From b3c64946051e90924054f0ec721092dbfbcda1f2 Mon Sep 17 00:00:00 2001
From: Russ Ross <russ@russross.com>
Date: Sun, 11 Mar 2012 16:10:42 -0600
Subject: [PATCH] recognize fraction slash as well as regular slash to make
 fractions

---
 smartypants.go | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/smartypants.go b/smartypants.go
index 589feb0..797de91 100644
--- a/smartypants.go
+++ b/smartypants.go
@@ -256,6 +256,7 @@ func smartBacktick(out *bytes.Buffer, smrt *smartypantsData, previousChar byte,
 func smartNumberGeneric(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
 	if wordBoundary(previousChar) && len(text) >= 3 {
 		// is it of the form digits/digits(word boundary)?, i.e., \d+/\d+\b
+		// note: check for regular slash (/) or fraction slash (⁄, 0x2044, or 0xe2 81 84 in utf-8)
 		numEnd := 0
 		for len(text) > numEnd && isdigit(text[numEnd]) {
 			numEnd++
@@ -264,15 +265,18 @@ func smartNumberGeneric(out *bytes.Buffer, smrt *smartypantsData, previousChar b
 			out.WriteByte(text[0])
 			return 0
 		}
-		if len(text) < numEnd+2 || text[numEnd] != '/' {
+		denStart := numEnd + 1
+		if len(text) > numEnd+3 && text[numEnd] == 0xe2 && text[numEnd+1] == 0x81 && text[numEnd+2] == 0x84 {
+			denStart = numEnd + 3
+		} else if len(text) < numEnd+2 || text[numEnd] != '/' {
 			out.WriteByte(text[0])
 			return 0
 		}
-		denEnd := numEnd + 1
+		denEnd := denStart
 		for len(text) > denEnd && isdigit(text[denEnd]) {
 			denEnd++
 		}
-		if denEnd == numEnd+1 {
+		if denEnd == denStart {
 			out.WriteByte(text[0])
 			return 0
 		}
@@ -280,7 +284,7 @@ func smartNumberGeneric(out *bytes.Buffer, smrt *smartypantsData, previousChar b
 			out.WriteString("<sup>")
 			out.Write(text[:numEnd])
 			out.WriteString("</sup>&frasl;<sub>")
-			out.Write(text[numEnd+1 : denEnd])
+			out.Write(text[denStart:denEnd])
 			out.WriteString("</sub>")
 			return denEnd - 1
 		}