Method swapcase

crates/vm/src/builtins/str.rs:1041–1055

(&self)

    #[pymethod]
    fn swapcase(&self) -> Wtf8Buf {
        let mut swapped_str = Wtf8Buf::with_capacity(self.data.len());
        for c_orig in self.as_wtf8().code_points() {
            let c = c_orig.to_char_lossy();
            // to_uppercase returns an iterator, to_ascii_uppercase returns the char
            if c.is_lowercase() {
                swapped_str.push_char(c.to_ascii_uppercase());
            } else if c.is_uppercase() {
                swapped_str.push_char(c.to_ascii_lowercase());
            } else {
                swapped_str.push(c_orig);
            }
        }
        swapped_str
    }

    #[pymethod]
    fn isalpha(&self) -> bool {