content: rename articles to reinforce convention of short URLs

The Go blog started out on Blogger
(http://web.archive.org/web/20100325005843/http://blog.golang.org/).
Later, we moved to the current self-hosted blog server
with extra Go-specific functionality like playground snippets.

The old Blogger posts have very long URLs that Blogger chose
for us, such as "go-programming-language-turns-two" or
"two-go-talks-lexical-scanning-in-go-and", predating
the convention of giving posts shorter, more share-friendly,
typeable names.

The conversion of the old Blogger posts also predated
the convention of putting supporting files in a subdirectory.

The result is that although we've established new conventions,
you wouldn't know by listing the directory - the old Blogger
content presents a conflicting picture.

This commit renames the posts with very long names
to have shorter, more share-friendly names, and it moves
all supporting files to subdirectories. It also adds a README
documenting the conventions.

For example, blog.golang.org/go-programming-language-turns-two
is now blog.golang.org/2years, matching our more recent birthday
post URLs, and its supporting files are moved to the new 2years/ directory.

The old URLs redirect to the new ones.

Change-Id: I9f46a790c2c8fab8459aeda73d4e3d2efc86d88f
Reviewed-on: https://go-review.googlesource.com/c/blog/+/223599
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>

2 files changed, 63 insertions, 0 deletions

diff --git a/content/maps/list.go b/content/maps/list.go
new file mode 100644
index 0000000..02bea2c
--- /dev/null
+++ b/content/maps/list.go
@@ -0,0 +1,29 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build OMIT
+
+package main
+
+import "fmt"
+
+func main() {
+	// START OMIT
+	type Node struct {
+		Next  *Node
+		Value interface{}
+	}
+	var first *Node
+
+	visited := make(map[*Node]bool) // HL
+	for n := first; n != nil; n = n.Next {
+		if visited[n] { // HL
+			fmt.Println("cycle detected")
+			break
+		}
+		visited[n] = true // HL
+		fmt.Println(n.Value)
+	}
+	// END OMIT
+}
diff --git a/content/maps/people.go b/content/maps/people.go
new file mode 100644
index 0000000..ff5d9e3
--- /dev/null
+++ b/content/maps/people.go
@@ -0,0 +1,34 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build OMIT
+
+package main
+
+import "fmt"
+
+func main() {
+	// START1 OMIT
+	type Person struct {
+		Name  string
+		Likes []string
+	}
+	var people []*Person
+
+	likes := make(map[string][]*Person) // HL
+	for _, p := range people {
+		for _, l := range p.Likes {
+			likes[l] = append(likes[l], p) // HL
+		}
+	}
+	// END1 OMIT
+
+	// START2 OMIT
+	for _, p := range likes["cheese"] {
+		fmt.Println(p.Name, "likes cheese.")
+	}
+	// END2 OMIT
+
+	fmt.Println(len(likes["bacon"]), "people like bacon.")
+}