Changelog

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All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[0.32.0] — May 12th, 2026

Bug Fixes

  • mix localize.download_locales no longer evaluates config/runtime.exs of the consumer application. Previously the task ran Mix.Task.run("app.config"), which transitively evaluated runtime.exs, which was not necessary. The task now loads only compile-time config (config/config.exs and any imported env-specific file), matching the build-time contract its docstring already advertised. Thanks to @whatyouhide for the PR.

  • Hardened two further sites that pattern-matched {:ok, _} = <fallible Localize call> and could have surfaced the same MatchError class as issue #26: the per-unit format loop in Localize.Duration.to_string/2 now short-circuits on the first formatter error, and Localize.Number.Formatter.Decimal's digit-transliteration step now uses with to fall through to untransliterated digits if either the requested or :latn number-system data is unavailable.

Hardening

  • New Localize.LintTest source-level lint that scans lib/ and fails the test suite if any file pattern-matches {:ok, _} = against a known-fallible Localize call. The list of fallible calls and an empty allowlist live in the test; future occurrences fail loudly on the offending PR rather than waiting for a runtime regression report.

  • New Localize.Locale.FallbackResilienceTest exercises the load → store → get pipeline for seven representative regional locales under a provider that only serves :en, asserting that the data ends up under the canonicalised requested key and that provider.get/3 succeeds.

  • New Mix.Tasks.Localize.DownloadLocalesTest calls DownloadLocales.banner/2 directly with default_locale: :"en-ZA" set, reproducing the exact scenario from issue #26 without invoking the network. banner/2 is now @doc false so the test can reach it.

[0.31.0] — May 12th, 2026

Bug Fixes

  • Localize.Locale.Loader now stores fallback locale data under the requested locale id rather than the resolved fallback id, restoring 0.29 behaviour. The regression introduced in 0.30.0 caused provider.get(requested_locale, _) to miss in-memory fallback data and surface as a spurious ItemNotFoundError — most visibly crashing mix localize.download_locales with a MatchError when default_locale named an unavailable locale. Locked down with test/localize/locale/loader_fallback_test.exs. Closes #26.

  • mix localize.download_locales no longer pattern-matches on the result of Localize.Message.format/2 when building its progress banner; if formatting fails for any reason the task falls back to a plain ASCII banner and continues with the actual download.

Behaviour Changes

[0.30.1] — May 12th, 2026

Bug Fixes

  • Revert the [:safe] option on :binary_to_term/2 since we cannot guarantee all the required atoms are materialized at application start. Thanks to @bigardone for the report. Closes #25.

[0.30.0] — May 12th, 2026

Security

  • Localize.LanguageTag.parse/1 no longer calls String.to_atom/1 on raw parser output, closing an atom-table-exhaustion DOS vector on untrusted locale inputs. Atomisation is now gated behind the CLDR validity sets after alias resolution, and unrecognised language/script/territory subtags return Localize.InvalidSubtagError.

  • Localize.Locale.to_locale_id/1 renamed to Localize.Locale.cldr_locale_id_from/1 and now returns {:ok, atom()} | {:error, Exception.t()}, gating atom creation behind Localize.validate_locale/1 and closing a second atom-table-exhaustion vector on locale inputs.

  • Localize.Currency.validate_currency/1, territory_currencies/1, current_currency_for_territory/1, and the binary-code branch of currencies_for_locale/3's filter no longer atomise input before checking validity. Unknown currency or territory binaries are rejected via Helpers.existing_atom/1 and never grow the atom table.

  • Localize.Script.display_name/2 and Localize.Unit.Formatter no longer atomise binary input before checking validity. Unknown script codes return Localize.UnknownScriptError without growing the atom table; the unit formatter's currency atomisation is gated as defence-in-depth behind the upstream Localize.Unit.validate_currency_codes/1 check.

  • MF2 :list function and unit parser no longer atomise user-controlled binaries. The :list function's binary style= fallthrough now sets a sentinel atom that surfaces as an InvalidValueError in Localize.List, and SI prefix names are resolved through a compile-time lookup map (Localize.Unit.Data.si_prefix_atom/1) rather than String.to_atom/1 at parse time.

