Starlight Language Guide

Welcome to Starlight Language, a simple and expressive server-side scripting programming language designed for clarity and flexibility.

This guide introduces the core concepts and syntax to help you start writing programs quickly.

1. Hello World

sldeploy "Hello, world!"

2. Variables

Variables are declared using the define keyword.

define name = "Alice"
define age = 20

Supported Value Types

| Type | Example | | ------- | -------------------- | | Number | 10, 3.14 | | String | "hello" | | Boolean | true, false | | Array | [1, 2, 3] | | Object | { "a": 1, "b": 2 } | | Null | null |

3. Output

Use sldeploy to print values:

sldeploy name
sldeploy age

4. Input

Use ask to read user input:

define name = ask("Enter your name:")
sldeploy "Hello " + name

5. Operators

Arithmetic Operators

| Operator | Description | | -------- | -------------- | | + | Addition | | - | Subtraction | | * | Multiplication | | / | Division | | % | Modulus |

Example:

define result = 10 + 5 * 2

Comparison Operators

| Operator | Description | | -------- | --------------------- | | == | Equal | | != | Not equal | | < | Less than | | <= | Less than or equal | | > | Greater than | | >= | Greater than or equal |

Logical Operators

| Operator | Description | | -------- | --------------- | | AND | Logical AND | | OR | Logical OR | | ?? | Null coalescing |

Example:

define x = null ?? 10

6. Conditional Statements

if (age > 18) {
    sldeploy "Adult"
} else {
    sldeploy "Minor"
}

7. Loops

While Loop

define i = 0

while (i < 5) {
    sldeploy i
    i = i + 1
}

For Loop

for (define i = 0; i < 5; i = i + 1) {
    sldeploy i
}

For-In Loop

define arr = [10, 20, 30]

for x in arr {
    sldeploy x
}

8. Functions

Function Declaration

func add(a, b) {
    return a + b
}

Function Usage

define result = add(2, 3)
sldeploy result

Arrow Functions

define add = (a, b) => a + b

9. Arrays

define arr = [1, 2, 3]

sldeploy arr[0]

Common Array Operations

| Function | Description | | -------- | ------------------- | | push | Add element | | pop | Remove last element |

push(arr, 4)
pop(arr)

10. Objects

define user = {
    "name": "Alice",
    "age": 20
}

sldeploy user.name

11. Slicing

define arr = [1, 2, 3, 4, 5]

sldeploy arr[1:4]
sldeploy arr[0:5:2]

Slice Syntax

| Format | Description | | ------------------ | ------------------ | | [start:end] | Basic slicing | | [start:end:step] | Step-based slicing |

12. Error Handling

do {
    define x = y
} track {
    sldeploy "Error occurred"
}

13. Imports

import math from "math"

Supported Imports

| Type | Description | | --------------- | --------------------- | | .sl files | Local modules | | Node.js modules | External dependencies |

14. Built-in Functions

Examples:

len([1,2,3])
upper("hello")
random(1, 10)

Categories

| Category | Examples | | -------- | ---------------- | | String | upper, lower | | Array | push, pop | | Math | random | | Utility | len |

15. Asynchronous Code

define data = await get("https://api.example.com")
sldeploy data

16. Object Construction

func Person(name) {
    this.name = name
}

define p = new Person("Alice")
sldeploy p.name

17. Comments

# This is a comment

18. Language Notes

| Behavior | Description | | ---------------- | --------------------------------- | | Undefined values | Treated as null | | Function return | Defaults to null if unspecified | | Data structures | Dynamic (arrays and objects) | | Error reporting | Includes line and column details |

19. Next Steps

• Explore built-in functions
• Write small programs
• Review full syntax reference
• Experiment with custom scripts

Keywords

starlight language, scripting language, programming language tutorial, interpreter language, CLI scripting, custom language design