fn parse(value: &gltf::Value, ty: u32) -> Result<yagl::Data, ()> {
    use gltf::Value;
    use yagl::*;
    fn try_unwrap<T>(option: Option<T>) -> Result<T, ()> {
        match option {
            Some(item) => Ok(item),
            None => Err(()),
        }
    }

    let data = match ty {
        FLOAT => {
            match value.as_f64() {
                Some(v) => Data::F32(v as f32),
                None => return Err(()),
            }
        }
        FLOAT_MAT2 => {
            match value {
                &Value::Array(ref array) if array.len() >= 2 * 2 => {
                    Data::Mat2([[try_unwrap(array[0].as_f64())? as f32,
                                 try_unwrap(array[1].as_f64())? as f32],
                                [try_unwrap(array[2].as_f64())? as f32,
                                 try_unwrap(array[3].as_f64())? as f32]])
                }
                _ => return Err(()),
            }
        }
        FLOAT_MAT3 => {
            match value {
                &Value::Array(ref array) if array.len() >= 3 * 3 => {
                    Data::Mat3([[try_unwrap(array[0].as_f64())? as f32,
                                 try_unwrap(array[1].as_f64())? as f32,
                                 try_unwrap(array[2].as_f64())? as f32],
                                [try_unwrap(array[3].as_f64())? as f32,
                                 try_unwrap(array[4].as_f64())? as f32,
                                 try_unwrap(array[5].as_f64())? as f32],
                                [try_unwrap(array[6].as_f64())? as f32,
                                 try_unwrap(array[7].as_f64())? as f32,
                                 try_unwrap(array[8].as_f64())? as f32]])
                }
                _ => return Err(()),
            }
        }
        FLOAT_MAT4 => {
            match value {
                &Value::Array(ref array) if array.len() >= 4 * 4 => {
                    Data::Mat4([[try_unwrap(array[0].as_f64())? as f32,
                                 try_unwrap(array[1].as_f64())? as f32,
                                 try_unwrap(array[2].as_f64())? as f32,
                                 try_unwrap(array[3].as_f64())? as f32],
                                [try_unwrap(array[4].as_f64())? as f32,
                                 try_unwrap(array[5].as_f64())? as f32,
                                 try_unwrap(array[6].as_f64())? as f32,
                                 try_unwrap(array[7].as_f64())? as f32],
                                [try_unwrap(array[8].as_f64())? as f32,
                                 try_unwrap(array[9].as_f64())? as f32,
                                 try_unwrap(array[10].as_f64())? as f32,
                                 try_unwrap(array[11].as_f64())? as f32],
                                [try_unwrap(array[12].as_f64())? as f32,
                                 try_unwrap(array[13].as_f64())? as f32,
                                 try_unwrap(array[14].as_f64())? as f32,
                                 try_unwrap(array[15].as_f64())? as f32]])
                }
                _ => return Err(()),
            }
        }
        FLOAT_VEC2 => {
            match value {
                &Value::Array(ref array) if array.len() >= 3 => {
                    Data::Vec2([try_unwrap(array[0].as_f64())? as f32,
                                try_unwrap(array[1].as_f64())? as f32])
                }
                _ => return Err(()),
            }
        }
        FLOAT_VEC3 => {
            match value {
                &Value::Array(ref array) if array.len() >= 3 => {
                    Data::Vec3([try_unwrap(array[0].as_f64())? as f32,
                                try_unwrap(array[1].as_f64())? as f32,
                                try_unwrap(array[2].as_f64())? as f32])
                }
                _ => return Err(()),
            }
        }
        FLOAT_VEC4 => {
            match value {
                &Value::Array(ref array) if array.len() >= 4 => {
                    Data::Vec4([try_unwrap(array[0].as_f64())? as f32,
                                try_unwrap(array[1].as_f64())? as f32,
                                try_unwrap(array[2].as_f64())? as f32,
                                try_unwrap(array[3].as_f64())? as f32])
                }
                _ => return Err(()),
            }
        }
        _ => {
            println!("parse() implementation missing for {}", ty);
            panic!();
        }
    };

    Ok(data)
}