Packages > pkl > pkl.syntax

Node0.33.0

Overview
Properties
Methods

class Node

A generic, untyped node in the Pkl syntax tree.

Known subtypes in package:
Known usages in package:
All versions:

Properties

link

type: NodeType

The kind of this node.
link

children: List<Node>(isTerminal.implies(isEmpty))

The child nodes, in source order. Empty for leaf nodes.
link

hidden

parent: Node?

The parent node, or null for the root and for nodes not attached to a tree.
link

text: String?(isTerminal.implies(this != null))

The verbatim source text for this node.

FormattingRenderer only renders this text if this is a terminal node.
link

span: Span?

The source location of this node.
link

isTerminal: Boolean

Tells if this is a terminal node; i.e. a node that spans a single token of the grammar.

A terminal never has children, but not every node without children is a terminal.

Methods(show inherited)

link

function

Any.getClass(): Class<this> (pkl.base)Source

Returns the class of this.
link

function

Any.toString(): String (pkl.base)Source

Returns a string representation of this.

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

function

Any.ifNonNull<Result>(transform: (this) -> Result): Result? (pkl.base)Source

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.
link

function

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

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

function

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

Returns the value of the property with the given name.

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

function

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

Returns the value of the property with the given name.

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

function

Typed.toDynamic(): Dynamic (pkl.base)Source

Converts this object to a Dynamic object.
link

function

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

Converts this object to a Map.
link

function
fold<Result>(initial: Result, operator: (Result, Node) -> Result): Result

Fold operator over this node and its descendants, top-down in pre-order.
Example:
```
// count the if-expressions in a module
module.fold(0, (acc, n) -> if (n.type == "if_expr") acc + 1 else acc)
```
link

function
findChild(predicate: (Node) -> Boolean): Node

Returns the first child matching predicate, searching depth-first in pre-order.
Child means any node below this one, at any depth. This node itself is not considered. The search stops at the first match.

Throws if no child matches predicate.

Example:
```
// the name of the first class declared in a module
module.findChild((n) -> n.type == "class").findChildOfType("identifier").text
```
link

function

findChildOrNull(predicate: (Node) -> Boolean): Node?

Same as findChild() but returns null if no child matches predicate.
link

function

findChildren(predicate: (Node) -> Boolean): List<Node>

Returns every child matching predicate, in depth-first pre-order.

Child means any node below this one, at any depth. This node itself is not considered. A matching node is searched for further matches, so a match may contain another.
link

function

findChildOfType(type: NodeType): Node

Returns the first child whose type is type.

Throws if no child has this type.
link

function

findChildOfTypeOrNull(type: NodeType): Node?

Same as findChildOfType() but returns null if no child has this type.
link

function

findChildrenOfType(type: NodeType): List<Node>

Returns every child whose type is type, in depth-first pre-order.
link

function

replaceChild(predicate: (Node) -> Boolean, replacer: (Node) -> Node): Node

Returns this node with the first child matching predicate replaced by replacer's result.

The child replaced is the one findChild() returns. If there is none, the tree is returned unchanged. The replacement is left as it is, so it is not searched for further matches.
link

function

replaceChildren(predicate: (Node) -> Boolean, replacer: (Node) -> Node): Node

Returns this node with every child matching predicate replaced by replacer's result.

The children replaced are those findChildren() returns, except that a replacement is left as it is, so a match nested in another match is left to replacer.
link

function

replaceChildOfType(type: NodeType, replacer: (Node) -> Node): Node

Returns this node with the first child whose type is type replaced by replacer's result.

If there is no such child, the tree is returned unchanged.
link

function

replaceChildrenOfType(type: NodeType, replacer: (Node) -> Node): Node

Returns this node with every child whose type is type replaced by replacer's result.
link

function

findParent(predicate: (Node) -> Boolean): Node

Returns the nearest parent matching predicate.

Throws if no parent matches predicate.
link

function

findParentOrNull(predicate: (Node) -> Boolean): Node?

Same as findParent() but returns null if no parent matches predicate.
link

function

findParentOfType(type: NodeType): Node

Returns the nearest parent whose type is type.

Throws if no parent has this type.
link

function

findParentOfTypeOrNull(type: NodeType): Node?

Same as findParentOfType() but returns null if no parent has this type.
link

function

findParents(predicate: (Node) -> Boolean): List<Node>

Returns every parent matching predicate, nearest first.
link

function

hasParent(predicate: (Node) -> Boolean): Boolean

Tells whether any parent matches predicate.
link

function

hasParentOfType(type: NodeType): Boolean

Tells whether any parent's type is type.