Enum FieldPred 

pub enum FieldPred {
    Eq(String, Value),
    Ne(String, Value),
    Gt(String, f64),
    Gte(String, f64),
    Lt(String, f64),
    Lte(String, f64),
    Contains(String, String),
    StartsWith(String, String),
    Exists(String, bool),
    IsNull(String, bool),
    In(String, Vec<Value>),
    Nin(String, Vec<Value>),
    EndsWith(String, String),
    Id(String),
    DatetimeComponent {
        field: String,
        which: u8,
        value: i64,
    },
    Type(String, String),
}

A single-field predicate inside a where expression.

Variants

Eq(String, Value)

$eq equality; $eq:null is an explicit alias for the is-null state predicate.

Ne(String, Value)

$ne inequality; the field must be present for the predicate to match.

Gt(String, f64)

$gt numeric/datetime strictly-greater comparison.

Gte(String, f64)

$gte numeric/datetime greater-than-or-equal comparison.

Lt(String, f64)

$lt numeric/datetime strictly-less comparison.

Lte(String, f64)

$lte numeric/datetime less-than-or-equal comparison.

Contains(String, String)

$contains case-insensitive substring match on a string.

StartsWith(String, String)

$startsWith case-insensitive prefix match on a string.

Exists(String, bool)

$exists presence test; the flag selects present (true) or absent.

IsNull(String, bool)

$isNull/$eq:null null-state test; the flag selects null (true) or non-null.

In(String, Vec<Value>)

$in membership against a set of literal values.

Nin(String, Vec<Value>)

$nin non-membership; the field must be present and match none of the values.

EndsWith(String, String)

$endsWith case-insensitive suffix match on a string.

Id(String)

$id — match the record identity itself.

DatetimeComponent

Datetime component predicate: { created: { $year: 2023 } }. which = 0..6 (year/month/day/hour/minute/second/millisecond).

Fields

field: String

Normalized property name the component is read from.

which: u8

Component selector: 0=year, 1=month, 2=day, 3=hour, 4=minute, 5=second, 6=millisecond.

value: i64

Expected component value.

Type(String, String)

$type operator: “string” | “number” | “boolean” | “array” | “object”

Trait Implementations

impl Clone for FieldPred

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldPred

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for FieldPred

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for FieldPred

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for FieldPred

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 FieldPred