Enum Term

pub enum Term<VS: VersionSet> {
    Positive(VS),
    Negative(VS),
}

A positive or negative expression regarding a set of versions.

Positive(r) and Negative(r.complement()) are not equivalent:

• the term Positive(r) is satisfied if the package is selected AND the selected version is in r.
• the term Negative(r.complement()) is satisfied if the package is not selected OR the selected version is in r.

A Positive term in the partial solution requires a version to be selected, but a Negative term allows for a solution that does not have that package selected. Specifically, Positive(VS::empty()) means that there was a conflict (we need to select a version for the package but can’t pick any), while Negative(VS::full()) would mean it is fine as long as we don’t select the package.

Variants

Positive(VS)

For example, 1.0.0 <= v < 2.0.0 is a positive expression that is evaluated true if a version is selected and comprised between version 1.0.0 and version 2.0.0.

Negative(VS)

The term not (v < 3.0.0) is a negative expression that is evaluated true if a version >= 3.0.0 is selected or if no version is selected at all.

Trait Implementations

impl<VS: VersionSet> AsRef<Term<VS>> for Term<VS>

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl<VS: Clone + VersionSet> Clone for Term<VS>

fn clone(&self) -> Term<VS>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<VS: Debug + VersionSet> Debug for Term<VS>

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

Formats the value using the given formatter.

impl<VS: VersionSet + Display> Display for Term<VS>

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

Formats the value using the given formatter.

impl<VS: PartialEq + VersionSet> PartialEq for Term<VS>

fn eq(&self, other: &Term<VS>) -> 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<VS: Eq + VersionSet> Eq for Term<VS>

impl<VS: VersionSet> StructuralPartialEq for Term<VS>