Implementation Status

The language reference describes Kairo as designed. This page lists where the current compiler falls short of it. Each entry is removed when the gap closes.

Not Compiled Yet

Feature	Status	Meanwhile
Vector literals (`var v: [i32] = [1, 2, 3]`)	Type-check and compile, but do not link: the built-in vector constructors are not implemented yet	Use an array `[T; N]` or a slice `[T;]`
Set literals `{a, b}`	Not compiled	—
Map literals `{k: v}`	Not compiled	—
File-scope `var`	Not compiled	Move the variable into a function, or use `eval` for constants
Initializing a `const` field in a constructor	Not supported	—

Checked by C++, Not by Kairo

Access control is enforced, but the error comes from the C++ compiler at build time rather than as a Kairo diagnostic. This covers priv constructors and writes to const fields.

Not Diagnosed

Passing a slice literal to a function that stores the slice is not caught. The literal’s storage ends with the statement, so the stored slice dangles. This becomes an error when Tether lands; until then, pass a var or a [T] to any function that keeps what it is given. See Primitives.

Three extend rules are not diagnosed yet:

A plain extend outside the type’s file, or an extend ... impl in neither the type’s nor the interface’s file, is accepted. See Same-File Restriction.
Calling an extension member whose bounds the type arguments do not satisfy is not reported at the call site. See Generic Extends.
An extend ... impl that is missing interface methods is not reported at the extend declaration. See Interface Conformance.

A generator that outlives the object it was created from, or an @inout argument it was given, is not caught; it dangles. This becomes an error when Tether covers generators. Until then, do not keep a generator longer than the object it came from.

Language Gaps

A Kairo string cannot be passed to a C const char* parameter; string.c_str() is planned. See C & C++ Interoperability.
Evaluation order is left to right for arguments, except for calls returning a C++ reference or class object and for primitive operators whose two operands both have side effects. See Operators.