  • Localize.Number.System (system_name_from/2, number_system_digits/1, to_system/2), Localize.Number.Symbol.number_symbols_for/2, and the datetime-formatter's time_preferences_for/1 no longer atomise user-supplied binary number-system or locale names before validation. Lookups go through Helpers.existing_atom/1 against pre-atomised CLDR data sets.

  • Closed additional Atom DOS vectors in Localize.Locale.LocaleDisplay.display_name/2 (now routes through cldr_locale_id_from/1), Localize.Territory.Subdivision.display_name/2, the -u-co- and -u-kr- extension parsers in Localize.Collation.Options, and the redundant String.to_atom(to_string(...)) round-trip in plural-rule fallback.

  • Closed three further atom-DOS sites called out by the security audit's findings 1.4 and 1.5: LocaleDisplay.U.find_exemplar_city/2 (-u-tz- IANA region/city splitter), LocaleDisplay.T.to_atom_safe/1 (-t- extension subtag normalisation), and Gettext.Interpolation.safe_to_atom/1 (missing-binding name reporting). All three previously fell through to String.to_atom/1 on a miss, which defeated the helper's name; they now return the original binary unchanged when no atom exists.

  • Locale cache files and downloaded ETFs are decoded with :erlang.binary_to_term(_, [:safe]). Closes a node-crash vector for any deployment with :locale_cache_dir set to a writable directory: a malicious or corrupted cache file can no longer resurrect arbitrary atoms, funs, or refs. Failed safe decodes surface as LocaleNotFoundInCacheError (or LocaleDownloadError for the download path) and the file is treated as stale.

  • Public parser entry points now reject oversized input before invoking the grammar, capping the parser's CPU exposure on hostile input. Defaults are 256 bytes for Localize.LanguageTag.parse/1 and Localize.Unit.Parser.parse/1, 64 KB for Localize.Message.Parser.parse/1, and 1 KB for Localize.Number.Parser.parse/2. Each cap is configurable via app env (:max_locale_id_bytes, :max_message_bytes, :max_unit_bytes, :max_number_bytes). Number.Parser.parse/2 additionally rejects Decimal results whose exponent magnitude exceeds :max_decimal_exponent (default ±100) so downstream multiplication or formatting cannot materialise huge mantissas.

  • Localize.FormatCache ETS table switched from :public to :protected; writes are routed through the cache GenServer. The size cap (:format_cache_max_entries, default 2 000) is now enforced synchronously on each insert rather than by a 10-second sweeper, replacing the previous biased-random eviction that could leave the cache oversized. New Localize.FormatCache.clear/0 and size/0 helpers added for tests and maintenance.

  • NIF (ICU bindings) hardened. All NIF entries except nif_plural_rule now run on the dirty CPU scheduler pool (ERL_NIF_DIRTY_JOB_CPU_BOUND); the collator pool is sized for schedulers + dirty_cpu_schedulers and reserve_coll refuses overflow rather than reading past the array end. The reorder-codes branch caps numCodes at 256 and checks enif_alloc before use; every std::stoll/std::stod/std::stoi is wrapped in try/catch so out-of-range C++ exceptions cannot unwind through the NIF boundary; the hand-rolled JSON arg parser guards each access after skip_ws; per-call input lengths are capped at the NIF boundary (MAX_MF2_BYTES = 64 KB, MAX_COLLATION_BYTES = 1 MB, MAX_NUMBER_STR_BYTES = 1 KB).

  • Localize.Unit.CustomRegistry.load_file/1 now refuses to evaluate the file in :prod (or any environment without a loaded Mix module — typical for releases) unless config :localize, :allow_runtime_unit_files, true is explicitly set. Outside :prod the function works as before. The flag exists so an unintended feature switch in production cannot accidentally surface arbitrary code execution via Code.eval_file/1.

  • :localize_locale_cache ETS table switched from :public to :protected, owned by Localize.Locale.Loader. Writes are routed through the owner via cast (so the hot validate path doesn't block and writes triggered from inside the owner's own handle_call cannot deadlock). Reads remain direct ETS lookups. Combined with the format cache fix above, both ETS caches are now :protected against multi-tenant or other-library interference.

