ExpressionBuilder

open class ExpressionBuilder(operator: String) : Expression.Builder

Builder for Expression.

Parameters

operator

compulsory operator field for the builder

Constructors

ExpressionBuilder
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fun ExpressionBuilder(operator: String)

Functions

abs
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fun abs(value: Double)
fun abs(block: Expression.ExpressionBuilder.() -> Unit)

Returns the absolute value of the input.

accumulated
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fun accumulated()

Returns the value of a cluster property accumulated so far. Can only be used in the clusterProperties option of a clustered GeoJSON source.

acos
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fun acos(value: Double)
fun acos(block: Expression.ExpressionBuilder.() -> Unit)

Returns the arccosine of the input.

addArgument
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fun addArgument(expression: Expression): Expression.ExpressionBuilder

Add an Expression to the builder.

all
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fun all(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if all the inputs are true, false otherwise. The inputs are evaluated in order, and evaluation is short-circuiting: once an input expression evaluates to false, the result is false and no further input expressions are evaluated.

any
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fun any(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if any of the inputs are true, false otherwise. The inputs are evaluated in order, and evaluation is short-circuiting: once an input expression evaluates to true, the result is true and no further input expressions are evaluated.

array
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fun array(block: Expression.ExpressionBuilder.() -> Unit)

Asserts that the input is an array (optionally with a specific item type and length). If, when the input expression is evaluated, it is not of the asserted type, then this assertion will cause the whole expression to be aborted.

asin
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fun asin(value: Double)
fun asin(block: Expression.ExpressionBuilder.() -> Unit)

Returns the arcsine of the input.

at
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fun at(block: Expression.ExpressionBuilder.() -> Unit)
fun at(index: Double, array: Expression)

Retrieves an item from an array.

atan
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fun atan(value: Double)
fun atan(block: Expression.ExpressionBuilder.() -> Unit)

Returns the arctangent of the input.

boolean
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fun boolean(block: Expression.ExpressionBuilder.() -> Unit)

Asserts that the input value is a boolean. If multiple values are provided, each one is evaluated in order until a boolean is obtained. If none of the inputs are booleans, the expression is an error.

build
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open fun build(): Expression

Build the Expression with the settings.

ceil
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fun ceil(value: Double)
fun ceil(block: Expression.ExpressionBuilder.() -> Unit)

Returns the smallest integer that is greater than or equal to the input.

coalesce
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fun coalesce(block: Expression.ExpressionBuilder.() -> Unit)

Evaluates each expression in turn until the first valid value is obtained. Invalid values are null and #types-image expressions that are unavailable in the style. If all values are invalid, coalesce returns the first value listed.

collator
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fun collator(block: Expression.CollatorBuilder.() -> Unit)

Returns a collator for use in locale-dependent comparison operations. The case-sensitive and diacritic-sensitive options default to false. The locale argument specifies the IETF language tag of the locale to use. If none is provided, the default locale is used. If the requested locale is not available, the collator will use a system-defined fallback locale. Use resolved-locale to test the results of locale fallback behavior.

color
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fun color(@ColorInt intColor: Int)

Add a color expression to the current expression builder.

concat
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fun concat(vararg values: String)

Returns a string consisting of the concatenation of the inputs.

fun concat(block: Expression.ExpressionBuilder.() -> Unit)

Returns a string consisting of the concatenation of the inputs. Each input is converted to a string as if by to-string.

cos
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fun cos(value: Double)
fun cos(block: Expression.ExpressionBuilder.() -> Unit)

Returns the cosine of the input.

distance
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fun distance(geojson: GeoJson)

Returns the shortest distance in meters between the evaluated feature and the input geometry. The input value can be a valid GeoJSON of type Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, Feature, or FeatureCollection. Distance values returned may vary in precision due to loss in precision from encoding geometries, particularly below zoom level 13.

distanceFromCenter
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fun distanceFromCenter()

Returns the distance of a symbol instance from the center of the map. The distance is measured in pixels divided by the height of the map container. It measures 0 at the center, decreases towards the camera and increase away from the camera. For example, if the height of the map is 1000px, a value of -1 means 1000px away from the center towards the camera, and a value of 1 means a distance of 1000px away from the camera from the center. ["distance-from-center"] may only be used in the filter expression for a symbol layer.

