doc: update docs in a few places

This fixes some examples, including the README, and adds doc_comment to
check that the README remains up to date.

Cargo.toml

@@ -26,3 +26,6 @@ debug = true
 
 [profile.test]
 opt-level = 3
+
+[dev-dependencies]
+doc-comment = "0.3.1"

README.md

@@ -43,7 +43,7 @@ fn main() {
 
     let mut rdr = stdin.lock();
     // Wrap the stdout writer in a Snappy writer.
-    let mut wtr = snap::Writer::new(stdout.lock());
+    let mut wtr = snap::write::FrameEncoder::new(stdout.lock());
     io::copy(&mut rdr, &mut wtr).expect("I/O operation failed");
 }
 ```

src/error.rs

@@ -5,11 +5,11 @@ use std::result;
 /// A convenient type alias for `Result<T, snap::Error>`.
 pub type Result<T> = result::Result<T, Error>;
 
-/// `IntoInnerError` occurs when consuming a `Writer` fails.
+/// `IntoInnerError` occurs when consuming an encoder fails.
 ///
-/// Consuming the `Writer` causes a flush to happen. If the flush fails, then
-/// this error is returned, which contains both the original `Writer` and
-/// the error that occurred.
+/// Consuming the encoder causes a flush to happen. If the flush fails, then
+/// this error is returned, which contains both the original encoder and the
+/// error that occurred.
 ///
 /// The type parameter `W` is the unconsumed writer.
 pub struct IntoInnerError<W> {

src/lib.rs

@@ -48,7 +48,7 @@ you automatically convert a Snappy error to an `std::io::Error` (when using
 This program reads data from `stdin`, compresses it and emits it to `stdout`.
 This example can be found in `examples/compress.rs`:
 
-```rust,ignore
+```no_run
 use std::io;
 
 fn main() {
@@ -57,7 +57,7 @@ fn main() {
 
     let mut rdr = stdin.lock();
     // Wrap the stdout writer in a Snappy writer.
-    let mut wtr = snap::Writer::new(stdout.lock());
+    let mut wtr = snap::write::FrameEncoder::new(stdout.lock());
     io::copy(&mut rdr, &mut wtr).expect("I/O operation failed");
 }
 ```
@@ -67,7 +67,7 @@ fn main() {
 This program reads data from `stdin`, decompresses it and emits it to `stdout`.
 This example can be found in `examples/decompress.rs`:
 
-```rust,ignore
+```no_run
 use std::io;
 
 fn main() {
@@ -84,6 +84,9 @@ fn main() {
 
 #![deny(missing_docs)]
 
+#[cfg(test)]
+doc_comment::doctest!("../README.md");
+
 pub use crate::error::{Error, Result};
 
 /// We don't permit compressing a block bigger than what can fit in a u32.

src/write.rs

@@ -36,8 +36,8 @@ use crate::MAX_BLOCK_SIZE;
 pub struct FrameEncoder<W: io::Write> {
     /// Our main internal state, split out for borrowck reasons (happily paid).
     ///
-    /// Also, it's an `Option` so we can move out of it even though `Writer`
-    /// impls `Drop`.
+    /// Also, it's an `Option` so we can move out of it even though
+    /// `FrameEncoder` impls `Drop`.
     inner: Option<Inner<W>>,
     /// Our buffer of uncompressed bytes. This isn't part of `inner` because
     /// we may write bytes directly from the caller if the given buffer was