refactoring paragraph rendering

block.go

@@ -1035,17 +1035,23 @@ func blockListItem(out *bytes.Buffer, rndr *render, data []byte, flags *int) int
 
 // render a single paragraph that has already been parsed out
 func renderParagraph(out *bytes.Buffer, rndr *render, data []byte) {
-	// trim trailing newlines
+	// trim leading whitespace
+	beg := 0
+	for beg < len(data) && isspace(data[beg]) {
+		beg++
+	}
+
+	// trim trailing whitespace
 	end := len(data)
-	for end > 0 && data[end-1] == '\n' {
+	for end > beg && isspace(data[end-1]) {
 		end--
 	}
-	if end == 0 || rndr.mk.Paragraph == nil {
+	if end == beg || rndr.mk.Paragraph == nil {
 		return
 	}
 
 	var work bytes.Buffer
-	parseInline(&work, rndr, data[:end])
+	parseInline(&work, rndr, data[beg:end])
 	rndr.mk.Paragraph(out, work.Bytes(), rndr.mk.Opaque)
 }
 

html.go

@@ -388,46 +388,30 @@ func htmlListItem(out *bytes.Buffer, text []byte, flags int, opaque interface{})
 
 func htmlParagraph(out *bytes.Buffer, text []byte, opaque interface{}) {
 	options := opaque.(*htmlOptions)
-	i := 0
 
 	if out.Len() > 0 {
 		out.WriteByte('\n')
 	}
 
-	if len(text) == 0 {
-		return
-	}
-
-	for i < len(text) && isspace(text[i]) {
-		i++
-	}
-
-	if i == len(text) {
-		return
-	}
-
 	out.WriteString("<p>")
 	if options.flags&HTML_HARD_WRAP != 0 {
-		for i < len(text) {
-			org := i
-			for i < len(text) && text[i] != '\n' {
-				i++
+		org := 0
+		for i := 0; i < len(text); i++ {
+			if text[i] != '\n' {
+				continue
 			}
 
 			if i > org {
 				out.Write(text[org:i])
 			}
+			org = i
 
-			if i >= len(text) {
-				break
-			}
-
-			out.WriteString("<br>")
+			out.WriteString("<br")
 			out.WriteString(options.closeTag)
-			i++
 		}
+		out.Write(text[org:])
 	} else {
-		out.Write(text[i:])
+		out.Write(text)
 	}
 	out.WriteString("</p>\n")
 }