Fix example

.gitignore

@@ -1,23 +1,24 @@
-syntax:glob
-*.[568ao]
-*.ao
-*.so
-*.pyc
+*
+!*.*
+!*/
+*.o
 *.swp
+*.tmp
+*.bak
+*.pro.user
+*.dblite
+*.so
 *.swo
-._*
-.nfs.*
-[568a].out
-*~
+*.ao
+*.pyc
 *.orig
 *.pb.go
-core
+*~
+._*
+*.nfs.*
+.vscode
+*CMakeFiles*
 _obj
 _test
-src/pkg/Make.deps
 _testmain.go
-
-syntax:regexp
-^pkg/
-^src/cmd/(.*)/6?\1$
-^.*/core.[0-9]*$
+!img/*

.travis.yml

@@ -0,0 +1,6 @@
+language: go
+
+go:
+    - "1.11"
+    - "1.12"
+    - "1.13"

README.md

@@ -1,11 +1,11 @@
-# GoLLRB
+# GoLLRB [![Build Status](https://travis-ci.com/petar/GoLLRB.svg?branch=master)](https://travis-ci.com/petar/GoLLRB) [![Go Report Card](https://goreportcard.com/badge/github.com/petar/GoLLRB)](https://goreportcard.com/report/github.com/petar/GoLLRB) [![GoDoc](https://godoc.org/github.com/petar/GoLLRB?status.svg)](https://godoc.org/github.com/petar/GoLLRB)
 
 GoLLRB is a Left-Leaning Red-Black (LLRB) implementation of 2-3 balanced binary
 search trees in Go Language.
 
 ## Overview
 
-As of this writing and to the best of the author's knowledge, 
+As of this writing and to the best of the author's knowledge,
 Go still does not have a balanced binary search tree (BBST) data structure.
 These data structures are quite useful in a variety of cases. A BBST maintains
 elements in sorted order under dynamic updates (inserts and deletes) and can
@@ -28,39 +28,41 @@ I consider it to be in stable, perhaps even production, shape. There are no know
 
 ## Installation
 
-With a healthy Go Language installed, simply run `go get github.com/petar/GoLLRB/llrb`
+With a healthy Go Language installed, simply run `go get -u github.com/petar/GoLLRB/llrb`
 
 ## Example
-
-	package main
-
-	import (
-		"fmt"
-		"github.com/petar/GoLLRB/llrb"
-	)
-
-	func lessInt(a, b interface{}) bool { return a.(int) < b.(int) }
-
-	func main() {
-		tree := llrb.New(lessInt)
-		tree.ReplaceOrInsert(1)
-		tree.ReplaceOrInsert(2)
-		tree.ReplaceOrInsert(3)
-		tree.ReplaceOrInsert(4)
-		tree.DeleteMin()
-		tree.Delete(4)
-		c := tree.IterAscend()
-		for {
-			u := <-c
-			if u == nil {
-				break
-			}
-			fmt.Printf("%d\n", int(u.(int)))
-		}
-	}
 
-## About
+```go
+package main
+
+import (
+	"fmt"
+
+	"github.com/petar/GoLLRB/llrb"
+)
+
+func lessInt(a, b interface{}) bool { return a.(int) < b.(int) }
 
-GoLLRB was written by [Petar Maymounkov](http://pdos.csail.mit.edu/~petar/). 
+func main() {
+	tree := llrb.New()
+	tree.ReplaceOrInsert(llrb.Int(1))
+	tree.ReplaceOrInsert(llrb.Int(2))
+	tree.ReplaceOrInsert(llrb.Int(3))
+	tree.ReplaceOrInsert(llrb.Int(4))
+	tree.DeleteMin()         // Delete 1
+	tree.Delete(llrb.Int(4)) // Delete 4
+
+	// Will output:
+	// 2 llrb.Int
+	// 3 llrb.Int
+	tree.AscendGreaterOrEqual(llrb.Int(-1), func(i llrb.Item) bool {
+		fmt.Printf("%d %T\n", i, i)
+		return true
+	})
+}
+```
+
+## About
 
-Follow me on [Twitter @maymounkov](http://www.twitter.com/maymounkov)!
+* GoLLRB was written by [Petar Maymounkov](http://pdos.csail.mit.edu/~petar/).
+* Follow me on [Twitter @maymounkov](http://www.twitter.com/maymounkov)!

example/main.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/petar/GoLLRB/llrb"
+)
+
+func lessInt(a, b interface{}) bool { return a.(int) < b.(int) }
+
+func main() {
+	tree := llrb.New()
+	tree.ReplaceOrInsert(llrb.Int(1))
+	tree.ReplaceOrInsert(llrb.Int(2))
+	tree.ReplaceOrInsert(llrb.Int(3))
+	tree.ReplaceOrInsert(llrb.Int(4))
+	tree.DeleteMin()         // Delete 1
+	tree.Delete(llrb.Int(4)) // Delete 4
+
+	// Will output:
+	// 2 llrb.Int
+	// 3 llrb.Int
+	tree.AscendGreaterOrEqual(llrb.Int(-1), func(i llrb.Item) bool {
+		fmt.Printf("%d %T\n", i, i)
+		return true
+	})
+}

go.mod

@@ -0,0 +1,3 @@
+module github.com/petar/GoLLRB/llrb
+
+go 1.11