Impl 'FromForm' for char, 'Range' types.

Implements 'FromForm' for:

  * `char`
  * `Range<T: FromForm>`
  * `RangeFrom<T: FromForm>`
  * `RangeTo<T: FromForm>`
  * `RangeToInclusive<T: FromForm>`

Resolves #2759.

core/lib/src/form/error.rs

@@ -3,6 +3,7 @@
 use std::{fmt, io};
 use std::num::{ParseIntError, ParseFloatError};
 use std::str::{Utf8Error, ParseBoolError};
+use std::char::ParseCharError;
 use std::net::AddrParseError;
 use std::borrow::Cow;
 
@@ -200,6 +201,8 @@ pub enum ErrorKind<'v> {
     Multipart(multer::Error),
     /// A string was invalid UTF-8.
     Utf8(Utf8Error),
+    /// A value failed to parse as a char.
+    Char(ParseCharError),
     /// A value failed to parse as an integer.
     Int(ParseIntError),
     /// A value failed to parse as a boolean.
@@ -857,6 +860,7 @@ impl fmt::Display for ErrorKind<'_> {
             ErrorKind::Custom(_, e) => e.fmt(f)?,
             ErrorKind::Multipart(e) => write!(f, "invalid multipart: {}", e)?,
             ErrorKind::Utf8(e) => write!(f, "invalid UTF-8: {}", e)?,
+            ErrorKind::Char(e) => write!(f, "invalid character: {}", e)?,
             ErrorKind::Int(e) => write!(f, "invalid integer: {}", e)?,
             ErrorKind::Bool(e) => write!(f, "invalid boolean: {}", e)?,
             ErrorKind::Float(e) => write!(f, "invalid float: {}", e)?,
@@ -885,6 +889,7 @@ impl crate::http::ext::IntoOwned for ErrorKind<'_> {
             Custom(s, e) => Custom(s, e),
             Multipart(e) => Multipart(e),
             Utf8(e) => Utf8(e),
+            Char(e) => Char(e),
             Int(e) => Int(e),
             Bool(e) => Bool(e),
             Float(e) => Float(e),
@@ -985,6 +990,7 @@ macro_rules! impl_from_for {
 
 impl_from_for!(<'a> Utf8Error => ErrorKind<'a> as Utf8);
 impl_from_for!(<'a> ParseIntError => ErrorKind<'a> as Int);
+impl_from_for!(<'a> ParseCharError => ErrorKind<'a> as Char);
 impl_from_for!(<'a> ParseFloatError => ErrorKind<'a> as Float);
 impl_from_for!(<'a> ParseBoolError => ErrorKind<'a> as Bool);
 impl_from_for!(<'a> AddrParseError => ErrorKind<'a> as Addr);
@@ -1024,6 +1030,7 @@ impl Entity {
             | ErrorKind::OutOfRange { .. }
             | ErrorKind::Validation { .. }
             | ErrorKind::Utf8(_)
+            | ErrorKind::Char(_)
             | ErrorKind::Int(_)
             | ErrorKind::Float(_)
             | ErrorKind::Bool(_)

