Syntax Reference

This is a compact syntax map for reading and authoring Pkl. It is not a full grammar listing; use the official language reference when exact grammar details matter.

Module Forms

module app.configamends "base.pkl"extends "template.pkl"import "db.pkl" as db

Common module forms:

• module declarations

• amends and extends

• import declarations with aliases

• top-level properties

• module-level local bindings

• class declarations

• function declarations

• typealias declarations

Literals and Values

name = "api"count = 3enabled = truemissing = null

Common string escapes include \n, \t, \r, \", and \\.

Expressions

Common expression families include:

• identifiers and member access

• safe member access

• subscript access

• arithmetic and comparison operators

• boolean operators

• null coalescing

• is and as type operands

• if (...) ... else ...

• object literals

• typed object literals

• listings and mappings

• calls and lambdas

• import("...")

• non-null assertions

• object amendments

Object Bodies

server {  host = "localhost"  port = 8080}

Object bodies are the center of Pkl authoring. Use Object Model for amendments, late binding, and receiver keywords.

Callable Syntax

function add(x: Int, y: Int): Int = x + yinc = (x: Int): Int -> x + 1

Move anonymous functions into named declarations once the logic becomes shared.

Type Syntax

name: String = "api"maybeName: String? = nullports: Listing<Int> = new Listing { 8080 }value: String | Int = "api"

Type annotations make object contracts visible to readers, editor tools, and host-language integrations.