Enum ValueOrGlob 

pub enum ValueOrGlob<T> {
    Value(T),
    Glob(Glob),
}

Either a concrete value of type T or a wildcard Glob.

Every field on a generated selector struct is wrapped in this enum so that it can independently be pinned to a specific value or left as a glob to match anything. This is the core abstraction that allows selectors to express patterns like Read(Students.*) (specific table, any column) or Read(*.name) (any table, specific column).

The Default implementation returns Glob, matching the convention that an unspecified field matches everything.

Variants

Value(T)

A concrete, pinned value that this selector field must match exactly.

Glob(Glob)

A wildcard that matches any value for this selector field.

Implementations

impl<T> ValueOrGlob<T>

pub fn new_value(value: impl Into<T>) -> Self

Creates a ValueOrGlob::Value by converting the argument into T.

Accepts anything that implements Into<T> so callers can pass owned values, string slices (when T = String), and other convertible types without explicit conversion at the call site.

pub const fn new_glob() -> Self

Creates a ValueOrGlob::Glob, representing a wildcard that matches any value.

pub const fn is_value(&self) -> bool

Returns true if this is a concrete Value.

pub const fn is_glob(&self) -> bool

Returns true if this is a wildcard Glob.

pub const fn as_value(&self) -> Option<&T>

Returns a reference to the inner value if this is a Value, or None if it is a glob.

pub const fn as_glob(&self) -> Option<&Glob>

Returns a reference to the inner Glob if this is a Glob variant, or None if it is a value.

pub fn into_value(self) -> Option<T>

Consumes self and returns the inner T if this is a Value, or None if it is a glob.

pub fn into_glob(self) -> Option<Glob>

Consumes self and returns the inner Glob if this is a Glob variant, or None if it is a value.

Trait Implementations

impl<T: Clone> Clone for ValueOrGlob<T>

fn clone(&self) -> ValueOrGlob<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for ValueOrGlob<T>

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

Formats the value using the given formatter.

impl<T> Default for ValueOrGlob<T>

Defaults to ValueOrGlob::Glob so that omitted fields match everything.

fn default() -> Self

Returns the “default value” for a type.

impl<T> Display for ValueOrGlob<T>

where T: Display,

Delegates to the inner value’s Display for Value, or renders * for Glob.

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

Formats the value using the given formatter.

impl<T> From<Option<T>> for ValueOrGlob<T>

Converts an Option<T> into a ValueOrGlob: Some(v) becomes Value(v) and None becomes Glob, mirroring the semantics of “present means pinned, absent means match-all.”

fn from(value: Option<T>) -> Self

Converts to this type from the input type.

impl<T> From<ValueOrGlob<T>> for String

where T: Display,

Converts a ValueOrGlob to its string representation, enabling .into() at call sites that expect a String.

fn from(value: ValueOrGlob<T>) -> Self

Converts to this type from the input type.

impl<T> FromStr for ValueOrGlob<T>

where T: FromStr,

Parses "*" as a Glob and anything else by delegating to T::from_str, yielding a Value on success.

type Err = <T as FromStr>::Err

The associated error which can be returned from parsing.

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

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

impl<T: Hash> Hash for ValueOrGlob<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: Ord> Ord for ValueOrGlob<T>

fn cmp(&self, other: &ValueOrGlob<T>) -> 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<T: PartialEq> PartialEq for ValueOrGlob<T>

fn eq(&self, other: &ValueOrGlob<T>) -> 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<T: PartialOrd> PartialOrd for ValueOrGlob<T>

fn partial_cmp(&self, other: &ValueOrGlob<T>) -> 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<T> TryFrom<String> for ValueOrGlob<T>

where T: FromStr,

Parses an owned String into a ValueOrGlob by delegating to FromStr, enabling value.try_into() at call sites.

type Error = <T as FromStr>::Err

The type returned in the event of a conversion error.

fn try_from(value: String) -> Result<Self, Self::Error>

Performs the conversion.

impl<T: Copy> Copy for ValueOrGlob<T>

impl<T: Eq> Eq for ValueOrGlob<T>

impl<T> StructuralPartialEq for ValueOrGlob<T>