core/lib/src/form/from_form.rs

@@ -103,7 +103,7 @@ use crate::http::uncased::AsUncased;
 /// `FromFormField`. Their behavior is documented in the table below.
 ///
 /// | Type                   | Strategy    | Default           | Data   | Value  | Notes                                              |
-/// |--------------------|-------------|-------------------|--------|--------|----------------------------------------------------|
+/// |------------------------|-------------|-------------------|--------|--------|----------------------------------------------------|
 /// | [`Strict<T>`]          | **strict**  | if `strict` `T`   | if `T` | if `T` | `T: FromForm`                                      |
 /// | [`Lenient<T>`]         | **lenient** | if `lenient` `T`  | if `T` | if `T` | `T: FromForm`                                      |
 /// | `Option<T>`            | **strict**  | `None`            | if `T` | if `T` | Infallible, `T: FromForm`                          |
@@ -111,6 +111,10 @@ use crate::http::uncased::AsUncased;
 /// | `Vec<T>`               | _inherit_   | `vec![]`          | if `T` | if `T` | `T: FromForm`                                      |
 /// | [`HashMap<K, V>`]      | _inherit_   | `HashMap::new()`  | if `V` | if `V` | `K: FromForm + Eq + Hash`, `V: FromForm`           |
 /// | [`BTreeMap<K, V>`]     | _inherit_   | `BTreeMap::new()` | if `V` | if `V` | `K: FromForm + Ord`, `V: FromForm`                 |
+/// | [`Range<T>`]           | _inherit_   | **no default**    | if `T` | if `T` | `T: FromForm`, expects `start`, `end` fields       |
+/// | [`RangeFrom<T>`]       | _inherit_   | **no default**    | if `T` | if `T` | `T: FromForm`, expects `start` field               |
+/// | [`RangeTo<T>`]         | _inherit_   | **no default**    | if `T` | if `T` | `T: FromForm`, expects `end` field                 |
+/// | [`RangeToInclusive<T>`]| _inherit_   | **no default**    | if `T` | if `T` | `T: FromForm`, expects `end` field                 |
 /// | `bool`                 | _inherit_   | `false`           | No     | Yes    | `"yes"/"on"/"true"`, `"no"/"off"/"false"`          |
 /// | (un)signed int         | _inherit_   | **no default**    | No     | Yes    | `{u,i}{size,8,16,32,64,128}`                       |
 /// | _nonzero_ int          | _inherit_   | **no default**    | No     | Yes    | `NonZero{I,U}{size,8,16,32,64,128}`                |
@@ -140,6 +144,10 @@ use crate::http::uncased::AsUncased;
 /// [`SocketAddr`]: std::net::SocketAddr
 /// [`SocketAddrV4`]: std::net::SocketAddrV4
 /// [`SocketAddrV6`]: std::net::SocketAddrV6
+/// [`Range<T>`]: https://doc.rust-lang.org/stable/std/ops/struct.Range.html
+/// [`RangeFrom<T>`]: https://doc.rust-lang.org/stable/std/ops/struct.RangeFrom.html
+/// [`RangeTo<T>`]: https://doc.rust-lang.org/stable/std/ops/struct.RangeTo.html
+/// [`RangeToInclusive<T>`]: https://doc.rust-lang.org/stable/std/ops/struct.RangeToInclusive.html
 ///
 /// ## Additional Notes
 ///
@@ -931,3 +939,51 @@ impl<'v, T: FromForm<'v> + Sync> FromForm<'v> for Arc<T> {
         T::finalize(this).map(Arc::new)
     }
 }
+
+macro_rules! impl_via_proxy {
+    ($R:ident => struct $T:ident <$($G:ident),*> { $($f:ident : $F:ident),* }) => {
+        const _: () = {
+            use super::*;
+
+            mod proxy {
+                #[derive(rocket::FromForm)]
+                pub struct $T<$($G),*> {
+                    $(pub $f : $F),*
+                }
+            }
+
+            #[crate::async_trait]
+            impl<'v, $($G: Send),*> FromForm<'v> for $R<$($G),*>
+                where proxy::$T<$($G),*>: FromForm<'v>
+            {
+                type Context = <proxy::$T<$($G),*> as FromForm<'v>>::Context;
+
+                fn init(opts: Options) -> Self::Context {
+                    <proxy::$T<$($G),*>>::init(opts)
+                }
+
+                fn push_value(ctxt: &mut Self::Context, field: ValueField<'v>) {
+                    <proxy::$T<$($G),*>>::push_value(ctxt, field)
+                }
+
+                async fn push_data(ctxt: &mut Self::Context, field: DataField<'v, '_>) {
+                    <proxy::$T<$($G),*>>::push_data(ctxt, field).await
+                }
+
+                fn finalize(this: Self::Context) -> Result<'v, Self> {
+                    let proxy = <proxy::$T<$($G),*>>::finalize(this)?;
+                    Ok($R {
+                        $($f : proxy.$f),*
+                    })
+                }
+            }
+        };
+    }
+}
+
+use std::ops::{Range, RangeFrom, RangeTo, RangeToInclusive};
+
+impl_via_proxy!(Range => struct Range<T> { start: T, end: T });
+impl_via_proxy!(RangeFrom => struct RangeFrom<T> { start: T });
+impl_via_proxy!(RangeTo => struct RangeTo<T> { end: T });
+impl_via_proxy!(RangeToInclusive => struct RangeToInclusive<T> { end: T });

core/lib/src/form/from_form_field.rs

@@ -391,6 +391,7 @@ macro_rules! impl_with_parse {
 }
 
 impl_with_parse!(
+    char,
     f32, f64,
     isize, i8, i16, i32, i64, i128,
     usize, u8, u16, u32, u64, u128,
@@ -398,7 +399,7 @@ impl_with_parse!(
     NonZeroUsize, NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU128,
     Ipv4Addr, IpAddr, Ipv6Addr, SocketAddrV4, SocketAddrV6, SocketAddr
 );
-//
+
 // Keep formats in sync with 'FromFormField' impls.
 static DATE_FMT: &[FormatItem<'_>] = format_description!("[year padding:none]-[month]-[day]");
 static TIME_FMT1: &[FormatItem<'_>] = format_description!("[hour padding:none]:[minute]:[second]");

core/lib/src/lib.rs

@@ -107,6 +107,9 @@
 //! [testing guide]: https://rocket.rs/master/guide/testing/#testing
 //! [Figment]: https://docs.rs/figment
 
+// Allows using Rocket's codegen in Rocket itself.
+extern crate self as rocket;
+
 /// These are public dependencies! Update docs if these are changed, especially
 /// figment's version number in docs.
 #[doc(hidden)]
@@ -149,11 +152,12 @@ pub mod tls;
 #[cfg_attr(nightly, doc(cfg(feature = "mtls")))]
 pub mod mtls;
 
+#[path = "rocket.rs"]
+mod rkt;
 mod util;
 mod server;
 mod lifecycle;
 mod state;
-mod rocket;
 mod router;
 mod phase;
 mod erased;
@@ -171,7 +175,7 @@ mod erased;
 #[doc(inline)] pub use crate::error::Error;
 #[doc(inline)] pub use crate::sentinel::Sentinel;
 #[doc(inline)] pub use crate::request::Request;
-#[doc(inline)] pub use crate::rocket::Rocket;
+#[doc(inline)] pub use crate::rkt::Rocket;
 #[doc(inline)] pub use crate::shutdown::Shutdown;
 #[doc(inline)] pub use crate::state::State;