  • Localize.Utils.Http.get/2 and get_with_headers/2 now reject responses larger than 50 MB by default (configurable via :max_http_body_bytes app env or per-call :max_body_bytes option). Without the cap a malicious or compromised CDN could feed a multi-gigabyte response and OOM the BEAM. Oversized responses log an error and return {:error, :response_too_large}. Additionally, when peer certificate verification has been disabled (via LOCALIZE_UNSAFE_HTTPS), a one-time Logger.warning is emitted so a misconfigured production deployment cannot silently downgrade TLS without leaving an audit trail.

[0.29.0] — May 11th, 2026

Behaviour Change

Enhancements

[0.28.0] — May 9th, 2026

Behaviour Change

  • Localize.Interval.to_string/3 Date intervals (style :date, the default) now resolve their skeleton per-locale instead of using a hard-coded locale-independent mapping. The interval looks up Localize.DateTime.Format.date_formats(locale_id)[format] — the same mapping Localize.Date.to_string/2 uses — so date intervals follow the same conventions as single dates for the same :format. Visible effect on locales whose single-Date skeletons differ from the previous Interval table — most notably:
    • ja :medium is now numeric ("2012/01/05～2012/01/06"), aligning with single Date :medium ("2012/01/05"); was previously the abbreviated month form "2012年1月5日～6日". The richer Japanese-character form is now :long (matching single Date :long).
    • de :medium is now numeric ("15.01.2022 – 20.03.2022"); was previously the abbreviated month form. To get "15. Jan. – 20. März 2022" request the :yMMMd skeleton explicitly.
    • en :long uses full month name with no weekday ("January 5, 2012 – January 6, 2012"); was previously the :yMMMEd form "Thu, Jan 5 – Fri, Jan 6, 2012". The weekday now appears at :full. Per-locale skeletons that aren't shipped in CLDR's interval_formats data fall back to formatting each endpoint with Localize.Date.to_string/2 and joining via the locale's interval_format_fallback template. Non-:date styles (:month, :month_and_day, :year_and_month) remain locale-independent — they describe a deliberate field selection unrelated to standard date styles. The static Localize.Interval.date_styles/0 no longer includes a :date entry.

Bug Fixes

[0.27.0] — May 8th, 2026

Bug Fixes

  • Fix Localize.Interval.to_string/3 :short time-interval format using the wrong hour cycle on 24-hour locales. :short now picks :hm or :Hm per the locale's preferred hour cycle (honouring any -u-hc- Unicode-extension override), matching the cycle used by Localize.Time.to_string/2 :short. Thanks to @woylie for the follow-up report. Fixes #22.

  • Fix Localize.Time.to_string/2 silently ignoring the -u-hc- Unicode-extension override on the locale. The override now applies to both standard formats (:short/:medium/:long/:full) — remapped to the locale's cycle-appropriate :hm/:hms/:hmsv (12-hour, with the locale's AM/PM marker) or :Hm/:Hms/:Hmsv (24-hour) skeleton — and to user-supplied skeleton atoms like :Hms, where the hour symbols are substituted.

  • Fix zone-field artefacts on %Time{} standard formats. A Time carries no zone information, so Localize.Time.to_string/2 now strips zone characters (z, Z, O, v, V, x, X) from the resolved skeleton ID before formatting. Localize.Time.to_string!(~T[21:00:00], format: :long, locale: :ja) returns "21:00:00" (was "21:00:00 " — trailing space), and :es :full returns "21:00:00" instead of "21:00:00 ()" (parens around the empty zone field).

  • Adds support for Decimal version 3.0 to address a CVE. Thanks to @mitchellhenke for the PR.

Enhancements

[0.26.0] — May 6th, 2026

This release fixes user-reported bug #22 in time interval formatting and a number of RBNF conformance bugs arising from a more complete conformance testing process. The RBNF bugs have been around unreported and undiagnosed for many years.

Breaking Change

  • The default Localize.Interval.to_string/3 format output (which is :medium) for time-only inputs now includes seconds. Localize.Interval.to_string!(~T[12:00:00], ~T[14:00:00], locale: :ja) shifts from 午後0時00分～2時00分 to 12:00:00～14:00:00. :en's :medium shifts from 12:00 – 2:00 PM to 12:00:00 PM – 2:00:00 PM. Users who relied on no-seconds output should explicitly pass time_format: :short.

