Enum FormulaExpr 

pub enum FormulaExpr {
    Constant {
        value: f64,
    },
    Variable {
        name: String,
    },
    Sum {
        left: Box<FormulaExpr>,
        right: Box<FormulaExpr>,
    },
    Sub {
        left: Box<FormulaExpr>,
        right: Box<FormulaExpr>,
    },
    Mul {
        left: Box<FormulaExpr>,
        right: Box<FormulaExpr>,
    },
    Div {
        left: Box<FormulaExpr>,
        right: Box<FormulaExpr>,
        by_zero_default: Option<f64>,
    },
    Neg {
        operand: Box<FormulaExpr>,
    },
    Abs {
        x: Box<FormulaExpr>,
    },
    Sqrt {
        x: Box<FormulaExpr>,
        domain_default: Option<f64>,
    },
    Log {
        x: Box<FormulaExpr>,
        domain_default: Option<f64>,
    },
    Ln {
        x: Box<FormulaExpr>,
        domain_default: Option<f64>,
    },
    Exp {
        x: Box<FormulaExpr>,
    },
    Acosh {
        x: Box<FormulaExpr>,
        domain_default: Option<f64>,
    },
    Pow {
        base: Box<FormulaExpr>,
        exponent: Box<FormulaExpr>,
    },
    Max {
        args: Vec<FormulaExpr>,
    },
    Min {
        args: Vec<FormulaExpr>,
    },
    GeoDistance {
        lat: f64,
        lon: f64,
        field: String,
    },
    Decay {
        kind: String,
        x: Box<FormulaExpr>,
        target: Option<Box<FormulaExpr>>,
        scale: Option<f64>,
        midpoint: Option<f64>,
    },
    Case {
        cond: Box<FilterExpr>,
        then_: Box<FormulaExpr>,
        else_: Box<FormulaExpr>,
    },
    MatchCondition {
        field: String,
        values: Vec<Value>,
    },
    Datetime {
        value: String,
    },
    DatetimeKey {
        key: String,
    },
}

Formula expression tree evaluated by QUERY FORMULA to rescore points.

Variants

Constant

Numeric literal.

Fields

value: f64

Literal numeric value.

Variable

Variable reference: $score, a DEFAULTS-bound name, or a datetime key.

Fields

name: String

Variable name, e.g. $score or a DEFAULTS key.

Sum

left + right.

Fields

left: Box<FormulaExpr>

Left operand.

right: Box<FormulaExpr>

Right operand.

Sub

left - right.

Fields

left: Box<FormulaExpr>

Left operand.

right: Box<FormulaExpr>

Right operand.

Mul

left * right.

Fields

left: Box<FormulaExpr>

Left operand.

right: Box<FormulaExpr>

Right operand.

Div

left / right, with optional [DEFAULT n] zero-division fallback.

Fields

left: Box<FormulaExpr>

Dividend.

right: Box<FormulaExpr>

Divisor.

by_zero_default: Option<f64>

Value substituted when the divisor is zero.

Neg

Unary negation.

Fields

operand: Box<FormulaExpr>

Expression to negate.

Abs

ABS(x).

Fields

x: Box<FormulaExpr>

Argument.

Sqrt

SQRT(x) with optional [DEFAULT n] negative fallback.

Fields

x: Box<FormulaExpr>

Argument.

domain_default: Option<f64>

Value substituted or clamped when x < 0.

Log

LOG(x) — base-10 logarithm with optional [DEFAULT n] non-positive fallback.

Fields

x: Box<FormulaExpr>

Argument.

domain_default: Option<f64>

Value substituted or clamped when x <= 0.

Ln

LN(x) — natural logarithm with optional [DEFAULT n] non-positive fallback.

Fields

x: Box<FormulaExpr>

Argument.

domain_default: Option<f64>

Value substituted or clamped when x <= 0.

Exp

EXP(x) — e raised to x.

Fields

x: Box<FormulaExpr>

Argument.

Acosh

ACOSH(x) — inverse hyperbolic cosine with optional [DEFAULT n] fallback.

Fields

x: Box<FormulaExpr>

Argument.

domain_default: Option<f64>

Value substituted or clamped when x < 1.

Pow

POW(base, exponent).

Fields

base: Box<FormulaExpr>

Base expression.

exponent: Box<FormulaExpr>

Exponent expression.

Max

N-ary MAX(...). At least one operand (parser-enforced).

Fields

args: Vec<FormulaExpr>

Folded operands (n >= 1).

Min

N-ary MIN(...). At least one operand (parser-enforced).

Fields

args: Vec<FormulaExpr>

Folded operands (n >= 1).

GeoDistance

GEO_DISTANCE(lat, lon, field) — meters between the coordinate and a geo field.

Fields

lat: f64

Query latitude in degrees.

lon: f64

Query longitude in degrees.

field: String

Payload geo field to measure against.

Decay

EXP_DECAY / GAUSS_DECAY / LIN_DECAY decay curve over x.

Fields

kind: String

Curve family: exp_decay, gauss_decay, or lin_decay.

x: Box<FormulaExpr>

Decaying expression, e.g. a datetime key or $score.

target: Option<Box<FormulaExpr>>

Decay origin; None defaults to zero.

scale: Option<f64>

Distance from target at which the output falls to midpoint.

midpoint: Option<f64>

Output value at that distance from target.

Case

CASE WHEN cond THEN then_ ELSE else_ END.

Fields

cond: Box<FilterExpr>

Boolean condition, evaluated as a filter.

then_: Box<FormulaExpr>

Value produced when the condition holds.

else_: Box<FormulaExpr>

Value produced otherwise.

MatchCondition

Inline MATCH(field, values) boolean used as a 0/1 condition.

Fields

field: String

Payload field to test.

values: Vec<Value>

Accepted values (any-of).

Datetime

DATETIME('…') — ISO 8601 datetime constant.

Fields

value: String

ISO 8601 datetime string.

DatetimeKey

DATETIME_KEY('field') — payload datetime field read as a datetime.

Fields

key: String

Payload datetime field name.

Trait Implementations

impl Clone for FormulaExpr

fn clone(&self) -> FormulaExpr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FormulaExpr

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

Formats the value using the given formatter.

impl PartialEq for FormulaExpr

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FormulaExpr