Jonas Platte f540bbbc99
events: Remove some accessor functions
They will no longer make sense with the new enum hierarchy.
2022-04-05 14:29:17 +02:00

299 lines
11 KiB
Rust

//! Implementation of event enum and event content enum macros.
use std::fmt;
use proc_macro2::Span;
use quote::{format_ident, IdentFragment};
use syn::{
braced,
parse::{self, Parse, ParseStream},
Attribute, Ident, LitStr, Token,
};
/// Custom keywords for the `event_enum!` macro
mod kw {
syn::custom_keyword!(kind);
syn::custom_keyword!(events);
}
// If the variants of this enum change `to_event_path` needs to be updated as well.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum EventKindVariation {
None,
Sync,
Original,
OriginalSync,
Stripped,
Initial,
Redacted,
RedactedSync,
}
impl fmt::Display for EventKindVariation {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
EventKindVariation::None => write!(f, ""),
EventKindVariation::Sync => write!(f, "Sync"),
EventKindVariation::Original => write!(f, "Original"),
EventKindVariation::OriginalSync => write!(f, "OriginalSync"),
EventKindVariation::Stripped => write!(f, "Stripped"),
EventKindVariation::Initial => write!(f, "Initial"),
EventKindVariation::Redacted => write!(f, "Redacted"),
EventKindVariation::RedactedSync => write!(f, "RedactedSync"),
}
}
}
impl EventKindVariation {
pub fn is_redacted(self) -> bool {
matches!(self, Self::Redacted | Self::RedactedSync)
}
pub fn is_sync(self) -> bool {
matches!(self, Self::OriginalSync | Self::RedactedSync)
}
pub fn to_redacted(self) -> Self {
match self {
EventKindVariation::Original => EventKindVariation::Redacted,
EventKindVariation::OriginalSync => EventKindVariation::RedactedSync,
_ => panic!("No redacted form of {:?}", self),
}
}
pub fn to_sync(self) -> Self {
match self {
EventKindVariation::Original => EventKindVariation::OriginalSync,
EventKindVariation::Redacted => EventKindVariation::RedactedSync,
_ => panic!("No sync form of {:?}", self),
}
}
pub fn to_full(self) -> Self {
match self {
EventKindVariation::OriginalSync => EventKindVariation::Original,
EventKindVariation::RedactedSync => EventKindVariation::Redacted,
_ => panic!("No original (unredacted) form of {:?}", self),
}
}
}
// If the variants of this enum change `to_event_path` needs to be updated as well.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum EventKind {
GlobalAccountData,
RoomAccountData,
Ephemeral,
MessageLike,
State,
ToDevice,
RoomRedaction,
Presence,
HierarchySpaceChild,
Decrypted,
}
impl fmt::Display for EventKind {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
EventKind::GlobalAccountData => write!(f, "GlobalAccountDataEvent"),
EventKind::RoomAccountData => write!(f, "RoomAccountDataEvent"),
EventKind::Ephemeral => write!(f, "EphemeralRoomEvent"),
EventKind::MessageLike => write!(f, "MessageLikeEvent"),
EventKind::State => write!(f, "StateEvent"),
EventKind::ToDevice => write!(f, "ToDeviceEvent"),
EventKind::RoomRedaction => write!(f, "RoomRedactionEvent"),
EventKind::Presence => write!(f, "PresenceEvent"),
EventKind::HierarchySpaceChild => write!(f, "HierarchySpaceChildEvent"),
EventKind::Decrypted => unreachable!(),
}
}
}
impl IdentFragment for EventKind {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
impl IdentFragment for EventKindVariation {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
impl EventKind {
pub fn is_account_data(self) -> bool {
matches!(self, Self::GlobalAccountData | Self::RoomAccountData)
}
pub fn is_room(self) -> bool {
matches!(self, Self::MessageLike | Self::RoomRedaction | Self::State)
}
pub fn to_event_ident(self, var: EventKindVariation) -> syn::Result<Ident> {
use EventKindVariation as V;
match (self, var) {
(
Self::GlobalAccountData
| Self::RoomAccountData
| Self::Ephemeral
| Self::ToDevice
| Self::Presence
| Self::HierarchySpaceChild
| Self::Decrypted,
V::None,
)
| (Self::Ephemeral, V::Sync)
| (
Self::MessageLike | Self::RoomRedaction | Self::State,
V::Original | V::OriginalSync | V::Redacted | V::RedactedSync,
)
| (Self::State, V::Stripped | V::Initial) => Ok(format_ident!("{}{}", var, self)),
_ => Err(syn::Error::new(
Span::call_site(),
format!(
"({:?}, {:?}) is not a valid event kind / variation combination",
self, var
),
)),
}
}
pub fn to_event_enum_ident(self, var: EventKindVariation) -> syn::Result<Ident> {
Ok(format_ident!("Any{}", self.to_event_ident(var)?))