Bug Fixes

  • Fix Localize.Interval.to_string/3 collapsing the :short, :medium, :long, and :full time styles to the same :hm skeleton on Time inputs. :short keeps CLDR's interval-format dispatch (collapsed AM/PM); :medium and above route through the locale's per-style time-format pattern, restoring per-style differentiation and including seconds in the default :medium output. Thanks to @woylie for the report. Fixes #22.

  • Fix :time_format being silently ignored on Localize.Interval.to_string/3 for Time inputs. The option now takes precedence over :format, matching the precedence used on datetime intervals. Thanks to @woylie for the report. Fixes #22.

  • Fix Localize.Interval.to_string/3 crashing with FunctionClauseError when called with a binary :format (or :time_format) on Time inputs. Binary patterns are now applied to both endpoints and joined via the locale's interval-format fallback template, matching the behaviour of datetime intervals. Thanks to @woylie for the report. Fixes #22.

  • RBNF parser now distinguishes >> from >>> so CJK locales emit fractional digits without an inter-digit separator — Localize.Number.Rbnf.to_string(3.14, "spellout-numbering", locale: :zh) is 三点一四 instead of 三点一 四.

  • RBNF leading and embedded zeros in fractional digits, and very small magnitudes, are now preserved — 0.05 en is "zero point zero five", 3.04 zh is 三点〇四, and 0.000001 en is "zero point zero zero zero zero zero one".

  • RBNF 0.x special-base rule now matches when the integer part is zero and the value is non-zero, routing ko 0.5 spellout-numbering through its locale-correct sino-Korean 영점오 instead of the previous x.x-fallback 공점공오.

  • RBNF negative floats no longer double their output or silently drop the sign — ko -0.5 spellout-numbering is -영점오 instead of 공점공점오, and locales that lack a -x rule now get an ASCII - prefix.

  • RBNF integer <#,##0< quotient and float >%name> / >#,##0> / <%name< modulo and quotient no longer crash, completing case-clause coverage for every TR35 substitution-argument shape.

  • RBNF $(cardinal,…) and $(ordinal,…) plural-keyed substitutions now use the requested locale's plural rules instead of hard-coding English — fr Localize.Number.Rbnf.to_string(21, "digits-ordinal-masculine", locale: :fr) is "21e" instead of "21er".

  • RBNF fraction-with-rule numerator/denominator algorithm is now spec-correct — ky 1.5 spellout-cardinal is бир бүтүн ондон беш instead of бир бүтүн беш.

Enhancements

  • Add :minimum_significant_digits and :maximum_significant_digits options to Localize.Number.to_string/2.

  • Localize.Number.Rbnf.to_string/3 now accepts Decimal inputs in addition to native integers and floats, with whole-valued Decimals routed through the integer path with no precision loss.

  • RBNF >>> integer modulo now applies the source-preceding rule per TR35 §RBNF_Syntax, closing a latent gap; no current CLDR locale exercises this path.

[0.25.0] — May 1st, 2026

Bug Fixes

  • Fix en-CA :short date crash; teach :prefer about CLDR variant/standard alts. Thanks to @dabaer for the report. Closes #21.

Enhancements

  • Module refactoring to remove many compile-time cycles.

[0.24.0] — April 29th, 2026

Bug Fixes

  • Localize.DateTime.Formatter stand-alone pattern helpers now pass context: :stand_alone to Localize.Calendar.localize/3 instead of an invalid type: option. Thanks to @timpritlove for the PR. Closes #20.

  • Rename calendar :format/:stand_alone typespec and docs from :type to :context.

  • Clarify Unit.display_name/2 vs to_string/2 in docs.

[0.23.0] — April 25th, 2026

Bug Fixes

  • Fix Cldr.Number.to_string/2 for Decimal numbers to produce the correct decimal digits.

  • Fix LOCALIZE_UNSAFE_HTTPS env-var contract — values like "FALSE", "nil", an empty string, or unset all keep TLS verification on; only a truthy value disables it. Thanks to @rubas for the PR. Closes #15.

