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Object System

The object system is the core data structure mechanism of the Alia language, supporting flexible data organization and manipulation.

1. Defining Objects​

Basic syntax​

*[ <Key key>: <Value value>, ... ]  ~ object definition
*[ static <Key key>: <Value value>, ... ]  ~ static member definition
[ <Value value>, ... ]  ~ array definition

Examples​

~ Define an object
const person = *[ name: 'Alice', age: 30 ]

~ Define an array
const numbers = [1, 2, 3, 4, 5]

~ Access object properties
print person.name
print person['age']
print numbers[0]

2. Built-in Object Types​

TypeDescription
Object StringString
Object NumberNumber
Object BooleanBoolean
Object ArrayArray
Object ObjectObject
Object StackStack
Object AliasKeyword alias
Object ErrorError

3. Object Operations​

Property access​

const obj = *[ name: 'Alia', version: 0.1 ]

~ Access a property
print obj.name        ~ prints 'Alia'
print obj['version']  ~ prints 0.1

~ Set a property
obj.name = 'Alia'
obj.version = 1.0

Array operations​

const arr: [Number, ...] = [1, 2, 3]

~ Access an element
print arr[0]  ~ prints 1

~ Modify an element
arr[0] = 10

~ Array length
print arr.length  ~ prints 3

4. static Members and self​

static members​

The static keyword declares an object's static members and static methods. Static members are stored separately from regular members, do not inherit self, and can be accessed directly through the object without instantiation.

const counter = *[
  static count: 0
  static increment: alias -> {
    counter.count = counter.count + 1
    counter.count
  }
  name: 'counter'
]

print counter.count              ~ prints 0
print (call counter.increment)   ~ prints 1
print (call counter.increment)   ~ prints 2
print counter.name               ~ prints 'counter'

The self keyword​

Inside an object method, self refers to the object itself and can be used to access other members and methods within the object body. self cannot access static members; static methods can neither be accessed with self nor access self.

const obj = *[
  value: 42
  getValue: alias -> {
    self.value
  }
]

print (call obj.getValue)  ~ prints 42
const obj = *[
  static staticValue: 100
  value: 200
  tryAccessStatic: alias -> {
    self.staticValue  ~ self cannot access static members; the result is undefined
  }
]

print (call obj.tryAccessStatic)  ~ prints undefined

5. Object Static Methods​

The Object type provides a set of static methods. Multi-argument calls use auxiliary keywords to separate arguments:

const obj = *[ a: 1, b: 2 ]

print Object.keys obj                 ~ prints a,b
print Object.values obj               ~ prints 1,2
print Object.has obj keyed 'a'        ~ prints true
print Object.get obj keyed 'a'        ~ prints 1
print Object.get obj keyed 'c' or 42  ~ prints 42
Object.set obj keyed 'c' to 3
print Object.get obj keyed 'c'        ~ prints 3
print Object.delete obj keyed 'c'     ~ prints true
print Object.isObject obj             ~ prints true
MethodParametersDescription
Object.createvalueCreates an object
Object.fromEntriesentriesCreates an object from an array of key-value pairs
Object.assigntarget with source...Merges objects
Object.keysobjGets the object's array of keys
Object.valuesobjGets the object's array of values
Object.entriesobjGets the object's array of key-value pairs
Object.contactleft with rightConcatenates two objects
Object.isObjectvalueChecks whether the value is an object
Object.cloneobjClones an object
Object.hasobj keyed keyChecks whether the object contains the specified key
Object.setobj keyed key to valueSets an object property
Object.getobj keyed key or fallbackGets an object property, with a default value
Object.deleteobj keyed keyDeletes an object property
const left = *[ x: 1 ]
const right = *[ y: 2 ]

const merged = Object.contact left with right
print merged.x .. merged.y  ~ prints 12

const assigned = Object.assign left with right
print assigned.y            ~ prints 2

6. Example Code​

~ Comprehensive object system example

~ 1. Create an object
const car = *[
  brand: 'Tesla',
  model: 'Model 3',
  year: 2023,
  features: ['autopilot', 'touchscreen', 'electric']
]

~ 2. Access object properties
print 'Brand: ' .. car.brand
print 'Model: ' .. car.model
print 'Year: ' .. car.year

~ 3. Iterate over an array
print 'Features:'
for { let i = 0 } i < car.features.length { i ++ } {
  print '  - ' .. car.features[i]
}

~ 4. Modify a property
car.year = 2024
print 'Updated year: ' .. car.year

~ 5. Add a new property
Object.set car keyed 'color' to 'white'
print 'Color: ' .. car.color

~ 6. Create a complex object
const company = *[
  name: 'Tech Corp',
  employees: [
    *[ name: 'Alice', role: 'Engineer' ],
    *[ name: 'Bob', role: 'Manager' ]
  ],
  departments: *[
    engineering: 50,
    marketing: 20,
    sales: 30
  ]
]

~ 7. Access nested properties
print 'Company: ' .. company.name
print 'Engineers: ' .. company.departments.engineering
print 'First employee: ' .. company.employees[0].name

Next Steps​