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use super::InitExpr;
use crate::{errors::ModuleError, GlobalType};
/// The index of a global variable within a [`Module`].
///
/// [`Module`]: [`super::Module`]
#[derive(Debug, Copy, Clone)]
pub struct GlobalIdx(pub(crate) u32);
impl GlobalIdx {
/// Returns the [`GlobalIdx`] as `u32`.
pub fn into_u32(self) -> u32 {
self.0
}
/// Returns the [`GlobalIdx`] as `usize`.
pub fn into_usize(self) -> usize {
self.0 as usize
}
}
/// A global variable definition within a [`Module`].
///
/// [`Module`]: [`super::Module`]
#[derive(Debug)]
pub struct Global {
/// The type of the global variable.
global_type: GlobalType,
/// The initial value of the global variable.
///
/// # Note
///
/// This is represented by a so called initializer expression
/// that is run at module instantiation time.
init_expr: InitExpr,
}
impl TryFrom<wasmparser::Global<'_>> for Global {
type Error = ModuleError;
fn try_from(global: wasmparser::Global<'_>) -> Result<Self, Self::Error> {
let global_type = global.ty.try_into()?;
let init_expr = InitExpr::new(global.init_expr);
Ok(Global {
global_type,
init_expr,
})
}
}
impl Global {
/// Splits the [`Global`] into its global type and its global initializer.
pub fn into_type_and_init(self) -> (GlobalType, InitExpr) {
(self.global_type, self.init_expr)
}
}