  • Fix Localize.Locale.load/2 and Localize.Locale.get/3 to honor the :provider option — load/2 no longer calls provider.store/2 with the locale id, and get/3 now loads through the same provider it reads from. Thanks to @rubas for the PR. Closes #16.

  • Localize.Locale.get/3 now honors the :fallback option by walking the CLDR parent locale chain when a key is missing in the requested locale. Fallback is handled in Localize.Locale so provider modules stay focused on store-and-fetch semantics. Thanks to @rubas for the PR. Closes #17.

  • Public formatters (Localize.Date, Localize.Time, Localize.DateTime, Localize.DateTime.Relative, Localize.Interval, Localize.List, Localize.Calendar) now accept raw parsed Localize.LanguageTag structs whose :cldr_locale_id is not yet populated. The seven per-module locale resolvers collapse to one shared Localize.Locale.cldr_locale_id_from/1. Thanks to @rubas for the PR. Closes #18.

  • Fix Localize.available_locale_id?/1, Localize.validate_calendar/1, and Localize.validate_number_system/1 to never intern caller-supplied strings as new atoms. Lookups now use compile-time string→atom maps for O(1) safe membership. Thanks to @rubas for the PR. Closes #19.

  • Localize.supported_locales/0 now lazily resolves config :localize, supported_locales: [...] from the application environment when the :persistent_term cache has not yet been populated, instead of falling back to the full CLDR locale list. The cache is populated on application startup, but callers that run before the application has started — notably compile-time macro expansion in dependent applications like localize_web's ~q sigil — previously saw the full CLDR list during partial recompiles. This caused Localize.validate_locale/1 to best-match against all CLDR locales rather than the configured subset, producing incorrect cldr_locale_id resolutions.

[0.22.0] — April 22nd, 2026

Bug Fixes

  • Fix Cldr.Number.to_string/2 for Decimal numbers to produce the correct decimal digits.

[0.21.0] — April 22nd, 2026

Bug Fixes

  • Fix normalizing CLDR locale names to our standard atom format in Localize.validate_calendar/1.

  • Localize.Calendar.iso_day_of_week/1 no longer crashes with MatchError on non-ISO calendars. The generic branch destructured calendar.day_of_week/4 as a 2-tuple but the Calendar behaviour returns {day, first, last}.

  • Localize.Time.to_string/2 with a partial time and a standard format atom (:short/:medium/:long/:full) now derives a CLDR skeleton from the fields actually present (:h, :hm, :ms) instead of returning DateTimeUnresolvedFormatError.

  • Localize.DateTime.to_string/2 no longer silently drops the hour when given a partial datetime such as %{year: _, month: _, day: _, hour: _} without :minute. Partial datetimes render via a split date + time path composed with the locale's datetime wrapper.

  • Localize.DateTime.to_string/2 with hour + minute (no second) under :medium no longer emits a stray trailing : before the AM/PM marker — the partial path derives the :hm skeleton instead of using the full h:mm:ss a pattern with an empty seconds slot.

  • The datetime formatter's AM/PM handler now accepts any map with :hour, not just maps that also have :minute.

  • Localize.Number.to_string/2 now produces identical output for equivalent Decimal and float values. Previously Decimal.new("1234.56") rendered as "1,234.560" under the standard pattern because Decimal.round/3 returns a result padded to the requested scale; the formatter now normalizes after rounding so only the digits actually needed are emitted. Currency and other formats with a mandatory minimum scale still pad correctly via adjust_trailing_zeros/2.

[0.20.0] — April 22nd, 2026

Bug Fixes

  • Fixes mapping CLDR calendar types to the implementation module name.

[0.19.0] — April 19th, 2026

Bug Fixes

  • Restored the support of RBNF locales in Localize.Number.to_string/2. They are implemented in Localize.Number.Rbnf.to_string/1 but the delegation was lost on the ex_cldr transition. Thanks to @tangulip for the report. Closes #11.

[0.18.0] — April 18th, 2026

Breaking Change

  • MF2 highlighter token class atoms renamed to match the tree-sitter capture taxonomy used by mf2_wasm_editor, so one stylesheet now styles both server-rendered HTML and the browser editor.

