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#[derive(Clone, Copy)]
pub enum Mode {
Exec,
Eval,
Single,
BlockExpr,
}
impl std::str::FromStr for Mode {
type Err = ModeParseError;
fn from_str(s: &str) -> Result<Self, ModeParseError> {
match s {
"exec" => Ok(Mode::Exec),
"eval" => Ok(Mode::Eval),
"single" => Ok(Mode::Single),
_ => Err(ModeParseError { _priv: () }),
}
}
}
#[derive(Debug)]
pub struct ModeParseError {
_priv: (),
}
impl std::fmt::Display for ModeParseError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, r#"mode should be "exec", "eval", or "single""#)
}
}