forked from M-Labs/nac3
41 lines
921 B
Rust
41 lines
921 B
Rust
|
use crate::token::Tok;
|
||
|
|
|
||
|
|
#[derive(Clone, Copy)]
|
||
|
|
pub enum Mode {
|
||
|
|
Module,
|
||
|
|
Interactive,
|
||
|
|
Expression,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl Mode {
|
||
|
|
pub(crate) fn to_marker(self) -> Tok {
|
||
|
|
match self {
|
||
|
|
Self::Module => Tok::StartModule,
|
||
|
|
Self::Interactive => Tok::StartInteractive,
|
||
|
|
Self::Expression => Tok::StartExpression,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl std::str::FromStr for Mode {
|
||
|
|
type Err = ModeParseError;
|
||
|
|
fn from_str(s: &str) -> Result<Self, ModeParseError> {
|
||
|
|
match s {
|
||
|
|
"exec" | "single" => Ok(Mode::Module),
|
||
|
|
"eval" => Ok(Mode::Expression),
|
||
|
|
_ => 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""#)
|
||
|
|
}
|
||
|
|
}
|