Error Reference

General lexer error — unexpected character or malformed token.

Unrecognized character in source. Check for typos or paste artifacts.

String literal not closed. Add a closing ".

let s = "hello   // ❌ missing closing quote
let s = "hello"  // ✅

Syntax error — unexpected token. Check brackets, keywords, and spacing.

Got a token that doesn't fit here. Common causes: missing {, extra keyword, wrong operator.

Expected a token (like ) or }) but found something else.

fn f(x  { return x }  // ❌ missing )
fn f(x) { return x }  // ✅

Mismatched {} [] (). Count your opening and closing brackets.

Type or scope error found by the static analyzer before execution.

Variable/function not declared in this scope.

print(x)        // ❌ x not defined yet
let x = 5
print(x)        // ✅

Name already defined in this scope. Rename or use a different scope.

Value doesn't match the declared type annotation.

let x: int = "hello"   // ❌ string ≠ int
let x: int = 42        // ✅

General runtime error — method not found, wrong argument type, etc. The most common error. Check the message for the specific cause.

Operation on wrong type.

let x = 5 + "hello"  // ❌ int + string
let x = 5 + 10       // ✅

Undefined variable at runtime. Did you mean: hint shown if similar name exists.

Array index out of bounds.

let a = [1,2,3]
print(a[5])   // ❌ index 5 out of range (len=3)
print(a[2])   // ✅ last element = 3

Module not found. Check the module name — use .modules in REPL to see all 59 available modules.

Integer division by zero. Use float division if you want Infinity: 1.0 / 0.0 = Infinity.

Too deep recursion. Add a base case or increase the limit.

Non-exhaustive match — no arm matched. Add case _ { } as a wildcard.

Accessed field/method on nil. Use ?.  optional chaining or check with x != nil.

assert(cond, msg) failed. The catch variable receives the message string directly.

panic(msg) called. Use for truly unrecoverable states.

unreachable(msg) reached. This is a programmer error — the code path was supposed to be impossible.