Packages > pkl

pkl.base0.27.1

Overview
Properties
Methods
Classes
Type Aliases

module pkl.base

Fundamental properties, methods, and classes for writing Pkl programs.

Module URI:: pkl:base
Pkl version:: 0.27.0 or higher
Known subtypes:
Known usages:
All versions:

Properties(show inherited)

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hidden

output: ModuleOutput (pkl.base)

The output of this module.

Defaults to all module properties rendered as either Pcf or the format specified on the command line.
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NaN: Float

The Float value that is not a number (NaN).
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Infinity: Float

The Float value that is positive Infinity. For negative infinity, use -Infinity.

Methods(show inherited)

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function

getClass(): Class (pkl.base)

Returns the class of this.
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function

toString(): String (pkl.base)

Returns a string representation of this.

This method is used to convert the values of string interpolation expressions to strings.
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function

ifNonNull<Result>(transform: (NonNull) -> Result): Result? (pkl.base)

Returns this |> transform if this is non-null, and null otherwise.

This method is the complement of the ?? operator and the equivalent of an Option type's map and flatMap methods.
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function

hasProperty(name: String): Boolean (pkl.base)

Tells if this object has a property with the given name.
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function

getProperty(name: String): unknown (pkl.base)

Returns the value of the property with the given name.

Throws if a property with this name does not exist.
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function

getPropertyOrNull(name: String): unknown? (pkl.base)

Returns the value of the property with the given name.

Returns null if a property with this name does not exist.
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function

toDynamic(): Dynamic (pkl.base)

Converts this object to a Dynamic object.
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function

toMap(): Map<String, unknown> (pkl.base)

Converts this object to a Map.
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function
relativePathTo(other: Module): List<String> (pkl.base)

Returns the relative, descendent directory path between this module and other.
Throws if no such path exists.

For example, if module mod1 has path /dir1/mod1.pkl, and module mod2 has path /dir1/dir2/dir3/mod2.pkl, then mod1.relativePathTo(mod2) will return List("dir2", "dir3").

A common use case is to compute the directory path between a template located at the root of a hierarchy (say rootModule.pkl) and the currently evaluated module (accessible via the module keyword):
```
import "rootModule.pkl" // self-import
path = rootModule.relativePathTo(module)
```
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function

Regex(pattern: String): Regex

Constructs a regular expression described by pattern.

Throws if pattern is not a valid regular expression.

To test if pattern is a valid regular expression, use String.isRegex.
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function

Undefined(): nothing

Throws an error indicating that the requested value is undefined.
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function

TODO(): nothing

Throws an error indicating that the requested functionality has not yet been implemented.
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function

Null(defaultValue: Object|Function<Object>): Null

Creates a null value that turns into defaultValue when amended.
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function

Pair<First, Second>(first: First, second: Second): Pair<First, Second>

Constructs a Pair.
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function

IntSeq(start: Int, end: Int): IntSeq

Constructs an IntSeq with the given start, end, and step 1.

To set a step other than 1, use method IntSeq.step().
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function
List<Element>(elements: VarArgs<Element>): List<Element>

Creates a list containing the given elements.
This method accepts any number of arguments.

Facts:
```
List().isEmpty
List("one", "two", "three").contains("two")
```
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function
Set<Element>(elements: VarArgs<Element>): Set<Element>

Creates a set containing the given elements.
This method accepts any number of arguments.

Facts:
```
Set().isEmpty
Set("one", "two", "three").contains("two")
```
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function
Map<Key, Value>(keysAndValues: VarArgs<(Key|Value)>): Map<Key, Value>

Creates a map containing the given alternating keysAndValues.
This method accepts any even number of arguments. Facts:
```
Map().isEmpty
Map("name", "Pigeon", "age", 42).keys == Set("name", "age")
Map("name", "Pigeon", "age", 42).values == Set("Pigeon", 42)
```

Classes

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abstract external class

Any

The top type of the type hierarchy.
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external class

Null extends Any

The type of null and null values created with Null().
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external class

Class<out Type> extends Any

The runtime representation of a class.
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external class

TypeAlias extends Any

The runtime representation of a type alias.
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abstract external class

Module

Base class for modules.
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abstract class

Annotation

Base class for annotation types.
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class

Since extends Annotation

Indicates that the annotated member was introduced in version.
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class

Deprecated extends Annotation

Indicates that the annotated member is deprecated and will likely be removed in the future.
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class

AlsoKnownAs extends Annotation

Lists alternative names that the annotated member is known under.
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class

Unlisted extends Annotation

Indicates that the annotated member should not be advertised by Pkldoc and other tools.
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class

DocExample extends Annotation

Indicates to Pkldoc that the annotated module is an example for how to use subjects.
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class

SourceCode extends Annotation

Indicates that the annotated property's string value contains source code written in language.
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class

ModuleInfo extends Annotation

Metadata for a module.
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open class

FileOutput

A representation of a rendered output.
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class

ModuleOutput extends FileOutput

The contents and appearance of a module's output.
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abstract class

ValueRenderer

Base class for rendering Pkl values in some output format.
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class

PcfRenderer extends ValueRenderer

Renders values as Pcf, a static subset of Pkl.
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class

RenderDirective

Directs a ValueRenderer to output text as-is in place of this directive.
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class