division
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fun division(block: Expression.ExpressionBuilder.() -> Unit)
fun division(first: Double, second: Double)

Returns the result of floating point division of the first input by the second.

downcase
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fun downcase(block: Expression.ExpressionBuilder.() -> Unit)
fun downcase(value: String)

Returns the input string converted to lowercase. Follows the Unicode Default Case Conversion algorithm and the locale-insensitive case mappings in the Unicode Character Database.

e
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fun e()

Returns the mathematical constant e.

eq
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fun eq(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if the input values are equal, false otherwise. The comparison is strictly typed: values of different runtime types are always considered unequal. Cases where the types are known to be different at parse time are considered invalid and will produce a parse error. Accepts an optional collator argument to control locale-dependent string comparisons.

featureState
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fun featureState(block: Expression.ExpressionBuilder.() -> Unit)

Retrieves a property value from the current feature's state. Returns null if the requested property is not present on the feature's state. A feature's state is not part of the GeoJSON or vector tile data, and must be set programmatically on each feature. Features are identified by their id attribute, which must be an integer or a string that can be cast to an integer. Note that "feature-state" can only be used with paint properties that support data-driven styling.

floor
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fun floor(value: Double)
fun floor(block: Expression.ExpressionBuilder.() -> Unit)

Returns the largest integer that is less than or equal to the input.

format
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fun format(block: Expression.FormatBuilder.() -> Unit)

Returns a formatted string for displaying mixed-format text in the text-field property. The input may contain a string literal or expression, including an #types-image expression. Strings may be followed by a style override object that supports the following properties:

geometryType
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fun geometryType()

Returns the feature's geometry type: Point, LineString or Polygon. Multi- feature types return the singular forms.

get
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fun get(block: Expression.ExpressionBuilder.() -> Unit)

Retrieves a property value from the current feature's properties, or from another object if a second argument is provided. Returns null if the requested property is missing.

fun get(key: String)

Retrieves a property value from the current feature's properties. Returns null if the requested property is missing.

fun get(key: String, expression: Expression)

Retrieves a property value from the current feature's properties, or from another object if a second argument is provided. Returns null if the requested property is missing.

gt
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fun gt(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if the first input is strictly greater than the second, false otherwise. The arguments are required to be either both strings or both numbers; if during evaluation they are not, expression evaluation produces an error. Cases where this constraint is known not to hold at parse time are considered in valid and will produce a parse error. Accepts an optional collator argument to control locale-dependent string comparisons.

gte
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fun gte(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if the first input is greater than or equal to the second, false otherwise. The arguments are required to be either both strings or both numbers; if during evaluation they are not, expression evaluation produces an error. Cases where this constraint is known not to hold at parse time are considered in valid and will produce a parse error. Accepts an optional collator argument to control locale-dependent string comparisons.

has
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fun has(block: Expression.ExpressionBuilder.() -> Unit)
fun has(string: String, expression: Expression)

Tests for the presence of an property value in the current feature's properties, or from another object if a second argument is provided.

fun has(string: String)

Tests for the presence of an property value in the current feature's properties

heatmapDensity
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fun heatmapDensity()

Returns the kernel density estimation of a pixel in a heatmap layer, which is a relative measure of how many data points are crowded around a particular pixel. Can only be used in the heatmap-color property.

id
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fun id()

Returns the feature's id, if it has one.

image
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fun image(block: Expression.ExpressionBuilder.() -> Unit)

Returns a /mapbox-gl-js/style-spec/types/#resolvedimage for use in /mapbox-gl-js/style-spec/layers/#layout-symbol-icon-image, --pattern entries, and as a section in the #types-format expression. A #coalesce expression containing image expressions will evaluate to the first listed image that is currently in the style. This validation process is synchronous and requires the image to have been added to the style before requesting it in the 'image' argument.

indexOf
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fun indexOf(block: Expression.ExpressionBuilder.() -> Unit)

Returns the first position at which an item can be found in an array or a substring can be found in a string, or -1 if the input cannot be found. Accepts an optional index from where to begin the search.

inExpression
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fun inExpression(block: Expression.ExpressionBuilder.() -> Unit)

