Language Basics

This page describes the current state of the Klar language. Klar is strict by design, prioritizing explicitness over convenience to ensure code safety and clarity.

Strictness Policy

Klar requires:

• Explicit modifiers
• Explicit types
• Explicit returns
• Explicit control-flow termination

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File Extension

The official extension for Klar source files is .kl(recommended) or .klar.

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Comments

Klar supports both single-line and block comments:

// This is a single-line comment

/*
  This is a 
  block comment
*/

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Types (Current)

Klar maps its primitive and reference types directly to Java:

Klar Type	Java Equivalent	Category
integer	int	Primitive
double	double	Primitive
boolean	boolean	Primitive
character	char	Primitive
String	java.lang.String	Reference
void	void	Return Only
null	null	Value Only

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Variables

Variable declaration in Klar is strictly enforced. You must provide a type and an initial value; uninitialized variables are not permitted.

integer score = 0;
double price = 99.90;
String name = "Klar";
character initial = 'K';
boolean isActive = false;

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Functions

A function definition requires a specific structure to be valid:

1. @Use("java"): Mandatory in the current version.
2. Access Modifier: Explicit (currently public is the standard).
3. Return Type: Must be explicitly stated.
4. Explicit Return: All code paths must terminate with a return statement.

The main Entrypoint

@Use("java")
public void main() {
    println("Hello World From Klar!");

    return null; 
}

Return Rules

• All functions must return explicitly.
• In void functions, return; and return null; are currently accepted, though return null; is the current recommendation for consistency.
• Missing a return statement will trigger a Semantic Diagnostic.

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Operators

Supported

• Comparisons: ==, !=, <, >, <=, >=
• Arithmetic: +, -, *, /, %
• Logical: and, or (Note: && and || are NOT supported)

Intentionally Not Supported (Syntax Sugar)

• ** (Power operator): Use standard library functions instead.
• Implicit numeric conversions: You cannot assign an integer to a double without an explicit operation.

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Built-ins

• print(...)
• println(...)
• printf(...) (Currently a placeholder)

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Roadmap: What is Missing

The following features are currently not implemented:

• Arrays and Collections
• Structs / User-defined types
• Module imports / Cross-file linking
• Type Casting