Syntax Overview

The core syntax of ScarScript — declarations, operators, control flow, loops, and strings.

Comments

// Single-line comment
/* Multi-line
   comment */

Variables

Three declaration kinds. Variables are immutable by default — use mut when you need to reassign.

Keyword	Mutable	Use Case
`val`	No	Most variables — single assignment
`mut`	Yes	Counters, accumulators, loop state
`const`	No	Compile-time constants (requires type)

// With explicit type annotation
val name: str = "Zawiyar"
mut count: int = 0
const MAX: int = 100

// With type inference (recommended)
val age = 25          // int
val price = 99.99       // dec
val active = true       // bool
val label = "hi"        // str

Inference rules: 42 → int, 3.14 → dec, "text" → str, true → bool. If inference fails, the compiler reports cannot infer type.

Operators

Arithmetic

Operator	Description	Example
`+`	Addition / concatenation	`2 + 3` → `5`
`-`	Subtraction	`10 - 4` → `6`
`*`	Multiplication	`6 * 7` → `42`
`/`	Division	`10 / 2` → `5`
`%`	Modulo	`10 % 3` → `1`

int + dec: Mixing an int with a dec automatically widens the int (1 + 2.5 → 3.5). Mixing int with str is a type error.

Comparison

Operator	Description
`==`	Equal
`!=`	Not equal
`<` `<=` `>` `>=`	Ordering

Logical

Operator	Description	Example
`and`	Logical AND	`age >= 18 and active`
`or`	Logical OR / fallback	`sys.env("PORT") or "8080"`
`not`	Logical NOT	`not flag`

JS-style or fallback: When the left side is empty/zero/false, or returns the right side. This is how you provide defaults without if-statements.

Control Flow

if / else if / else

val age = 20

if age < 13 {
    print("child")
} else if age < 18 {
    print("teen")
} else {
    print("adult")
}

Conditions must be bool. There are no truthy/falsy conversions in if.

Loops

ScarScript has a single universal for keyword that covers every loop pattern.

Numeric range

for i in 0..5 {
    print(i)          // 0 1 2 3 4 (end exclusive)
}

Iterate a collection

val items = ["fast", "backend", "express"]

for item in items {
    print(item)
}

Key-value iteration

for k, v in config {
    print("{k} = {v}")
}

Condition loop (while-style)

mut n = 0
for n < 10 {
    n = n + 1
}

There is no separate while keyword — for condition { ... } covers that use case entirely.

Strings

String interpolation

Embed expressions directly inside double-quoted strings with { }:

val name = "Zawiyar"
val age = 25

print("User {name} ki age {age} hai.")
// User Zawiyar ki age 25 hai.

Common operations

val s = "hello"

s.len()          // 5
s.upper()        // "HELLO"
s.lower()        // "hello"
s.contains("ell") // true

Arrays

val nums = [1, 2, 3, 4, 5]

nums.len()          // 5
nums[0]             // 1
nums.push(6)        // append (on mut arrays)

for n in nums {
    print(n)
}

Reserved Names

These identifiers cannot be used as variable or function names:

Category	Names
Functions	`print`, `log`
Modules	`math`, `file`, `sys`, `time`
Go keywords	`func`, `return`, `if`, `else`, `for`, `range`, `var`, `const`, `type`, `import`, etc.
Prefix	Any name starting with `_`

Using a reserved name produces: error: "print" is a builtin — cannot be redeclared.