loro/crates/loro-common/src/macros.rs
2024-02-18 17:27:33 +08:00

316 lines
10 KiB
Rust

/// A macro for creating `LoroValue`. It works just like the `json!` macro in
/// `serde_json`.
///
/// # Example
///
/// ```
/// use loro_common::loro_value;
/// loro_value!({
/// "name": "John",
/// "age": 12,
/// "collections": [
/// {
/// "binary-data": b"1,2,3"
/// }
/// ],
/// "float": 1.2,
/// "null": null,
/// "bool": true,
/// });
/// ```
///
#[macro_export(local_inner_macros)]
macro_rules! loro_value {
// Hide distracting implementation details from the generated rustdoc.
($($json:tt)+) => {
value_internal!($($json)+)
};
}
// Rocket relies on this because they export their own `json!` with a different
// doc comment than ours, and various Rust bugs prevent them from calling our
// `json!` from their `json!` so they call `value_internal!` directly. Check with
// @SergioBenitez before making breaking changes to this macro.
//
// Changes are fine as long as `value_internal!` does not call any new helper
// macros and can still be invoked as `value_internal!($($json)+)`.
#[macro_export(local_inner_macros)]
#[doc(hidden)]
macro_rules! value_internal {
//////////////////////////////////////////////////////////////////////////
// TT muncher for parsing the inside of an array [...]. Produces a vec![...]
// of the elements.
//
// Must be invoked as: value_internal!(@array [] $($tt)*)
//////////////////////////////////////////////////////////////////////////
// Done with trailing comma.
(@array [$($elems:expr,)*]) => {
json_internal_vec![$($elems,)*]
};
// Done without trailing comma.
(@array [$($elems:expr),*]) => {
json_internal_vec![$($elems),*]
};
// Next element is `null`.
(@array [$($elems:expr,)*] null $($rest:tt)*) => {
value_internal!(@array [$($elems,)* value_internal!(null)] $($rest)*)
};
// Next element is `true`.
(@array [$($elems:expr,)*] true $($rest:tt)*) => {
value_internal!(@array [$($elems,)* value_internal!(true)] $($rest)*)
};
// Next element is `false`.
(@array [$($elems:expr,)*] false $($rest:tt)*) => {
value_internal!(@array [$($elems,)* value_internal!(false)] $($rest)*)
};
// Next element is an array.
(@array [$($elems:expr,)*] [$($array:tt)*] $($rest:tt)*) => {
value_internal!(@array [$($elems,)* value_internal!([$($array)*])] $($rest)*)
};
// Next element is a map.
(@array [$($elems:expr,)*] {$($map:tt)*} $($rest:tt)*) => {
value_internal!(@array [$($elems,)* value_internal!({$($map)*})] $($rest)*)
};
// Next element is an expression followed by comma.
(@array [$($elems:expr,)*] $next:expr, $($rest:tt)*) => {
value_internal!(@array [$($elems,)* value_internal!($next),] $($rest)*)
};
// Last element is an expression with no trailing comma.
(@array [$($elems:expr,)*] $last:expr) => {
value_internal!(@array [$($elems,)* value_internal!($last)])
};
// Comma after the most recent element.
(@array [$($elems:expr),*] , $($rest:tt)*) => {
value_internal!(@array [$($elems,)*] $($rest)*)
};
// Unexpected token after most recent element.
(@array [$($elems:expr),*] $unexpected:tt $($rest:tt)*) => {
json_unexpected!($unexpected)
};
//////////////////////////////////////////////////////////////////////////
// TT muncher for parsing the inside of an object {...}. Each entry is
// inserted into the given map variable.
//
// Must be invoked as: value_internal!(@object $map () ($($tt)*) ($($tt)*))
//
// We require two copies of the input tokens so that we can match on one
// copy and trigger errors on the other copy.
//////////////////////////////////////////////////////////////////////////
// Done.
(@object $object:ident () () ()) => {};
// Insert the current entry followed by trailing comma.
(@object $object:ident [$($key:tt)+] ($value:expr) , $($rest:tt)*) => {
let _ = $object.insert(($($key)+).into(), $value);
value_internal!(@object $object () ($($rest)*) ($($rest)*));
};
// Current entry followed by unexpected token.
(@object $object:ident [$($key:tt)+] ($value:expr) $unexpected:tt $($rest:tt)*) => {
json_unexpected!($unexpected);
};
// Insert the last entry without trailing comma.
(@object $object:ident [$($key:tt)+] ($value:expr)) => {
let _ = $object.insert(($($key)+).into(), $value);
};
// Next value is `null`.
(@object $object:ident ($($key:tt)+) (: null $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!(null)) $($rest)*);
};
// Next value is `true`.
(@object $object:ident ($($key:tt)+) (: true $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!(true)) $($rest)*);
};
// Next value is `false`.
(@object $object:ident ($($key:tt)+) (: false $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!(false)) $($rest)*);
};
// Next value is an array.
(@object $object:ident ($($key:tt)+) (: [$($array:tt)*] $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!([$($array)*])) $($rest)*);
};
// Next value is a map.