Determines whether an item exists in an array or a substring exists in a string. In the specific case when the second and third arguments are string literals, you must wrap at least one of them in a #types-literal expression to hint correct interpretation to the #type-system.

fun inExpression(needle: Double, haystack: Expression)
fun inExpression(needle: String, haystack: Expression)

Determines whether an item exists in an array or a substring exists in a string.

interpolate
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fun interpolate(block: Expression.InterpolatorBuilder.() -> Unit)

Produces continuous, smooth results by interpolating between pairs of input and output values ("stops"). The input may be any numeric expression (e.g., ["get", "population"]). Stop inputs must be numeric literals in strictly ascending order. The output type must be number, array<number>, or color.

isSupportedScript
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fun isSupportedScript(block: Expression.ExpressionBuilder.() -> Unit)
fun isSupportedScript(script: String)

Returns true if the input string is expected to render legibly. Returns false if the input string contains sections that cannot be rendered without potential loss of meaning (e.g. Indic scripts that require complex text shaping, or right-to-left scripts if the the mapbox-gl-rtl-text plugin is not in use in Mapbox GL JS).

length
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fun length(block: Expression.ExpressionBuilder.() -> Unit)

Returns the length of an array or string.

fun length(string: String)

Gets the length of an string.

letExpression
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fun letExpression(block: Expression.ExpressionBuilder.() -> Unit)

Binds expressions to named variables, which can then be referenced in the result expression using "var", "variable_name".

lineProgress
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fun lineProgress()

Returns the progress along a gradient line. Can only be used in the line-gradient property.

literal
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fun literal(value: HashMap<String, Any>)
fun literal(value: Boolean)
fun literal(value: Double)
fun literal(value: Long)
fun literal(value: String)
fun literal(value: List<Any>)

Provides a literal array or object value.

ln
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fun ln(value: Double)
fun ln(block: Expression.ExpressionBuilder.() -> Unit)

Returns the natural logarithm of the input.

ln2
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fun ln2()

Returns mathematical constant ln(2).

log10
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fun log10(value: Double)
fun log10(block: Expression.ExpressionBuilder.() -> Unit)

Returns the base-ten logarithm of the input.

log2
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fun log2(value: Double)
fun log2(block: Expression.ExpressionBuilder.() -> Unit)

Returns the base-two logarithm of the input.

lt
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fun lt(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if the first input is strictly less than the second, false otherwise. The arguments are required to be either both strings or both numbers; if during evaluation they are not, expression evaluation produces an error. Cases where this constraint is known not to hold at parse time are considered in valid and will produce a parse error. Accepts an optional collator argument to control locale-dependent string comparisons.

lte
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fun lte(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if the first input is less than or equal to the second, false otherwise. The arguments are required to be either both strings or both numbers; if during evaluation they are not, expression evaluation produces an error. Cases where this constraint is known not to hold at parse time are considered in valid and will produce a parse error. Accepts an optional collator argument to control locale-dependent string comparisons.

match
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fun match(block: Expression.ExpressionBuilder.() -> Unit)

Selects the output for which the label value matches the input value, or the fallback value if no match is found. The input can be any expression (for example, ["get", "building_type"]). Each label must be unique, and must be either:

max
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fun max(vararg values: Double)
fun max(block: Expression.ExpressionBuilder.() -> Unit)

Returns the maximum value of the inputs.

min
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fun min(vararg values: Double)
fun min(block: Expression.ExpressionBuilder.() -> Unit)

Returns the minimum value of the inputs.

mod
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fun mod(block: Expression.ExpressionBuilder.() -> Unit)
fun mod(first: Double, second: Double)

Returns the remainder after integer division of the first input by the second.

neq
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fun neq(block: Expression.ExpressionBuilder.() -> Unit)

Returns true if the input values are not equal, false otherwise. The comparison is strictly typed: values of different runtime types are always considered unequal. Cases where the types are known to be different at parse time are considered invalid and will produce a parse error. Accepts an optional collator argument to control locale-dependent string comparisons.

not
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fun not(bool: Boolean)
fun not(block: Expression.ExpressionBuilder.() -> Unit)

Logical negation. Returns true if the input is false, and false if the input is true.

number
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fun number(block: Expression.ExpressionBuilder.() -> Unit)

