Add testable examples for base58 package.

This commit creates and an example test file for the baes58 package that
integrates nicely with Go's example tooling.

This allows the example output to be tested as a part of running the
normal Go tests to help ensure it doesn't get out of date with the code.

base58/README.md

@@ -30,6 +30,21 @@ http://localhost:6060/pkg/github.com/conformal/btcutil/base58
 $ go get github.com/conformal/btcutil/base58
 ```
 
+## Examples
+
+* [Decode Example]
+  (http://godoc.org/github.com/conformal/btcutil/base58#example-Decode)  
+  Demonstrates how to decode modified base58 encoded data.
+* [Encode Example]
+  (http://godoc.org/github.com/conformal/btcutil/base58#example-Encode)  
+  Demonstrates how to encode data using the modified base58 encoding scheme.
+* [CheckDecode Example]
+  (http://godoc.org/github.com/conformal/btcutil/base58#example-CheckDecode)  
+  Demonstrates how to decode Base58Check encoded data.
+* [CheckEncode Example]
+  (http://godoc.org/github.com/conformal/btcutil/base58#example-CheckEncode)  
+  Demonstrates how to encode data using the Base58Check encoding scheme.
+
 ## License
 
 Package base58 is licensed under the [copyfree](http://copyfree.org) ISC

base58/example_test.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2014 Conformal Systems LLC.
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package base58_test
+
+import (
+	"fmt"
+
+	"github.com/conformal/btcutil/base58"
+)
+
+// This example demonstrates how to decode modified base58 encoded data.
+func ExampleDecode() {
+	// Decode example modified base58 encoded data.
+	encoded := "25JnwSn7XKfNQ"
+	decoded := base58.Decode(encoded)
+
+	// Show the decoded data.
+	fmt.Println("Decoded Data:", string(decoded))
+
+	// Output:
+	// Decoded Data: Test data
+}
+
+// This example demonstrates how to encode data using the modified base58
+// encoding scheme.
+func ExampleEncode() {
+	// Encode example data with the modified base58 encoding scheme.
+	data := []byte("Test data")
+	encoded := base58.Encode(data)
+
+	// Show the encoded data.
+	fmt.Println("Encoded Data:", encoded)
+
+	// Output:
+	// Encoded Data: 25JnwSn7XKfNQ
+}
+
+// This example demonstrates how to decode Base58Check encoded data.
+func ExampleCheckDecode() {
+	// Decode an example Base58Check encoded data.
+	encoded := "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa"
+	decoded, version, err := base58.CheckDecode(encoded)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	// Show the decoded data.
+	fmt.Printf("Decoded data: %x\n", decoded)
+	fmt.Println("Version Byte:", version)
+
+	// Output:
+	// Decoded data: 62e907b15cbf27d5425399ebf6f0fb50ebb88f18
+	// Version Byte: 0
+}
+
+// This example demonstrates how to encode data using the Base58Check encoding
+// scheme.
+func ExampleCheckEncode() {
+	// Encode example data with the Base58Check encoding scheme.
+	data := []byte("Test data")
+	encoded := base58.CheckEncode(data, 0)
+
+	// Show the encoded data.
+	fmt.Println("Encoded Data:", encoded)
+
+	// Output:
+	// Encoded Data: 182iP79GRURMp7oMHDU
+}