nil/src/source.rs

use std::sync::Arc;
use syntax::Parse;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct FileId(pub u32);

#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
pub struct InFile<T> {
    pub file_id: FileId,
    pub value: T,
}

impl<T> InFile<T> {
    pub fn new(file_id: FileId, value: T) -> Self {
        Self { file_id, value }
    }

    pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> InFile<U> {
        InFile {
            file_id: self.file_id,
            value: f(self.value),
        }
    }
}

#[salsa::query_group(SourceDatabaseStorage)]
pub trait SourceDatabase {
    #[salsa::input]
    fn file_source_root(&self) -> FileId;

    #[salsa::input]
    fn file_content(&self, file_id: FileId) -> Arc<[u8]>;

    fn parse(&self, file_id: FileId) -> InFile<Parse>;
}

fn parse(db: &dyn SourceDatabase, file_id: FileId) -> InFile<Parse> {
    let content = db.file_content(file_id);
    let content = std::str::from_utf8(&content).unwrap_or_default();
    let parse = syntax::parse_file(content);
    InFile::new(file_id, parse)
}