Function template

crates/vm/src/stdlib/_sre.rs:140–165

(
        _pattern: PyObjectRef,
        template: PyListRef,
        vm: &VirtualMachine,
    )

    #[pyfunction]
    fn template(
        _pattern: PyObjectRef,
        template: PyListRef,
        vm: &VirtualMachine,
    ) -> PyResult<Template> {
        let err = || vm.new_type_error("invalid template");

        let mut items = Vec::with_capacity(1);
        let v = template.borrow_vec();
        let literal = v.first().ok_or_else(err)?.clone();
        let trunks = v[1..].chunks_exact(2);

        if !trunks.remainder().is_empty() {
            return Err(err());
        }

        for trunk in trunks {
            let index: usize = trunk[0]
                .downcast_ref::<PyInt>()
                .ok_or_else(|| vm.new_type_error("expected usize"))?
                .try_to_primitive(vm)?;
            items.push((index, trunk[1].clone()));
        }

        Ok(Template { literal, items })
    }

    #[derive(FromArgs)]
    struct StringArgs {