}
pub fn to_event_type_enum(self) -> Ident {
format_ident!("{}Type", self)
}
/// `Any[kind]EventContent`
pub fn to_content_enum(self) -> Ident {
format_ident!("Any{}Content", self)
}
}
impl Parse for EventKind {
fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
let ident: Ident = input.parse()?;
Ok(match ident.to_string().as_str() {
"GlobalAccountData" => EventKind::GlobalAccountData,
"RoomAccountData" => EventKind::RoomAccountData,
"EphemeralRoom" => EventKind::Ephemeral,
"MessageLike" => EventKind::MessageLike,
"State" => EventKind::State,
"ToDevice" => EventKind::ToDevice,
id => {
return Err(syn::Error::new_spanned(
ident,
format!(
"valid event kinds are GlobalAccountData, RoomAccountData, EphemeralRoom, \
MessageLike, State, ToDevice found `{}`",
id
),
));
}
})
}
}
// This function is only used in the `Event` derive macro expansion code.
/// Validates the given `ident` is a valid event struct name and returns a tuple of enums
/// representing the name.
pub fn to_kind_variation(ident: &Ident) -> Option<(EventKind, EventKindVariation)> {
let ident_str = ident.to_string();
match ident_str.as_str() {
"GlobalAccountDataEvent" => Some((EventKind::GlobalAccountData, EventKindVariation::None)),
"RoomAccountDataEvent" => Some((EventKind::RoomAccountData, EventKindVariation::None)),
"EphemeralRoomEvent" => Some((EventKind::Ephemeral, EventKindVariation::None)),
"SyncEphemeralRoomEvent" => Some((EventKind::Ephemeral, EventKindVariation::Sync)),
"OriginalMessageLikeEvent" => Some((EventKind::MessageLike, EventKindVariation::Original)),
"OriginalSyncMessageLikeEvent" => {
Some((EventKind::MessageLike, EventKindVariation::OriginalSync))
}
"RedactedMessageLikeEvent" => Some((EventKind::MessageLike, EventKindVariation::Redacted)),
"RedactedSyncMessageLikeEvent" => {
Some((EventKind::MessageLike, EventKindVariation::RedactedSync))
}
"OriginalStateEvent" => Some((EventKind::State, EventKindVariation::Original)),
"OriginalSyncStateEvent" => Some((EventKind::State, EventKindVariation::OriginalSync)),
"StrippedStateEvent" => Some((EventKind::State, EventKindVariation::Stripped)),
"InitialStateEvent" => Some((EventKind::State, EventKindVariation::Initial)),
"RedactedStateEvent" => Some((EventKind::State, EventKindVariation::Redacted)),
"RedactedSyncStateEvent" => Some((EventKind::State, EventKindVariation::RedactedSync)),
"ToDeviceEvent" => Some((EventKind::ToDevice, EventKindVariation::None)),
"PresenceEvent" => Some((EventKind::Presence, EventKindVariation::None)),
"HierarchySpaceChildEvent" => {
Some((EventKind::HierarchySpaceChild, EventKindVariation::Stripped))
}
"OriginalRoomRedactionEvent" => Some((EventKind::RoomRedaction, EventKindVariation::None)),
"OriginalSyncRoomRedactionEvent" => {
Some((EventKind::RoomRedaction, EventKindVariation::OriginalSync))
}
"RedactedRoomRedactionEvent" => {
Some((EventKind::RoomRedaction, EventKindVariation::Redacted))
}
"RedactedSyncRoomRedactionEvent" => {
Some((EventKind::RoomRedaction, EventKindVariation::RedactedSync))
}
"DecryptedOlmV1Event" | "DecryptedMegolmV1Event" => {
Some((EventKind::Decrypted, EventKindVariation::None))
}
_ => None,
}
}
pub struct EventEnumEntry {
pub attrs: Vec<Attribute>,
pub ev_type: LitStr,
}
impl Parse for EventEnumEntry {
fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
Ok(Self { attrs: input.call(Attribute::parse_outer)?, ev_type: input.parse()? })
}
}
/// The entire `event_enum!` macro structure directly as it appears in the source code.
pub struct EventEnumDecl {
/// Outer attributes on the field, such as a docstring.
pub attrs: Vec<Attribute>,
/// The event kind.
pub kind: EventKind,
/// An array of valid matrix event types.
///
/// This will generate the variants of the event type "kind". There needs to be a corresponding
/// variant in `ruma_common::events::EventType` for this event (converted to a valid Rust-style
/// type name by stripping `m.`, replacing the remaining dots by underscores and then
/// converting from snake_case to CamelCase).
pub events: Vec<EventEnumEntry>,
}
/// The entire `event_enum!` macro structure directly as it appears in the source code.
pub struct EventEnumInput {
pub(crate) enums: Vec<EventEnumDecl>,
}
impl Parse for EventEnumInput {
fn parse(input: ParseStream<'_>) -> parse::Result<Self> {
let mut enums = vec![];
while !input.is_empty() {
let attrs = input.call(Attribute::parse_outer)?;
let _: Token![enum] = input.parse()?;
let kind: EventKind = input.parse()?;
let content;
braced!(content in input);
let events = content.parse_terminated::<_, Token![,]>(EventEnumEntry::parse)?;
let events = events.into_iter().collect();
enums.push(EventEnumDecl { attrs, kind, events });
}
Ok(EventEnumInput { enums })
}
}