Enum Capability 

pub enum Capability {
    None,
    Palette16,
    Palette256,
    TrueColor,
}

Terminal color capability detected from the environment. Truecolor is preferred when available; None strips all color and keeps only decorations.

Variants are ordered richest→poorest so cap >= Capability::Palette256 reads “at least 256 colors.” Downgrade logic can branch on ordering rather than re-matching the ladder each time.

Variants

None

Palette16

Palette256

TrueColor

Implementations

impl Capability

pub fn detect() -> Self

Detect honoring NO_COLOR (per no-color.org). Kept for callers that want a single-shot detect without threading the env through a precedence chain.

pub fn from_terminal() -> Self

Raw terminal capability from supports-color, ignoring NO_COLOR. The color-policy precedence chain uses this so a --force-color flag can outrank the env var. Returns None when stdout isn’t a TTY so color = "auto" stays plain-text under pipes and redirects.

pub fn from_env_vars(colorterm: Option<&str>, term: Option<&str>) -> Self

Env-only capability probe from the COLORTERM and TERM values carried on CliEnv. Used by the force-color path to recover a tier when supports-color gives up (e.g. piped stdout under Claude Code). Never reads the live process env; callers must snapshot into CliEnv::from_process first so tests and embedders stay hermetic.

Returns None for TERM=dumb, empty TERM, or no TERM at all.

pub fn force_from(tty: Self, env: Self) -> Self

Combine a TTY probe (from supports-color) and an env probe (from COLORTERM / TERM) into a capability under force-color intent. Picks the richer of the two, flooring at Palette16 so an explicit color = "always" / --force-color / FORCE_COLOR never collapses to no-color. The Palette16 floor overrides TERM=dumb — the user explicitly asked for color, so a dumb terminal signal loses.

Trait Implementations

impl Clone for Capability

fn clone(&self) -> Capability

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Capability

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

Formats the value using the given formatter.

impl Ord for Capability

fn cmp(&self, other: &Capability) -> 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 Capability

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Capability

fn partial_cmp(&self, other: &Capability) -> 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 Copy for Capability

impl Eq for Capability

impl StructuralPartialEq for Capability