oxc/crates/oxc_syntax/src/reference.rs

use bitflags::bitflags;
use oxc_index::define_index_type;

define_index_type! {
    pub struct ReferenceId = u32;
}

bitflags! {
    #[derive(Debug, Default, Clone, Copy, Eq, PartialEq)]
    pub struct ReferenceFlag: u8 {
        const None = 0;
        const Read = 1 << 0;
        const Write = 1 << 1;
        const ReadWrite = Self::Read.bits() | Self::Write.bits();
    }
}

impl ReferenceFlag {
    pub const fn read() -> Self {
        Self::Read
    }

    pub const fn write() -> Self {
        Self::Write
    }

    pub const fn read_write() -> Self {
        Self::ReadWrite
    }

    /// The identifier is read from. It may also be written to.
    pub const fn is_read(&self) -> bool {
        self.intersects(Self::Read)
    }

    /// The identifier is only read from.
    pub const fn is_read_only(&self) -> bool {
        self.contains(Self::Read)
    }

    /// The identifier is written to. It may also be read from.
    pub const fn is_write(&self) -> bool {
        self.intersects(Self::Write)
    }

    /// The identifier is only written to. It is not read from in this reference.
    pub const fn is_write_only(&self) -> bool {
        self.contains(Self::Write)
    }

    /// The identifier is both read from and written to, e.g `a += 1`.
    pub const fn is_read_write(&self) -> bool {
        self.contains(Self::ReadWrite)
    }
}