Ranking signal supported operations

Index Version Requirements: v2.0.0+

List of operations supported in the ranking_expr="<your-expression>" syntax.

The explanation on how to use ranking signals is available here.

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Operation	Type	Description / Examples
uncalibrated_relevance	Float	the unmodified relevance score of the object
object.<property>	Any	the value of `<property>` for the object as defined in the object store. Nested fields can be accessed with the dot notation e.g. `object.a.b.c`
NOW	Float	the current timestamp in unix time (seconds)
timestamp(<timestamp>)	Float	function to convert a RFC 3339 `<timestamp>`

Important: The relevance is "uncalibrated" and is only meant to compare objects. The value does not have an intrinsic meaning; its distribution and bounds can vary depending on the evaluation method. We advise against using its value as a cutoff.

Operators

Operator	Description
^	Exponentiation
*	Product
/	Division (integer if both arguments are integers, otherwise float)
%	Modulo (integer if both arguments are integers, otherwise float)
+	Sum or String Concatenation
-	Difference
`<`	Lower than
`>`	Greater than
`<=`	Lower than or equal
>=	Greater than or equal
==	Equal
!=	Not equal
&&	Logical and
\|\|	Logical or
-	Negation
!	Logical not
,	Aggregation
;	Expression Chaining

Operators: Variables and Assignment

Operator	Description
=	Assignment
+=	Sum-Assignment or String-Concatenation-Assignment
-=	Difference-Assignment
*=	Product-Assignment
/=	Division-Assignment
%=	Modulo-Assignment
^=	Exponentiation-Assignment
&&=	Logical-And-Assignment
\|\|=	Logical-Or-Assignment

Value Types

Value type	Example
String	`"abc"`, `""`, `"a\"b\\c"`
Boolean	`true`, `false`
Int	`3`, `-9`, `0`, `135412`, `0xfe02`, `-0x1e`
Float	`3.`, `.35`, `1.00`, `0.5`, `123.554`, `23e4`, `-2e-3`, `3.54e+2`
Tuple	`(3, 55.0, false, ())`, `(1, 2)`
Empty	`()`

Common Functions

Identifier	Argument Amount	Argument Types	Description
min	>= 1	Numeric	Returns the minimum of the arguments
max	>= 1	Numeric	Returns the maximum of the arguments
len	1	String/Tuple	Returns the character length of a string, or the amount of elements in a tuple (not recursively)
floor	1	Numeric	Returns the largest integer less than or equal to a number
round	1	Numeric	Returns the nearest integer to a number. Rounds half-way cases away from 0.0
ceil	1	Numeric	Returns the smallest integer greater than or equal to a number
if	3	Boolean, Any, Any	If the first argument is true, returns the second argument, otherwise, returns the third
contains	2	Tuple, any non-tuple	Returns true if second argument exists in first tuple argument.
contains_any	2	Tuple, Tuple of any non-tuple	Returns true if one of the values in the second tuple argument exists in first tuple argument.
typeof	1	Any	returns "string", "float", "int", "boolean", "tuple", or "empty" depending on the type of the argument

String Functions

Identifier	Argument Amount	Argument Types	Description
str::regex_matches	2	String, String	Returns true if the first argument matches the regex in the second argument (Requires regex_support feature flag)
str::regex_replace	3	String, String, String	Returns the first argument with all matches of the regex in the second argument replaced by the third argument (Requires regex_supportfeature flag)
str::to_lowercase	1	String	Returns the lower-case version of the string
str::to_uppercase	1	String	Returns the upper-case version of the string
str::trim	1	String	Strips whitespace from the start and the end of the string
str::from	>= 0	Any	Returns passed value as string
str::substring	3	String, Int, Int	Returns a substring of the first argument, starting at the second argument and ending at the third argument. If the last argument is omitted, the substring extends to the end of the string

Mathematical Functions: Common

Identifier	Argument Amount	Argument Types	Description
math::abs	1	Numeric	Returns the absolute value of a number, returning an integer if the argument was an integer, and a float otherwise
math::is_nan	1	Numeric	Returns true if the argument is the floating-point value NaN, false if it is another floating-point value, and throws an error if it is not a number
math::is_finite	1	Numeric	Returns true if the argument is a finite floating-point number, false otherwise
math::is_infinite	1	Numeric	Returns true if the argument is an infinite floating-point number, false otherwise
math::is_normal	1	Numeric	Returns true if the argument is a floating-point number that is neither zero, infinite, subnormal, or NaN, false otherwise

Mathematical Functions: Logarithms and Exponents

Identifier	Argument Amount	Argument Types	Description
math::ln	1	Numeric	Returns the natural logarithm of the number
math::log	2	Numeric, Numeric	Returns the logarithm of the number with respect to an arbitrary base
math::log2	1	Numeric	Returns the base 2 logarithm of the number
math::log10	1	Numeric	Returns the base 10 logarithm of the number
math::exp	1	Numeric	Returns e^(number), (the exponential function)
math::exp2	1	Numeric	Returns 2^(number)
math::pow	2	Numeric, Numeric	Raises a number to the power of the other number
math::sqrt	1	Numeric	Returns the square root of a number. Returns NaN for a negative number
math::cbrt	1	Numeric	Returns the cube root of a number

Mathematical Functions: Trigonometry

Identifier	Argument Amount	Argument Types	Description
math::cos	1	Numeric	Computes the cosine of a number (in radians)
math::acos	1	Numeric	Computes the arccosine of a number. The return value is in radians in the range [0, pi] or NaN if the number is outside the range [-1, 1]
math::cosh	1	Numeric	Hyperbolic cosine function
math::acosh	1	Numeric	Inverse hyperbolic cosine function
math::sin	1	Numeric	Computes the sine of a number (in radians)
math::asin	1	Numeric	Computes the arcsine of a number. The return value is in radians in the range [-pi/2, pi/2] or NaN if the number is outside the range [-1, 1]
math::sinh	1	Numeric	Hyperbolic sine function
math::asinh	1	Numeric	Inverse hyperbolic sine function
math::tan	1	Numeric	Computes the tangent of a number (in radians)
math::atan	1	Numeric	Computes the arctangent of a number. The return value is in radians in the range [-pi/2, pi/2]
math::atan2	2	Numeric, Numeric	Computes the four quadrant arctangent in radians
math::tanh	1	Numeric	Hyperbolic tangent function
math::atanh	1	Numeric	Inverse hyperbolic tangent function.
math::hypot	2	Numeric	Calculates the length of the hypotenuse of a right-angle triangle given legs of length given by the two arguments