`saveobj` — Return the MAT-file serialization payload for an object.

saveobj(a) returns the payload that save should write for object a. If the object's class registers a saveobj method, RunMat dispatches to that method. Otherwise RunMat returns a scalar struct containing the object's stored public runtime properties.

Syntax

b = saveobj(a)

Inputs

Name	Type	Required	Default	Description
`a`	`Any`	Yes	—	Object to serialize.

Returns

Name	Type	Description
`b`	`Any`	Serialized object representation.

Errors

Identifier	When	Message
`RunMat:ObjectSerialization:InvalidArgument`	The input is not an object or serialized object envelope.	`object serialization: invalid argument`
`RunMat:ObjectSerialization:Dispatch`	A saveobj or loadobj method cannot be resolved or executed.	`object serialization: method dispatch failed`
`RunMat:ObjectSerialization:RecursionLimit`	Object serialization nesting exceeds the supported recursion limit.	`object serialization: recursion limit exceeded`

How `saveobj` works

The public signature is b = saveobj(a).
Object and handle-object inputs dispatch to a registered Class.saveobj method when one is available.
When no registered overload exists, RunMat serializes the object's stored property map as a scalar struct.
Nested objects inside structs or cells are serialized recursively before MAT-file encoding.
save automatically applies this object serialization path before writing MAT-file variables.
Recursion is bounded and reports RunMat:ObjectSerialization:RecursionLimit for cyclic or excessively nested object graphs.
Non-object inputs to direct saveobj raise RunMat:ObjectSerialization:InvalidArgument.

Does RunMat run `saveobj` on the GPU?

saveobj does not launch provider kernels.

save remains the residency sink for any GPU values that appear inside the serialized payload.

GPU memory and residency

saveobj itself is host-side object metadata work. If a serialized payload contains GPU-resident numeric properties, save gathers those values when it converts the payload to MAT-file arrays.

Examples

Return a default property payload

obj = new_object('Point');
payload = saveobj(obj)

Save an object through MAT-file serialization

obj = new_object('Point');
save('object_state.mat', 'obj')

Using `saveobj` with coding agents

Open a RunMat example with live inputs, then ask the agent to explain how saveobj changes the result.

Run a small saveobj example, explain the result, then change one input and compare the output.

FAQ

Does save call saveobj automatically?⌄

Yes. Before MAT-file encoding, RunMat walks selected values and applies registered saveobj methods for object and handle-object values.

What is saved when no class-specific method exists?⌄

RunMat writes the current runtime property map in an internal object envelope so load can reconstruct an object with the same class name and stored properties.

Are handle identities preserved?⌄

No. Current support serializes the referenced object's properties. It does not preserve handle identity, listener state, or aliasing relationships across save/load.

Serialization

loadobj

Indexing

numArgumentsFromSubscript · subsasgn · subsref

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how saveobj is executed, line by line, in Rust.

View the source for saveobj in Rust on GitHub
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Found a bug? Open an issue with a minimal reproduction.

About RunMat

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saveobj — Return the MAT-file serialization payload for an object.