Fix some minor weirdness when Pilcrow is (unwisely) used as a library.

Pilcrow isn't meant to be used as a library, and the only public interface the `pilcrow` lib crate exposes is the CLI entry point. However, we will likely be publishing Pilcrow via crates.io (among other options) one day, and so it will _be usable_ as a library if someone's desperate enough to try. To that end, let's try to be good citizens.

This change fixes two issues:

* The docs contained links to internal items, which are not actually included in the library documentation. The links are simply removed; the uses of those items were already private anyways.

* The CLI `Error` type is no longer part of the public interface, using `impl Trait` (`impl std::error::Error`) shenanigans to hide the error type from callers. (To be clear, this would be _extremely_ rude in code intended for library use.) This frees us up to change the structure of the error type - or to replace it entirely - without making the world's most pedantic semver change in the process.

Merges lib-crate-weirdness into main.

1 files changed, 4 insertions, 9 deletions

diff --git a/src/cli.rs b/src/cli.rs
index 57c5c07..703bf19 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -84,11 +84,10 @@ impl Args {
     /// # Errors
     ///
     /// Will return `Err` if the server is unable to start, or terminates
-    /// prematurely. The specific [`Error`] variant will expose the cause
+    /// prematurely. The returned error contains a user-facing explanation
     /// of the failure.
-    pub async fn run(self) -> Result<(), Error> {
+    pub async fn run(self) -> Result<(), impl std::error::Error> {
         self.umask.set();
-
         let pool = self.pool().await?;
 
         let app = App::from(pool);
@@ -104,7 +103,7 @@ impl Args {
         println!("{started_msg}");
         serve.await?;
 
-        Ok(())
+        Result::<_, Error>::Ok(())
     }
 
     async fn listener(&self) -> io::Result<net::TcpListener> {
@@ -138,14 +137,10 @@ fn started_msg(listener: &net::TcpListener) -> io::Result<String> {
     Ok(format!("listening on http://{local_addr}/"))
 }
 
-/// Errors that can be raised by [`Args::run`].
 #[derive(Debug, thiserror::Error)]
 #[error(transparent)]
-pub enum Error {
-    /// Failure due to `io::Error`. See [`io::Error`].
+enum Error {
     Io(#[from] io::Error),
-    /// Failure due to a database initialization error. See [`db::Error`].
     Database(#[from] db::Error),
-    /// Failure due to invalid umask-related options.
     Umask(#[from] umask::Error),
 }