  • Localize.Message.to_html/2 now emits the new canonical class names with _ converted to - on output (.mf2-variable, .mf2-punctuation-bracket, .mf2-string-escape, .mf2-constant-builtin, etc.).

  • Localize.Message.to_ansi/2 default palette keys renamed to the new atoms.

Removed

  • The mf2_theme_css/ directory and scripts/generate_mf2_themes.exs generator. Themes now live canonically in mf2_wasm_editor.

Bug Fixes

  • Localize.Gettext.Interpolation.runtime_interpolate/2 no longer raises Localize.ParseError when a translated string is not valid MF2. It now returns the message unchanged and logs a warning, matching gettext's own "fall back to the msgid" behaviour for missing translations. Dev-facing UI copy that happens to contain MF2-like syntax (e.g. {{…}} or .match) no longer crashes callers.

[0.17.0] — April 17th, 2026

Added

[0.16.0] — April 17th, 2026

Bug Fixes

  • Fix locale download infinite recursion loop. Thanks to @woylie for the report. Closes #10.

[0.15.0] — April 17th, 2026

Added

Bug Fixes

  • Fix the exception and message when formatting a number and specifying a number system that is not valid for the given locale.

[0.14.0] — April 16th, 2026

Breaking Change

  • Remove @derive for Jason since Jason is no longer configured or used anywhere in the application.

Bug Fixes

  • Fix locale downloader to ensure it only uses the :cldr_locale_id field to construct the download URL.

[0.13.0] — April 15th, 2026

Bug Fixes

  • Localize.Interval.to_string/3 now correctly formats datetime intervals — matching ex_cldr_dates_times behaviour. Previously any interval between two datetime values was rendered as a date-only range, discarding the time portion. Now same-day intervals render as "Apr 8, 2026, 12:00 PM – 2:00 PM" (date once, time range) and different-day intervals render as "Apr 15, 2026, 12:49 AM – Apr 16, 2026, 1:49 AM" (full datetime on both sides). Time-only intervals (Time values on both sides) use the locale's time-interval patterns.

[0.12.0] — April 15th, 2026

Bug Fixes

  • Chinese collation tailorings (zh-u-co-pinyin, zh-u-co-stroke, zh-u-co-zhuyin) now produce correct locale-specific ordering for Han characters. .

  • Han radical-stroke ordering (UAX #38) under -u-co-unihan now applies correctly. The Localize.Collation.Han module was previously orphaned — its data was never loaded in consumer apps and the sort path never consulted it. Radical data is now pre-generated in the build pipeline and shipped in priv/localize/collation_table.etf; the sort path invokes Han.collation_elements/1 for CJK codepoints when the :han_ordering option is :radical_stroke (set automatically for the -u-co-unihan collation type).

Added

  • Localize.Collation.Options.han_ordering option — :implicit (default, UCA codepoint-based) or :radical_stroke (UAX #38). Automatically set to :radical_stroke for -u-co-unihan locales.

  • Persistent-term cache for parsed tailorings. First call to Tailoring.get_tailoring/2 parses the rule string (~70 ms for zh-pinyin); subsequent calls read from persistent_term in microseconds.

  • Differential tests for zh-u-co-pinyin, zh-u-co-stroke, zh-u-co-zhuyin, and ja-u-co-unihan that assert output differs from root codepoint order for specific character pairs — guards against silent regressions.

Changed

[0.11.0] — April 14th, 2026

Added

[0.10.0] — April 14th, 2026

Changed

  • Mix tasks now only do Mix.Task.run("app.config") followed by Application.ensure_all_started(:localize), avoiding starting any consumer application. Thanks to @lostkobrakai for the report. Closes #7,

[0.9.0] — April 14th, 2026

Changed

[0.8.0] — April 14th, 2026

Added

[0.7.0] — April 14th, 2026

Changed

  • Territory subdivision functions are now in the Localize.Territory.Subdivision module. Some functions have been renamed, see Localize.Territory.Subdivision. The translate functions have been removed.

