Norm 0.3

Norm 0.3 is the nullable-safety and algorithm-foundation release. This page defines the 0.3 delivery contract; the language specification defines the complete semantics.

Nullable types

• Types are non-null by default and T? explicitly represents a nullable type.
• null receives a type from a nullable expected type.
• Nullable types are supported in fields, parameters, return types, locals, and nested generic arguments.
• Generic substitution normalizes repeated nullability.
• if, early return, &&, and || provide flow-sensitive narrowing for local variables.
• ?. propagates null across member reads and method calls.
• ?? evaluates a lazy fallback from left to right.
• Guest null has an explicit runtime representation shared by JVM and Native Image execution.

Calls and control flow

• Top-level functions, class methods, and built-in functions support overloads.
• Overload resolution selects one target by parameter count, labels, types, and generic inference.
• for condition { ... } re-evaluates a Boolean condition before every iteration.
• Conditional and iterable loops have distinct Syntax, Bound IR, and execution nodes.
• Both loop forms support break, continue, return, and execution cancellation checks.

Ranges and collections

• range(start, end, step) supports ascending, descending, and strided end-exclusive integer ranges.
• range(start, end) uses a step of one.
• Range.size() uses the same direction and boundary rules as iteration.
• Array<T> and List<T> provide last() and reversed().
• List<T> provides removeLast().
• Array.filled and List.filled use general type-member lookup and generic inference.
• Map.get(key:) returns a nullable value while indexed reads continue to require an existing key.
• Collection copying, reversal, and filling follow the existing value-transfer semantics.

Text and sorting

• CodePoint.isAsciiDigit() and CodePoint.asciiDigitValue() provide explicit ASCII digit operations.
• std.collections.sort provides stable natural ordering for Array and List values containing Integer, CodePoint, or String.
• Sorting returns an independent collection and String ordering uses Unicode code points.

Tooling and executable specification

The CLI, SemanticModel, Bound IR, Truffle backend, and language server share the same nullable, overload, type-member, and loop bindings. Diagnostics, completion, signature help, hover, navigation, references, and rename cover the 0.3 syntax and cross-file public signatures.

Executable specifications cover flow joins and reassignment, safe-access evaluation order, nullable generics, overload ambiguity, conditional-loop control transfer, Range boundaries and integer overflow, errors for empty collections, element-copy semantics, Unicode digit boundaries, stable sorting, and the LeetCode 1–100 regression suite.