Fixing code examples, statement about working tests on code examples

README.md

@@ -74,6 +74,10 @@ You should start with [the template](template.md). Copy it into the appropriate
 directory, edit it, and submit a PR. You might not want every section, and you
 might want to add extra sections.
 
+When writing examples, please try to make them compile. This allows us to test
+them. If you fail to write an example that is both complete and readable,
+please at least mark your example code with `ignore`.
+
 We suggest leaving a comment on the [issue tracker](https://github.com/rust-unofficial/patterns/issues)
 so that other people don't start working on the same topic.
 

idioms/ctor.md

@@ -8,7 +8,7 @@ is to use a static `new` method to create an object.
 
 ## Example
 
-```rust
+```rust,ignore
 // A Rust vector, see liballoc/vec.rs
 pub struct Vec<T> {
     buf: RawVec<T>,

idioms/deref.md

@@ -8,16 +8,16 @@ and borrowed views of data.
 
 ## Example
 
-```rust
+```rust,ignore
 struct Vec<T> {
-    ...
+    //..
 }
 
 impl<T> Deref for Vec<T> {
     type Target = [T];
 
     fn deref(&self) -> &[T] {
-        ...
+        unimplemented!()
     }
 }
 ```

idioms/dtor-finally.md

@@ -10,6 +10,8 @@ be used to run code that must be run before exit.
 ## Example
 
 ```rust
+fn baz() -> Result<(), ()> { Ok(()) }
+
 fn bar() -> Result<(), ()> {
     // These don't need to be defined inside the function.
     struct Foo;

idioms/pass-var-to-closure.md

@@ -14,6 +14,8 @@ Use variable rebinding in separate scope for that.
 Use
 
 ```rust
+use std::rc::Rc;
+
 let num1 = Rc::new(1);
 let num2 = Rc::new(2);
 let num3 = Rc::new(3);
@@ -30,6 +32,8 @@ let closure = {
 instead of
 
 ```rust
+use std::rc::Rc;
+
 let num1 = Rc::new(1);
 let num2 = Rc::new(2);
 let num3 = Rc::new(3);

idioms/priv-extend.md

@@ -18,7 +18,7 @@ mod a {
     }
 }
 
-fn main(s: a::S) {
+fn any(s: a::S) {
     // Because S::bar is private, it cannot be named here and we must use `..`
     // in the pattern.
     let a::S { foo: _, ..} = s;

patterns/builder.md

@@ -7,7 +7,7 @@ Construct an object with calls to a builder helper.
 
 ## Example
 
-```rust
+```rust,ignore
 struct Foo {
     // Lots of complicated fields.
 }
@@ -85,7 +85,7 @@ The example takes and returns the builder by value. It is often more ergonomic
 borrow checker makes this work naturally. This approach has the advantage that
 one can write code like
 
-```
+```rust,ignore
 let mut fb = FooBuilder::new();
 fb.a();
 fb.b();

patterns/compose-structs.md

@@ -20,7 +20,7 @@ pattern often reveals smaller units of functionality.
 Here is a contrived example of where the borrow checker foils us in our plan to
 use a struct:
 
-```rust
+```rust,ignore
 struct A {
     f1: u32,
     f2: u32,
@@ -30,7 +30,7 @@ struct A {
 fn foo(a: &mut A) -> &u32 { &a.f2 }
 fn bar(a: &mut A) -> u32 { a.f1 + a.f3 }
 
-fn main(a: &mut A) {
+fn baz(a: &mut A) {
     // x causes a to be borrowed for the rest of the function.
     let x = foo(a);
     // Borrow check error
@@ -59,7 +59,7 @@ struct C {
 fn foo(b: &mut B) -> &u32 { &b.f2 }
 fn bar(c: &mut C) -> u32 { c.f1 + c.f3 }
 
-fn main(a: &mut A) {
+fn baz(a: &mut A) {
     let x = foo(&mut a.b);
     // Now it's OK!
     let y = bar(&mut a.c);

patterns/fold.md

@@ -11,7 +11,7 @@ fold in the usual sense. See the discussion below for more details.
 
 ## Example
 
-```rust
+```rust,ignore
 // The data we will fold, a simple AST.
 mod ast {
     pub enum Stmt {