Crate tanzim_value 

tanzim-value

Package | Documentation | Repository

Foundational value types for the tanzim pipeline.

Types

• Value — Bool, Int, Float, String, List, Map, Null
• LocatedValue — Value + Location (full originating tanzim_source::Source, optional 1-based line/column)
• Map — ordered Vec-backed map; last inserted key wins on lookup
• Error — parse-time and (with the serde feature) deserialize errors; use {error:#} for a source snippet with caret underline

Location

Location holds the full originating tanzim_source::Source (name, options, resource, including any on_error policy) so any value or error can be traced back to how it was declared. Positions (line, column, length) are 1-based and stored as Option<NonZeroU32>. Error boxes its Location field so results stay small enough to return by value without tripping clippy::result_large_err. Construct via Location::in_source (real source) or Location::at (bare name/resource for synthetic origins); neither exposes NonZeroU32 to callers.

Example

use tanzim_value::{Value, LocatedValue, Location, Map};

let mut map = Map::new();
let location = Location::at("env", "", None, None, None);
map.insert(
    "port".to_string(),
    LocatedValue::new(Value::Int(8080), location.clone()),
);
map.insert(
    "host".to_string(),
    LocatedValue::new(Value::String("localhost".to_string()), location),
);
assert!(map.contains_key("port"));
assert_eq!(map.len(), 2);

Deserializing into your own types (serde feature)

With the optional serde feature, Value and LocatedValue implement serde::Deserializer, so a config tree turns straight into your own structs. A LocatedValue runs the same Value deserializer but, on failure, stamps the offending node’s Location onto the error:

use serde::Deserialize;
use tanzim_value::{Value, LocatedValue, Location, Map};

#[derive(Deserialize)]
struct Server {
    host: String,
    port: u16,
}

// `tree` is a `LocatedValue` a parser would produce, here the map
// `{ host: "localhost", port: 8080 }` located at `server.json`.
let server: Server = tree.try_deserialize().unwrap();
assert_eq!(server.host, "localhost");
assert_eq!(server.port, 8080);
// On a type mismatch: `Err(Error::Deserialize { .. })` whose `Display` points at
// `source:resource:line:column`.

Features

Feature	Enables
serde	serde::Deserializer for Value/LocatedValue + try_deserialize::<T>(), and serde::de::Error for Error

Off by default.

Relations

• Used by all other tanzim crates.
• tanzim-parse produces LocatedValue trees from raw bytes.
• tanzim-merge consumes LocatedValue trees to produce merged maps.

Structs

Comment

Comment text attached to a LocatedValue: lines preceding the key and an optional inline comment on the same line as the value.

LocatedValue

A Value with its Location and an optional Comment.

Location

Source and optional position of a configuration value.

Map

Ordered map of configuration keys to located values (last key wins on lookup).

Enums

Error

Error while deserializing configuration input.

Value

Dynamically typed configuration value.

ValueType

Kind of value stored in Value.