Boundary integration

All external-input APIs in matten are Result-zone: they never panic on malformed data and always return Result<Tensor, MattenError>.

JSON

Canonical object form

The preferred form for programmatic use — unambiguous for any rank:

#![allow(unused)]
fn main() {
use matten::Tensor;

let t = Tensor::from_json(
    r#"{"shape":[2,2],"data":[1.0,2.0,3.0,4.0]}"#
).unwrap();
assert_eq!(t.shape(), &[2, 2]);
}

Convenience nested-array form

Rank 1 and rank 2 nested arrays are also accepted:

#![allow(unused)]
fn main() {
let t = Tensor::from_json("[[1.0,2.0],[3.0,4.0]]").unwrap();
assert_eq!(t.shape(), &[2, 2]);

let v = Tensor::from_json("[1.0,2.0,3.0]").unwrap();
assert!(v.is_vector());
}

Ragged arrays and non-numeric values return MattenError::Parse:

#![allow(unused)]
fn main() {
assert!(Tensor::from_json("[[1.0,2.0],[3.0]]").is_err()); // ragged
assert!(Tensor::from_json(r#"[[1.0,"text"]]"#).is_err()); // non-numeric
}

Serde integration

Tensor implements Serialize and Deserialize using the canonical object form (requires the serde or json feature, both on by default):

#![allow(unused)]
fn main() {
use matten::Tensor;

let t = Tensor::new(vec![1.0, 2.0, 3.0, 4.0], &[2, 2]);
let json = serde_json::to_string(&t).unwrap();
let t2: Tensor = serde_json::from_str(&json).unwrap();
assert_eq!(t, t2);
}

File loading

#![allow(unused)]
fn main() {
let t = Tensor::load_json("examples/data/tensor_2x2.json")?;
}

File errors map to MattenError::Io; parse errors to MattenError::Parse.

CSV

Numeric CSV ingestion accepts rectangular numeric-only CSV. Shape is inferred as [rows, cols].

#![allow(unused)]
fn main() {
let t = Tensor::from_csv("1.0,2.0,3.0\n4.0,5.0,6.0\n")?;
assert_eq!(t.shape(), &[2, 3]);
assert_eq!(t.as_slice(), &[1.0, 2.0, 3.0, 4.0, 5.0, 6.0]);
}

Errors include row and column context:

matten csv parse error: at row 1, column 1: expected f64, got "active"

#![allow(unused)]
fn main() {
let t = Tensor::load_csv("examples/data/numeric_2x3.csv")?;
}

Cargo features

Lean install (no I/O dependencies):

matten = { version = "0.28", default-features = false }

Error mapping