cue: implementation of marked defaults

Change-Id: I7b0ed2b1e372a71410cbd05253ca819f08509a2a
diff --git a/doc/tutorial/basics/coalesce.md b/doc/tutorial/basics/coalesce.md
index 082708a..dde8c77 100644
--- a/doc/tutorial/basics/coalesce.md
+++ b/doc/tutorial/basics/coalesce.md
@@ -29,11 +29,11 @@
 ```
 list: [ "Cat", "Mouse", "Dog" ]
 
-a: list[0] | "None"
-b: list[5] | "None"
+a: *list[0] | "None"
+b: *list[5] | "None"
 
 n: [null]
-v: n[0] & string | "default"
+v: *n[0] & string | "default"
 ```
 
 <!-- result -->
diff --git a/doc/tutorial/basics/defaults.md b/doc/tutorial/basics/defaults.md
index a46825d..c65cb67 100644
--- a/doc/tutorial/basics/defaults.md
+++ b/doc/tutorial/basics/defaults.md
@@ -19,11 +19,11 @@
 <!-- CUE editor -->
 ```
 // any positive number, 1 is the default
-replicas: 1 | uint
+replicas: uint | *1
 
 // the default value is ambiguous
-protocol: "tcp" | "udp"
-protocol: "udp" | "tcp"
+protocol: *"tcp" | "udp"
+protocol: *"udp" | "tcp"
 ```
 
 <!-- result -->
diff --git a/doc/tutorial/basics/templates.md b/doc/tutorial/basics/templates.md
index 3748cdb..bd40c2a 100644
--- a/doc/tutorial/basics/templates.md
+++ b/doc/tutorial/basics/templates.md
@@ -18,7 +18,7 @@
 // The name of each element is bound to Name and visible in the struct.
 job <Name>: {
     name:     Name
-    replicas: 1 | uint
+    replicas: uint | *1
     command:  string
 }