starlight-cli

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