Asserts that the input value is a number. If multiple values are provided, each one is evaluated in order until a number is obtained. If none of the inputs are numbers, the expression is an error.

numberFormat
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fun numberFormat(input: Expression, block: Expression.NumberFormatBuilder.() -> Unit)

Converts the input number into a string representation using the providing formatting rules. If set, the locale argument specifies the locale to use, as a BCP 47 language tag. If set, the currency argument specifies an ISO 4217 code to use for currency-style formatting. If set, the unit argument specifies a simple ECMAScript unit to use for unit-style formatting. If set, the min-fraction-digits and max-fraction-digits arguments specify the minimum and maximum number of fractional digits to include.

fun numberFormat(value: Double, block: Expression.NumberFormatBuilder.() -> Unit)

Converts the input number into a string representation using the providing formatting rules. If set, the locale argument specifies the locale to use, as a BCP 47 language tag. If set, the currency argument specifies an ISO 4217 code to use for currency-style formatting. If set, the min-fraction-digits and max-fraction-digits arguments specify the minimum and maximum number of fractional digits to include.

objectExpression
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fun objectExpression(block: Expression.ExpressionBuilder.() -> Unit)

Asserts that the input value is an object. If multiple values are provided, each one is evaluated in order until an object is obtained. If none of the inputs are objects, the expression is an error.

pi
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fun pi()

Returns the mathematical constant pi.

pitch
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fun pitch()

Returns the current pitch in degrees. ["pitch"] may only be used in the filter expression for a symbol layer.

pow
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fun pow(block: Expression.ExpressionBuilder.() -> Unit)
fun pow(first: Double, second: Double)

Returns the result of raising the first input to the power specified by the second.

product
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fun product(vararg double: Double)
fun product(block: Expression.ExpressionBuilder.() -> Unit)

Returns the product of the inputs.

properties
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fun properties()

Returns the feature properties object. Note that in some cases, it may be more efficient to use ["get", "property_name"] directly.

resolvedLocale
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fun resolvedLocale(block: Expression.ExpressionBuilder.() -> Unit)

Returns the IETF language tag of the locale being used by the provided collator. This can be used to determine the default system locale, or to determine if a requested locale was successfully loaded.

rgb
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fun rgb(block: Expression.ExpressionBuilder.() -> Unit)

Creates a color value from red, green, and blue components, which must range between 0 and 255, and an alpha component of 1. If any component is out of range, the expression is an error.

fun rgb(red: Double, green: Double, blue: Double)

Add a RGB color expression from numbers to the current expression builder.

rgba
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fun rgba(block: Expression.ExpressionBuilder.() -> Unit)

Creates a color value from red, green, blue components, which must range between 0 and 255, and an alpha component which must range between 0 and 1. If any component is out of range, the expression is an error.

fun rgba(red: Double, green: Double, blue: Double, alpha: Double)

Add a RGBA color expression from numbers to the current expression builder.

round
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fun round(value: Double)
fun round(block: Expression.ExpressionBuilder.() -> Unit)

Rounds the input to the nearest integer. Halfway values are rounded away from zero. For example, ["round", -1.5] evaluates to -2.

sin
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fun sin(value: Double)
fun sin(block: Expression.ExpressionBuilder.() -> Unit)

Returns the sine of the input.

skyRadialProgress
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fun skyRadialProgress()

Returns the distance of a point on the sky from the sun position. Returns 0 at sun position and 1 when the distance reaches sky-gradient-radius. Can only be used in the sky-gradient property.

slice
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fun slice(block: Expression.ExpressionBuilder.() -> Unit)

Returns an item from an array or a substring from a string from a specified start index, or between a start index and an end index if set. The return value is inclusive of the start index but not of the end index.

sqrt
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fun sqrt(value: Double)
fun sqrt(block: Expression.ExpressionBuilder.() -> Unit)

Returns the square root of the input.

step
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fun step(block: Expression.ExpressionBuilder.() -> Unit)

Produces discrete, stepped results by evaluating a piecewise-constant function defined by pairs of input and output values ("stops"). The input may be any numeric expression (e.g., ["get", "population"]). Stop inputs must be numeric literals in strictly ascending order. Returns the output value of the stop just less than the input, or the first output if the input is less than the first stop.

