Syntax

This page covers the Kotlin syntax that Skotch currently compiles.

Declarations

Functions

fun add(a: Int, b: Int): Int {
    return a + b
}

// Expression body shorthand
fun multiply(a: Int, b: Int): Int = a * b

Variables

val name = "Skotch"          // immutable, type inferred
var count: Int = 0           // mutable, explicit type

Extension functions

fun Int.isEven(): Boolean = this % 2 == 0

fun main() {
    println(4.isEven())      // true
}

Local functions

fun main() {
    fun helper(x: Int): Int = x * 2
    println(helper(21))      // 42
}

Literals

Integers

val decimal = 42
val hex = 0xFF
val binary = 0b1010
val withSeparator = 1_000_000
val long = 100L

Note

The L suffix is recognized by the lexer. Full Long arithmetic is not yet implemented in the backends.

Strings

val regular = "hello\nworld"
val raw = """
    no escape processing
    preserves newlines
"""
val template = "value: $x"
val exprTemplate = "sum: ${a + b}"

Characters

val letter = 'A'
val newline = '\n'
val tab = '\t'

Booleans

val yes = true
val no = false

Operators

Category	Operators
Arithmetic	+ - * / %
Comparison	== != < > <= >=
Logical	&& || !
Unary	- (negation), ! (not)
Assignment	= += -= *= /= %=
String concat	+ (String + String, String + Int)

Comments

// Line comment

/* Block comment */

Semicolons

Semicolons are optional. Skotch uses newlines as statement terminators, consistent with standard Kotlin.