sim-value

sim-value is the ergonomic construction and access layer for the kernel Expr graph. It gives SIM libraries one shared way to build values, read fields, update maps immutably, classify variants, parse capability-name expressions, and address nested data by path.

The crate does not extend the kernel data model and does not add runtime policy. It depends only on sim-kernel, so higher libraries can use the same helpers without pulling in concrete behavior.

What it provides

• Constructors for symbols, qualified symbols, numbers, strings, lists, vectors, and maps.
• Field readers for bare-symbol keys and mixed symbol/string keys.
• Required-field helpers with consistent diagnostics.
• Immutable update helpers for maps and nested paths.
• The shared expr_kind classifier and capability-name parser.
• Side-effect-free text edit helpers for exact and line-range edits.

Example

use sim_value::access::{field, set};
use sim_value::build::{int, map};

let value = map(vec![("a", int(1)), ("b", int(2))]);
let updated = set(&value, "a", int(9));

assert_eq!(field(&updated, "a"), Some(&int(9)));
assert_eq!(field(&updated, "b"), Some(&int(2)));

Examples, Docs, And Validation

Rustdoc examples cover the construction, access, update, and path helpers. The crate has no recipe directory because it stays at the value-substrate layer.

• API docs: https://docs.rs/sim-value
• Repository guide: https://github.com/sim-nest/sim-foundation

From the sim-foundation checkout:

cargo test -p sim-value
RUSTDOCFLAGS="-D warnings" cargo doc -p sim-value --no-deps
cargo run -p xtask -- check-recipes
cargo run -p xtask -- check-package-floors
cargo run -p xtask -- simdoc --check