Module locale 

Cross-platform language detection and resolution (Rules Rust i18n).

Precedence (highest → lowest) — four product layers

1. CLI --lang flag (validated BCP47; must negotiate to a supported locale)
2. Persisted preference (<config_dir>/lang, XDG; 0o600 when written) via locale set
3. OS locale via sys_locale::get_locale() (never raw LANG / LC_* in portável)
4. Fallback: Language::English (en)

SSH_CLI_LANG is a historical constant name only — not read as a product config store (G-AUD-12). Use --lang or locale set.

Pipeline

Raw string → strip encoding/modifier → _→- → LanguageIdentifier (unic-langid) → negotiate against available locales (fluent-langneg) → map to Language → publish once in OnceLock.

Detection failure is never silent: tracing::warn! records the miss (observability / stderr diagnostics; no remote telemetry).

Structs

LocaleResolution

Full resolution result (language + winning layer + raw inputs for diagnostics).

Enums

LocaleSource

Which precedence layer won resolution (diagnostics / locale subcommand).

Constants

LANG_PREFERENCE_FILE

File name for the persisted language preference (sibling of config.toml).

Functions

clear_persisted_lang

Removes the persisted language preference if present.

current_language

Returns the current global language.

lang_preference_path

Path to the persisted language preference file.

negotiate_code

Negotiates a raw code against the available product locales.

negotiate_langid

Negotiates a structured identifier against available locales.

normalize_raw_locale

Normalizes a raw locale string for BCP47 parse.

parse_lang_cli_arg

Clap value_parser for --lang: accepts BCP47 tags that negotiate to a supported product locale (en, en-US, pt-BR, pt, …).

parse_language_identifier

Parses a raw OS/CLI locale into a LanguageIdentifier.

read_persisted_lang

Reads the persisted language preference (trimmed, non-empty).

resolve_config_dir

Directory that holds config.toml / lang (respects override and XDG).

resolve_language

Resolves language using the CLI / XDG / OS / default precedence hierarchy.

resolve_language_detailed

Like resolve_language, but returns diagnostics for locale / tests.

set_language

Sets the global language (once at process startup).

write_persisted_lang

Writes the persisted language preference (BCP47 of a supported language).