Function compile_guard

core/src/compiler/top.rs:497–508

Compiles one loop guard expression to a temporary boolean register.

(
        ctx: &mut Context,
        symtable: &mut LocalSymtable<'_>,
        guard: Expr,
    )

fn compile_do(ctx: &mut Context, symtable: &mut LocalSymtable<'_>, span: DoSpan) -> Result<()> {
    /// Compiles one loop guard expression to a temporary boolean register.
    fn compile_guard(
        ctx: &mut Context,
        symtable: &mut LocalSymtable<'_>,
        guard: Expr,
    ) -> Result<(Register, LineCol)> {
        let guard_pos = guard.start_pos();
        let mut frozen = symtable.frozen();
        let mut scope = frozen.temp_scope();
        let reg = scope.alloc().map_err(|e| Error::from_syms(e, guard_pos))?;
        compile_expr_as_type(&mut ctx.codegen, &mut frozen, reg, guard, ExprType::Boolean)?;
        Ok((reg, guard_pos))
    }

    ctx.do_exit_stack.push(vec![]);