F. Storage and Memory

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Feature	Status	Notes
State variables	✅	Mapped to Neo Storage with prefix-based keys.
constant	✅	Compile-time constants inlined.
immutable	✅	Tracked via is_immutable flag. Modification blocked at compile time.
memory keyword	✅	Parsed. NeoVM is stack-based so memory is implicit.
storage keyword	✅	Storage references for mappings and state variables.
calldata keyword	✅	Parsed. Treated as memory — NeoVM has no calldata region.
Nested mappings	✅	mapping(K1 => mapping(K2 => V)) with composite storage keys.
Struct in storage	✅	Serialized/deserialized via StdLib.serialize/StdLib.deserialize.
Array .push() / .pop()	✅	Storage array operations supported.
Array .length	✅	Both memory and storage arrays.
new bytes(n) / new string(n)	✅	Buffer allocation via NEWBUFFER.
new T[](n)	✅	Dynamic array allocation via NEWARRAY.
new Contract(...)	⚠️	Does not deploy on Neo; constructor-like logic is inlined/simulated and a zero-address placeholder is produced. Use ContractManagement.deploy(...) for real deployment.

Contract creation via new

new Contract(...) is accepted for source compatibility, but it does not perform Neo contract deployment. The current lowering inlines/simulates constructor-like logic when the contract is available in the compilation graph and returns a zero-address placeholder. For real child-contract deployment, compile the target contract separately and call ContractManagement.deploy(nef, manifest, data).

Storage key derivation

State variables are stored in Neo Storage using deterministic key derivation. For simple state variables, the key is derived from the variable name. For mappings, the key is computed as:

SHA256(key_bytes || slot_hash)

Where slot_hash is SHA256(variable_name). Nested mappings iterate this process for each key level. See Types for the full storage lowering specification.

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