[0.6.0] — April 13th, 2026

Added

  • Public function wrappers in Localize.Unit.Math for all dimensionless functions: sin/1, cos/1, tan/1, asin/1, acos/1, atan/1, sinh/1, cosh/1, tanh/1, asinh/1, acosh/1, atanh/1, exp/1, ln/1, log/1, log2/1. Previously these were only accessible via apply_dimensionless/2.

Bug Fixes

  • apply_dimensionless/2 now validates that the unit is actually dimensionless before computing. Previously sin(1 meter) would silently return a result; it now returns {:error, "sin requires a dimensionless value, got unit with base: meter"}. Units must reduce to revolution (angles) or part (ratios) to be accepted.

[0.5.0] — April 13th, 2026

Added

  • :special conversion support in CustomRegistry. Custom units can now be registered with factor: :special plus :forward and :inverse {module, function} tuples for nonlinear conversions. This enables logarithmic scales (decibels), temperature functions, density hydrometers, wire gauges, and other conversions that cannot be expressed as value * factor + offset.

  • Conversion.do_convert/3 now uses a generalised special_unit/1 lookup that checks both CustomRegistry and a compiled @built_in_special map, replacing the previous hardcoded :beaufort pattern match.

[0.4.0] — April 13th, 2026

Bug Fixes

  • Localize.all_locale_ids/1 (:modern, :moderate, :basic) now returns the correct expanded list of locales. Thanks to @cw789 for the report.

[0.3.0] — April 13th, 2026

Bug Fixes

  • Load custom units in a single batch to avoid churning :persistent_store

[0.2.0] — April 13th, 2026

Bug Fixes

  • SI prefix parsing for custom units. Custom units can now be prefixed with SI prefixes and power prefixes.

Enhancements

  • Custom unit category validation relaxed from a fixed allowlist to any non-empty string. The faciliates importing a broader range of unit definitions such as those from Gnu units.

[0.1.0] — April 13th, 2026

Initial release.

Highlights

  • Full CLDR v48.2 locale data with lazy runtime loading from ETF files cached in :persistent_term. No compile-time backend configuration required.

  • Number formatting — integers, decimals, percentages, currencies, ranges, and rule-based number formats (RBNF) including Roman numerals and CJK ideographs.

  • Date, time, and datetime formatting using CLDR calendar patterns with :short, :medium, :long, and :full styles, custom skeleton patterns, and interval formatting.

  • Unit formatting with plural-aware patterns, SI/binary prefixes, compound units, measurement system conversion, custom unit registration, and Localize.Unit.Operators for natural arithmetic (km + m).

  • List formatting with locale-appropriate conjunctions, disjunctions, and unit list styles. Per-element formatting via Localize.Chars.

  • ICU MessageFormat 2 (MF2) parser and interpreter with custom function registry, offset selection, JSON interchange, and bidirectional text support.

  • Gettext integration — Localize.Gettext.Interpolation provides MF2-based interpolation for Gettext backends.

  • Localize.Chars protocol — polymorphic locale-aware formatting with built-in implementations for 14 types and Any fallback to Kernel.to_string/1.

  • Currency metadata, ISO 4217 validation, custom currency registration (private-use and extended codes), and territory-to-currency mapping.

  • Display names for territories, languages, scripts, calendars, and full locale display names per the CLDR algorithm.

  • Unicode Collation Algorithm (UCA) with CLDR locale-specific tailoring for 97 languages, including digraph expansion and script reordering.

  • BCP 47 / RFC 5646 language tag parser with full Unicode extension support (-u-, -t-), locale distance matching, and parent chain resolution.

  • On-disk locale cache with HTTPS download provider, version-based staleness detection, and mix localize.download_locales for build-time cache population.

  • Optional NIF backend for faster Unicode normalisation and collation sort-key generation.

  • Calendar data for all CLDR calendar systems including Buddhist, Hebrew, Islamic (5 variants), ROC, Indian, Persian, Coptic, Ethiopic, Chinese, Japanese, and Dangi.

  • All public API functions return a standardized {:error, exception} (except bang variants). The exception is a standard Elixir exception struct populated with semantic information about the error. The error message can be returned by Exception.message(exception). The exception messages are all Gettext messages using the MF2 format and can be localized.

See the README for full documentation, configuration options, and usage examples.