ruff/core/src/mode.rs

63 lines
2.7 KiB
Rust

//! Control in the different modes by which a source file can be parsed.
/// The mode argument specifies in what way code must be parsed.
#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
pub enum Mode {
/// The code consists of a sequence of statements.
Module,
/// The code consists of a sequence of interactive statement.
Interactive,
/// The code consists of a single expression.
Expression,
/// The code consists of a sequence of statements which are part of a
/// Jupyter Notebook and thus could include escape commands scoped to
/// a single line.
///
/// ## Limitations:
///
/// These escaped commands are only supported when they are the only
/// statement on a line. If they're part of a larger statement such as
/// on the right-hand side of an assignment, the lexer will not recognize
/// them as escape commands.
///
/// For [Dynamic object information], the escape characters (`?`, `??`)
/// must be used before an object. For example, `?foo` will be recognized,
/// but `foo?` will not.
///
/// ## Supported escape commands:
/// - [Magic command system] which is limited to [line magics] and can start
/// with `?` or `??`.
/// - [Dynamic object information] which can start with `?` or `??`.
/// - [System shell access] which can start with `!` or `!!`.
/// - [Automatic parentheses and quotes] which can start with `/`, `;`, or `,`.
///
/// [Magic command system]: https://ipython.readthedocs.io/en/stable/interactive/reference.html#magic-command-system
/// [line magics]: https://ipython.readthedocs.io/en/stable/interactive/magics.html#line-magics
/// [Dynamic object information]: https://ipython.readthedocs.io/en/stable/interactive/reference.html#dynamic-object-information
/// [System shell access]: https://ipython.readthedocs.io/en/stable/interactive/reference.html#system-shell-access
/// [Automatic parentheses and quotes]: https://ipython.readthedocs.io/en/stable/interactive/reference.html#automatic-parentheses-and-quotes
Jupyter,
}
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),
"jupyter" => Ok(Mode::Jupyter),
_ => Err(ModeParseError),
}
}
}
/// Returned when a given mode is not valid.
#[derive(Debug)]
pub struct ModeParseError;
impl std::fmt::Display for ModeParseError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, r#"mode must be "exec", "eval", "jupyter", or "single""#)
}
}