Method to_string

src/objects/string.rs:152–205

Convert the Python string data to a Rust string. For UTF-8 and ASCII-only latin-1, returns a borrow into the original string data. For Latin-1, UTF-16 and UTF-32, returns an owned string. Fails with UnicodeDecodeError if the string data isn't valid in its encoding.

(self, py: Python)

    ///
    /// Fails with UnicodeDecodeError if the string data isn't valid in its encoding.
    pub fn to_string(self, py: Python) -> PyResult<Cow<'a, str>> {
        match self {
            PyStringData::Utf8(data) => match str::from_utf8(data) {
                Ok(s) => Ok(Cow::Borrowed(s)),
                Err(e) => Err(PyErr::from_instance(
                    py,
                    exc::UnicodeDecodeError::new_utf8(py, data, e)?,
                )),
            },
            PyStringData::Latin1(data) => {
                if data.is_ascii() {
                    Ok(Cow::Borrowed(unsafe { str::from_utf8_unchecked(data) }))
                } else {
                    Ok(Cow::Owned(data.iter().map(|&b| b as char).collect()))
                }
            }
            PyStringData::Utf16(data) => {
                fn utf16_bytes(input: &[u16]) -> &[u8] {
                    unsafe { mem::transmute(input) }
                }
                match String::from_utf16(data) {
                    Ok(s) => Ok(Cow::Owned(s)),
                    Err(_) => Err(PyErr::from_instance(
                        py,
                        exc::UnicodeDecodeError::new(
                            py,
                            cstr!("utf-16"),
                            utf16_bytes(data),
                            0..2 * data.len(),
                            cstr!("invalid utf-16"),
                        )?,
                    )),
                }
            }
            PyStringData::Utf32(data) => {
                fn utf32_bytes(input: &[u32]) -> &[u8] {
                    unsafe { mem::transmute(input) }
                }
                match data.iter().map(|&u| char::from_u32(u)).collect() {
                    Some(s) => Ok(Cow::Owned(s)),
                    None => Err(PyErr::from_instance(
                        py,
                        exc::UnicodeDecodeError::new(
                            py,
                            cstr!("utf-32"),
                            utf32_bytes(data),
                            0..4 * data.len(),
                            cstr!("invalid utf-32"),
                        )?,
                    )),
                }
            }
        }
    }

    /// Convert the Python string data to a Rust string.
    ///