Enum SpecCommandEffect 

pub enum SpecCommandEffect {
    Read,
    Write,
    Destructive,
}

What running a command does to the world.

This is a coarse, three-way classification rather than a permission model. It exists so a spec can distinguish “safe to run to find something out” from “changes state” from “may destroy something”, which is the distinction consumers keep reinventing:

• documentation and --help can mark destructive commands
• a shell wrapper can require confirmation
• an AI coding agent can be given an allowlist of read-only commands rather than asking about every invocation

It is deliberately not inherited by subcommands. git remote and git remote remove do different things, and silently inheriting an effect from a parent would make the strictest reading of a spec the wrong one.

Flags and arguments may carry an effect too, for commands whose danger depends on how they are invoked — pitchfork logs reads, pitchfork logs --clear deletes. A flag or argument can only ever raise the effect, never lower it, so a consumer that cannot parse the invocation may fall back to the maximum over the command and all of its flags and arguments and still be safe. --dry-run is the tempting counterexample; lowering is the dangerous direction, because a bug in the dry-run path would then be a spec that claims a command is safe when it is not. Ordered least to most dangerous, so Ord gives the combining rule: the effect of an invocation is the maximum of the command’s effect and the effect of every flag and argument actually supplied.

Variants

Read

Only inspects state. Running it twice is the same as running it once, and not running it changes nothing.

Write

Creates or modifies state, but does not remove anything the user cannot recreate by running another command.

Destructive

May delete or irreversibly overwrite something. Deserves a confirmation prompt.

Implementations

impl SpecCommandEffect

pub fn as_str(&self) -> &'static str

pub fn label(&self) -> &'static str

Human-readable label used in generated documentation.

Trait Implementations

impl Clone for SpecCommandEffect

fn clone(&self) -> SpecCommandEffect

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SpecCommandEffect

impl Debug for SpecCommandEffect

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for SpecCommandEffect

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Eq for SpecCommandEffect

impl FromStr for SpecCommandEffect

type Err = ParseError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<SpecCommandEffect, <Self as FromStr>::Err>

Parses a string s to return a value of this type.

impl Ord for SpecCommandEffect

fn cmp(&self, other: &SpecCommandEffect) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for SpecCommandEffect

fn eq(&self, other: &SpecCommandEffect) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for SpecCommandEffect

fn partial_cmp(&self, other: &SpecCommandEffect) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for SpecCommandEffect

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for SpecCommandEffect

impl TryFrom<&str> for SpecCommandEffect

type Error = ParseError

The type returned in the event of a conversion error.

fn try_from( s: &str, ) -> Result<SpecCommandEffect, <Self as TryFrom<&str>>::Error>

Performs the conversion.