From 595a7df8893b0c3451dc47252810e2bf132a219a Mon Sep 17 00:00:00 2001
From: Alex Suraci <suraci.alex@gmail.com>
Date: Mon, 4 Mar 2019 12:21:39 -0500
Subject: [PATCH] add section Next/Prev

these are useful for generating links to the previous and next section
in HTML templates

Signed-off-by: Alex Suraci <suraci.alex@gmail.com>
---
 section.go | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/section.go b/section.go
index a54ab1e..8d11b61 100644
--- a/section.go
+++ b/section.go
@@ -185,6 +185,52 @@ func (con *Section) IsOrHasChild(sub *Section) bool {
 	return false
 }
 
+func (con *Section) Prev() *Section {
+	if con.Parent == nil {
+		return nil
+	}
+
+	var lastChild *Section
+	for _, child := range con.Parent.Children {
+		if lastChild != nil && child == con {
+			return lastChild
+		}
+
+		lastChild = child
+	}
+
+	return con.Parent
+}
+
+func (con *Section) Next() *Section {
+	if con.SplitSections {
+		if len(con.Children) > 0 {
+			return con.Children[0]
+		}
+	}
+
+	return con.NextSibling()
+}
+
+func (con *Section) NextSibling() *Section {
+	if con.Parent == nil {
+		return nil
+	}
+
+	var sawSelf bool
+	for _, child := range con.Parent.Children {
+		if sawSelf {
+			return child
+		}
+
+		if child == con {
+			sawSelf = true
+		}
+	}
+
+	return con.Parent.NextSibling()
+}
+
 func (con *Section) FindTag(tagName string) []Tag {
 	return con.findTag(tagName, true, nil)
 }