fn parse()

in candle-core/src/npy.rs [102:195]
83 lines of code
17 McCabe index (conditional complexity)

    fn parse(header: &str) -> Result<Header> {
        let header =
            header.trim_matches(|c: char| c == '{' || c == '}' || c == ',' || c.is_whitespace());

        let mut parts: Vec<String> = vec![];
        let mut start_index = 0usize;
        let mut cnt_parenthesis = 0i64;
        for (index, c) in header.char_indices() {
            match c {
                '(' => cnt_parenthesis += 1,
                ')' => cnt_parenthesis -= 1,
                ',' => {
                    if cnt_parenthesis == 0 {
                        parts.push(header[start_index..index].to_owned());
                        start_index = index + 1;
                    }
                }
                _ => {}
            }
        }
        parts.push(header[start_index..].to_owned());
        let mut part_map: HashMap<String, String> = HashMap::new();
        for part in parts.iter() {
            let part = part.trim();
            if !part.is_empty() {
                match part.split(':').collect::<Vec<_>>().as_slice() {
                    [key, value] => {
                        let key = key.trim_matches(|c: char| c == '\'' || c.is_whitespace());
                        let value = value.trim_matches(|c: char| c == '\'' || c.is_whitespace());
                        let _ = part_map.insert(key.to_owned(), value.to_owned());
                    }
                    _ => return Err(Error::Npy(format!("unable to parse header {header}"))),
                }
            }
        }
        let fortran_order = match part_map.get("fortran_order") {
            None => false,
            Some(fortran_order) => match fortran_order.as_ref() {
                "False" => false,
                "True" => true,
                _ => return Err(Error::Npy(format!("unknown fortran_order {fortran_order}"))),
            },
        };
        let descr = match part_map.get("descr") {
            None => return Err(Error::Npy("no descr in header".to_string())),
            Some(descr) => {
                if descr.is_empty() {
                    return Err(Error::Npy("empty descr".to_string()));
                }
                if descr.starts_with('>') {
                    return Err(Error::Npy(format!("little-endian descr {descr}")));
                }
                // the only supported types in tensor are:
                //     float64, float32, float16,
                //     complex64, complex128,
                //     int64, int32, int16, int8,
                //     uint8, and bool.
                match descr.trim_matches(|c: char| c == '=' || c == '<' || c == '|') {
                    "e" | "f2" => DType::F16,
                    "f" | "f4" => DType::F32,
                    "d" | "f8" => DType::F64,
                    // "i" | "i4" => DType::S32,
                    "q" | "i8" => DType::I64,
                    // "h" | "i2" => DType::S16,
                    // "b" | "i1" => DType::S8,
                    "B" | "u1" => DType::U8,
                    "I" | "u4" => DType::U32,
                    "?" | "b1" => DType::U8,
                    // "F" | "F4" => DType::C64,
                    // "D" | "F8" => DType::C128,
                    descr => return Err(Error::Npy(format!("unrecognized descr {descr}"))),
                }
            }
        };
        let shape = match part_map.get("shape") {
            None => return Err(Error::Npy("no shape in header".to_string())),
            Some(shape) => {
                let shape = shape.trim_matches(|c: char| c == '(' || c == ')' || c == ',');
                if shape.is_empty() {
                    vec![]
                } else {
                    shape
                        .split(',')
                        .map(|v| v.trim().parse::<usize>())
                        .collect::<std::result::Result<Vec<_>, _>>()?
                }
            }
        };
        Ok(Header {
            descr,
            fortran_order,
            shape,
        })
    }