(@object $object:ident ($($key:tt)+) (: {$($map:tt)*} $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!({$($map)*})) $($rest)*);
};
// Next value is an expression followed by comma.
(@object $object:ident ($($key:tt)+) (: $value:expr , $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!($value)) , $($rest)*);
};
// Last value is an expression with no trailing comma.
(@object $object:ident ($($key:tt)+) (: $value:expr) $copy:tt) => {
value_internal!(@object $object [$($key)+] (value_internal!($value)));
};
// Missing value for last entry. Trigger a reasonable error message.
(@object $object:ident ($($key:tt)+) (:) $copy:tt) => {
// "unexpected end of macro invocation"
value_internal!();
};
// Missing colon and value for last entry. Trigger a reasonable error
// message.
(@object $object:ident ($($key:tt)+) () $copy:tt) => {
// "unexpected end of macro invocation"
value_internal!();
};
// Misplaced colon. Trigger a reasonable error message.
(@object $object:ident () (: $($rest:tt)*) ($colon:tt $($copy:tt)*)) => {
// Takes no arguments so "no rules expected the token `:`".
json_unexpected!($colon);
};
// Found a comma inside a key. Trigger a reasonable error message.
(@object $object:ident ($($key:tt)*) (, $($rest:tt)*) ($comma:tt $($copy:tt)*)) => {
// Takes no arguments so "no rules expected the token `,`".
json_unexpected!($comma);
};
// Key is fully parenthesized. This avoids clippy double_parens false
// positives because the parenthesization may be necessary here.
(@object $object:ident () (($key:expr) : $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object ($key) (: $($rest)*) (: $($rest)*));
};
// Refuse to absorb colon token into key expression.
(@object $object:ident ($($key:tt)*) (: $($unexpected:tt)+) $copy:tt) => {
json_expect_expr_comma!($($unexpected)+);
};
// Munch a token into the current key.
(@object $object:ident ($($key:tt)*) ($tt:tt $($rest:tt)*) $copy:tt) => {
value_internal!(@object $object ($($key)* $tt) ($($rest)*) ($($rest)*));
};
//////////////////////////////////////////////////////////////////////////
// The main implementation.
//
// Must be invoked as: value_internal!($($json)+)
//////////////////////////////////////////////////////////////////////////
(null) => {
$crate::LoroValue::Null
};
(true) => {
$crate::LoroValue::Bool(true)
};
(false) => {
$crate::LoroValue::Bool(false)
};
([]) => {
$crate::LoroValue::List(std::sync::Arc::new(json_internal_vec![]))
};
([ $($tt:tt)+ ]) => {
$crate::LoroValue::List(std::sync::Arc::new(value_internal!(@array [] $($tt)+)))
};
({}) => {
$crate::LoroValue::Map(std::sync::Arc::new(Default::default()))
};
({ $($tt:tt)+ }) => {
({
let mut object = $crate::FxHashMap::default();
value_internal!(@object object () ($($tt)+) ($($tt)+));
$crate::LoroValue::Map(std::sync::Arc::new(object))
})
};
// Any Serialize type: numbers, strings, struct literals, variables etc.
// Must be below every other rule.
($other:expr) => {
$crate::to_value($other)
};
}
#[macro_export]
#[doc(hidden)]
macro_rules! json_unexpected {
() => {};
}
// The json_internal macro above cannot invoke vec directly because it uses
// local_inner_macros. A vec invocation there would resolve to $crate::vec.
// Instead invoke vec here outside of local_inner_macros.
#[macro_export]
#[doc(hidden)]
macro_rules! json_internal_vec {
($($content:tt)*) => {
vec![$($content)*]
};
}
#[cfg(test)]
mod test {
#[test]
fn test_value_macro() {
let v = loro_value!([1, 2, 3]);
let list = v.into_list().unwrap();
assert_eq!(&*list, &[1.into(), 2.into(), 3.into()]);
let map = loro_value!({
"hi": true,
"false": false,
"null": null,
"list": [],
"integer": 123,
"float": 123.123,
"map": {
"a": "1"
},
"binary": b"123",
});
let map = map.into_map().unwrap();
assert_eq!(map.len(), 8);
assert!(*map.get("hi").unwrap().as_bool().unwrap());
assert!(!(*map.get("false").unwrap().as_bool().unwrap()));
assert!(map.get("null").unwrap().is_null());
assert_eq!(map.get("list").unwrap().as_list().unwrap().len(), 0);
assert_eq!(*map.get("integer").unwrap().as_i64().unwrap(), 123);
assert_eq!(*map.get("float").unwrap().as_double().unwrap(), 123.123);
assert_eq!(map.get("map").unwrap().as_map().unwrap().len(), 1);
assert_eq!(
&**map
.get("map")
.unwrap()
.as_map()
.unwrap()
.get("a")
.unwrap()
.as_string()
.unwrap(),
"1"
);
assert_eq!(
&**map.get("binary").unwrap().as_binary().unwrap(),
&b"123".to_vec()
);
}
}