use thiserror::Error;
#[derive(Debug, Error, Clone, PartialEq)]
pub enum Error {
#[error("invalid input: {0}")]
InvalidInput(String),
#[error("singular Gram matrix: {0}")]
Singular(String),
}
pub type Result<T> = std::result::Result<T, Error>;
pub(crate) fn invalid<T>(msg: impl Into<String>) -> Result<T> {
Err(Error::InvalidInput(msg.into()))
}