Crate knf 

Load, merge and emit layered JSON and TOML configuration.

Three steps, each a function, and a caller composes them:

1. load_layers reads each path into a Value, keeping the format it was read as;
2. merge folds the flat layer list from left to right — any in-memory overlays are just more layers appended to the list;
3. interpolate, if wanted, resolves ${...} references once, on the merged document.

format::emit renders the result. JSON and TOML appear only in format and value; the merge and interpolation never learn either exists.

No flag names. An error from this crate carries key paths and file paths; the command-line spelling that produced it is knf-cli’s to add. That is what LoadError exists for — the failures that have an obvious command-line remedy are typed, so the caller decides how to name them.

Re-exports

pub use format::Format;

pub use value::BadDatetime;

pub use value::IntegerOutOfRange;

pub use value::NonFiniteFloat;

pub use value::NullInToml;

pub use value::TomlError;

Modules

format

Format detection, parsing and emission.

value

Conversion between the merge IR and the native JSON/TOML value types.

Structs

Cycle

A reference that resolves, directly or indirectly, to itself.

EnvValue

An environment variable in both forms interpolation needs.

MergeOptions

Knobs on the merge itself. Passed by reference rather than encoded as cargo features: features are additive and unify across a dependency graph, so a strict feature would silently change behaviour for one consumer the moment a second consumer enabled it.

PathLeaf

A leaf value addressed by a parsed path.

ProcessEnv

Reads ${env:NAME} from the real environment.

RefPath

A parsed path: dotted keys plus bracket array indices, a.b[2].c.

Enums

InterpError

Why interpolation failed.

LoadError

Why a positional could not be turned into a layer.

MergeError

Number

A number, kept in the widest lossless representation of its source.

PathError

Why a path expression was rejected.

Problem

One thing wrong with one reference.

Seg

One step of a path into a document.

Syntax

A malformed reference.

Value

A parsed document, or any node within one.

Constants

STDIN

The positional that means “read stdin”.

Traits

Env

Where ${env:NAME} reads from.

Functions

interpolate

Resolves every reference in doc.

json_or_string

Parses text as JSON, falling back to the string itself.

load_layers

Reads and parses every positional into the merge IR, keeping the format each input was read as.

merge

Folds a list of layers into one document, seeded with an empty object.

merge_into

Merges over into base in place.

render_path

Renders a path for display: servers.primary.host, tags[0].

Type Aliases

Map

The object type. indexmap rather than BTreeMap so input key order survives, and rather than Vec<(String, Value)> so merge’s per-key lookup is not quadratic.