Syntax Catalog - Clean Language

Variable Declaration

Variables

integer count = 42
string name = "Clean"

Declare variables with explicit type annotations. Clean Language uses indentation-based syntax and requires type declarations for safety.

Function Declaration

Functions

functions:
    integer add(integer a, integer b)
        return a + b

Define functions with typed parameters and return types. Functions must be declared in a functions: block and use indentation-based syntax.

Class Declaration

Classes

class Animal
    properties:
        string name
        integer age
    methods:
        string describe()
            return name + " is " + _itos(age)

Define classes with properties and methods blocks. Clean Language supports object-oriented programming with clean, indentation-based syntax.

If Statement

Control Flow

if score > 90
    grade = "A"
else if score > 80
    grade = "B"
else
    grade = "C"

Conditional execution using indentation-based syntax. No parentheses or braces needed - Clean Language uses clean, readable control flow.

For Loop

Control Flow

for integer i = 0, i < 10, i + 1
    _print(_itos(i))

Iterate with initialization, condition, and increment expressions separated by commas. Clean's for loops use indentation-based blocks.

Async Function

Async

async functions:
    string fetchData()
        string result = await _http_get(url)
        return result

Define asynchronous functions in an async functions: block. Use await to wait for async operations to complete before continuing execution.

Import Statement

Modules

plugins:
    frame.httpserver
    frame.data

Import plugins and modules using the plugins: block. Clean Language uses a simple module system for organizing and reusing code.

Try-Catch Block

Error Handling

onError
    _print("Something went wrong")
    _print(_error_message())

Handle errors using the onError block. Clean Language provides built-in error handling functions like _error_message() to access error details.