stop
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fun stop(block: Expression.ExpressionBuilder.() -> Unit)
fun stop(key: Double, block: Expression.ExpressionBuilder.() -> Unit)

Add a pair of input and output values. The input may be any numeric expression (e.g., ["get", "population"]). Stop inputs must be numeric literals in strictly ascending order. Returns the output value of the stop just less than the input, or the first output if the input is less than the first stop.

string
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fun string(block: Expression.ExpressionBuilder.() -> Unit)

Asserts that the input value is a string. If multiple values are provided, each one is evaluated in order until a string is obtained. If none of the inputs are strings, the expression is an error.

subtract
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fun subtract(value: Double)

Returns the result of subtracting it from 0.

fun subtract(block: Expression.ExpressionBuilder.() -> Unit)

For two inputs, returns the result of subtracting the second input from the first. For a single input, returns the result of subtracting it from 0.

fun subtract(first: Double, second: Double)

Returns the result of subtracting the second input from the first.

sum
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fun sum(vararg double: Double)
fun sum(block: Expression.ExpressionBuilder.() -> Unit)

Returns the sum of the inputs.

switchCase
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fun switchCase(block: Expression.ExpressionBuilder.() -> Unit)

Selects the first output whose corresponding test condition evaluates to true, or the fallback value otherwise.

tan
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fun tan(value: Double)
fun tan(block: Expression.ExpressionBuilder.() -> Unit)

Returns the tangent of the input.

toBoolean
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fun toBoolean(block: Expression.ExpressionBuilder.() -> Unit)

Converts the input value to a boolean. The result is false when then input is an empty string, 0, false, null, or NaN; otherwise it is true.

toColor
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fun toColor(block: Expression.ExpressionBuilder.() -> Unit)

Converts the input value to a color. If multiple values are provided, each one is evaluated in order until the first successful conversion is obtained. If none of the inputs can be converted, the expression is an error.

toNumber
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fun toNumber(block: Expression.ExpressionBuilder.() -> Unit)

Converts the input value to a number, if possible. If the input is null or false, the result is 0. If the input is true, the result is 1. If the input is a string, it is converted to a number as specified by the "ToNumber Applied to * the String Type" algorithm of the ECMAScript Language Specification. If multiple values are provided, each one is evaluated in order until the first successful conversion is obtained. If none of the inputs can be converted, the expression is an error.

toRgba
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fun toRgba(block: Expression.ExpressionBuilder.() -> Unit)

Returns a four-element array containing the input color's red, green, blue, and alpha components, in that order.

toString
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fun toString(block: Expression.ExpressionBuilder.() -> Unit)

Converts the input value to a string. If the input is null, the result is "". If the input is a #types-boolean, the result is "true" or "false". If the input is a number, it is converted to a string as specified by the "NumberToString" algorithm of the ECMAScript Language Specification. If the input is a #color, it is converted to a string of the form "rgba(r,g,b,a)", where r, g, and b are numerals ranging from 0 to 255, and a ranges from 0 to 1. If the input is an #types-image expression, 'to-string' returns the image name. Otherwise, the input is converted to a string in the format specified by the JSON.stringify function of the ECMAScript Language Specification.

typeofExpression
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fun typeofExpression(block: Expression.ExpressionBuilder.() -> Unit)

Returns a string describing the type of the given value.

upcase
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fun upcase(block: Expression.ExpressionBuilder.() -> Unit)
fun upcase(value: String)

Returns the input string converted to uppercase. Follows the Unicode Default Case Conversion algorithm and the locale-insensitive case mappings in the Unicode Character Database.

varExpression
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fun varExpression(block: Expression.ExpressionBuilder.() -> Unit)
fun varExpression(value: String)

References variable bound using "let".

within
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fun within(geometry: Geometry)

Returns true if the evaluated feature is fully contained inside a boundary of the input geometry, false otherwise. The input value can be a valid GeoJSON of type Polygon, MultiPolygon, Feature, or FeatureCollection. Supported features for evaluation:

zoom
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fun zoom()

Returns the current zoom level. Note that in style layout and paint properties, "zoom" may only appear as the input to a top-level "step" or "interpolate" expression.

Inheritors

Expression
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