 {
 		linkOffset, linkEnd, raw, hasBlock = scanFootnote(p, data, i, tabSize)
 		lineEnd = linkEnd
 	} else {
@@ -501,7 +503,6 @@ func isReference(p *parser, data []byte, tabSize int) int {
 		ref.link = data[idOffset:idEnd]
 		// if footnote, it's not really a title, it's the contained text
 		ref.title = raw
-		p.notes = append(p.notes, ref)
 	} else {
 		ref.link = data[linkOffset:linkEnd]
 		ref.title = data[titleOffset:titleEnd]