PcfRenderDirective

Directs PcfRenderer to output additional text before and/or after rendering a value.
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class

JsonRenderer extends ValueRenderer

Renders values as JSON.
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class

YamlRenderer extends ValueRenderer

Renders values as YAML.
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class

PListRenderer extends ValueRenderer

Renders values as XML property lists.
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class

PropertiesRenderer extends ValueRenderer

Renders values as Java Properties.
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class

Resource

An external (file, HTTP, etc.) resource.
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abstract external class

Number extends Any

Common base class of Int and Float.
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external class

Int extends Number

A 64-bit signed integer.
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external class

Float extends Number

A 64-bit floating-point number conforming to the IEEE 754 binary64 format.
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external class

Boolean extends Any

A boolean value, either true or false.
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external class

String extends Any

A sequence of Unicode characters (code points).
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external class

Regex

A regular expression to match strings against.
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class

RegexMatch

A match of a regular expression in a string.
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external class

Duration extends Any

A quantity of elapsed time, represented as a value (e.g. 30.5) and unit (e.g. min).
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external class

DataSize extends Any

A quantity of binary data, represented as a value (e.g. 30.5) and unit (e.g. mb).
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abstract external class

Object extends Any

A composite value containing members (properties, elements, entries).
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abstract class

Typed extends Object

Base class for objects whose members are described by a class definition.
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class

Dynamic extends Object

An object that can contain arbitrary properties, elements, and entries.
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class

Listing<out Element> extends Object

An object containing an ordered sequence of elements.
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class

Mapping<out Key, out Value> extends Object

An object containing an ordered sequence of key-value pairs.
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abstract external class

Function<out Result> extends Any

Base class for function literals (also known as lambda expressions).
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external class

Function0<out Result> extends Function<Result>

A function literal with zero parameters.
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external class

Function1<in Param1, out Result> extends Function<Result>

A function literal with one parameter.
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external class

Function2<in Param1, in Param2, out Result> extends Function<Result>

A function literal with two parameters.
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external class

Function3<in Param1, in Param2, in Param3, out Result> extends Function<Result>

A function literal with three parameters.
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external class

Function4<in Param1, in Param2, in Param3, in Param4, out Result> extends Function<Result>

A function literal with four parameters.
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external class

Function5<in Param1, in Param2, in Param3, in Param4, in Param5, out Result> extends Function<Result>

A function literal with five parameters.
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external class

Pair<out First, out Second> extends Any

An ordered pair of elements.
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abstract external class

Collection<out Element> extends Any

Common base class for List and Set.
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external class

IntSeq extends Any

A finite arithmetic sequence of integers.
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external class

VarArgs<Type>

A variable number of method arguments of type Type.
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external class

List<out Element> extends Collection<Element>

An indexed sequence of elements.
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external class

Set<out Element> extends Collection<Element>

An unordered collection of unique elements.
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external class

Map<out Key, out Value> extends Any

An unordered mapping from keys to values.

Type Aliases

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typealias

NonNull = Any(!(this is Null))

A non-null value.
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typealias

Int8 = Int(isBetween(-128, 127))

An Int value in range math.minInt8..math.maxInt8.
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typealias

Int16 = Int(isBetween(-32768, 32767))

An Int value in range math.minInt16..math.maxInt16.
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typealias

Int32 = Int(isBetween(-2147483648, 2147483647))

An Int value in range math.minInt32..math.maxInt32.
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typealias

UInt8 = Int(isBetween(0, 255))

An Int value in range 0..math.maxUInt8.
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typealias

UInt16 = Int(isBetween(0, 65535))

An Int value in range 0..math.maxUInt16.
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typealias

UInt32 = Int(isBetween(0, 4294967295))

An Int value in range 0..math.maxUInt32.
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typealias

UInt = Int(isPositive)

An Int value in range 0..math.maxUInt.

Note that math.maxUInt is equal to math.maxInt, not maxInt * 2 + 1 as one might expect. That is, UInt has half the range of Int.
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typealias

Comparable = String|Number|Duration|DataSize

A value that can be compared to another value of the same type with <, >, <=, and >=.
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typealias

Char = String(length == 1)

A Unicode character (code point).
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typealias

Uri = String

A string representing a URI.
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typealias

DurationUnit = "ns"|"us"|"ms"|"s"|"min"|"h"|"d"

The unit of a Duration.
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typealias

DataSizeUnit = "b"|"kb"|"kib"|"mb"|"mib"|"gb"|"gib"|"tb"|"tib"|"pb"|"pib"

The unit of a DataSize.
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typealias
Mixin<Type> = (Type) -> Type

An anonymous function used to apply the same modification to different objects.
Even though mixins are regular Functions, they are best created with object syntax:
```
withNamePigeon = new Mixin<Person> { name = "Pigeon" }  // explicit type
withNamePigeon: Mixin<Person> = new { name = "Pigeon" } // inferred type
```
To apply a mixin to an object, use the |> (pipe) operator:
```
pigeon = person |> withNamePigeon
```
Like all object-returning functions, mixins can be amended:
```
withNamePigeonAndAge42 = (withNamePigeon) { age = 42 }
pigeon42 = person |> withNamePigeonAndAge42
```