README

Phuture Continuum

A forward-compatibility layer bringing tomorrow’s PHP features to today’s runtimes.

Introduction

Continuum bridges the gap between PHP versions by extending Symfony Polyfill with additional methods, constants, and stubs. Built on Symfony's solid foundation, Continuum provides extra polyfills and graceful fallbacks—enabling you to write forward-compatible code that works consistently across different PHP runtimes.

Features

This package polyfills most common PHP functions from PHP 8.1 to 8.6, designed to be used on PHP 8.0 or later.

This package also provides polyfills for some PHP extensions, allowing better portability across different PHP runtimes.

What's Not Covered

The entries marked ❇️ Partial or ⚠️ Partial in the tables above have meaningful gaps. This section documents exactly what each one omits or cannot replicate.

Partial Polyfills

fsync() / fdatasync() (PHP 8.1)

• Both fall back to fflush(), plus posix_fsync() when the posix extension is loaded.
• There is no guarantee of actual disk-level synchronization on systems without the POSIX extension.
• The return value is always true, even when the underlying OS sync did not occur.

curl_upkeep() (PHP 8.2)

• Only sets CURLOPT_FORBID_REUSE = false and CURLOPT_FRESH_CONNECT = false.
• Does not perform real HTTP/2 connection maintenance (window-size updates, PING frames, or keep-alive signalling).
• Full behaviour requires PHP 8.2+ with libcurl ≥ 7.62.0.

Time\Duration (PHP 8.6)

1. readonly is not enforced on PHP 8.0 — writes to $seconds, $nanoseconds or $negative succeed silently instead of raising Error, and can desynchronise the internal comparison fields, affecting only the raw < / > operators. Enforced natively on 8.1+.
2. Two private implementation properties emulate the native comparison handler. They are hidden from var_dump(), print_r(), json_encode(), foreach and get_object_vars(), but are visible to var_export(), serialize(), (array) casts and Reflection.
3. The class is user-defined, not internal: ReflectionClass::isInternal() is false and it is not a readonly class, so a dynamic-property write emits a deprecation on PHP 8.2+ instead of raising Error, and unserialize() can construct instances bypassing the private constructor.
4. Internal functions cannot accept a Duration. The RFC's motivating example sleep(\Time\Duration::fromMilliseconds(500)) depends on native signature changes that userland cannot make.
5. Comparing a Duration against a non-Duration value follows generic userland object-comparison rules, which may differ from the native comparison handler.
6. Duration::compare(...) first-class-callable syntax requires PHP 8.1; on PHP 8.0 use usort($durations, [\Time\Duration::class, 'compare']).
7. On 32-bit builds $seconds is capped at 2_147_483_647 (~68 years) instead of 9_223_372_035, and divideBy() routes through bcmath.
8. Error parity is best-effort: for cases the RFC does not pin — exact ValueError message texts and the exception type for a malformed ISO-8601 string — the polyfill follows php-src conventions but may differ until php-src PR #23073 is merged.

Partial Extensions

ext-mbstring

• The only functions with no polyfill are the stateful regex-search family: mb_ereg_search(), mb_ereg_search_init(), mb_ereg_search_pos(), mb_ereg_search_regs(), mb_ereg_search_getpos(), mb_ereg_search_getregs(), and mb_ereg_search_setpos().
• mb_convert_kana() supports only the R, r, N, n, K, k, V, A, a conversion modes.

ext-apcu

• In-memory, non-persistent cache: data is lost between requests.
• Scoped to a single process; entries are not shared across PHP-FPM workers.
• No atomic operations beyond basic get/set; no TTL-based eviction or shared-memory sizing.

ext-intl

• Collator: simplified sorting - does not implement the full Unicode Collation Algorithm.
• NumberFormatter: advanced formatting features (currency symbol overrides, padding, significant digits) are missing.
• Locale: operations are simplified; no full CLDR data lookup.
• No direct access to ICU binary data; limited to the subset bundled with Symfony.

ext-zip

• ZipArchive::getArchiveFlag() - always returns 0; archive-level flags are a libzip internal concept not accessible through userland php.
• ZipArchive::setArchiveFlag() - always returns false.
• ZipArchive::registerProgressCallback() - always returns false.
• ZipArchive::registerCancelCallback() - always returns false.
• Procedural zip_entry_open() only accepts modes r and rb; write-mode entry access is not supported.
• Multi-disk ZIP archives are not supported.
• Writing with compression methods CM_LZMA, CM_LZMA2, and CM_XZ is not supported.

Installation

composer require phuture/continuum

Contributing

Thank you for considering contributing to this project! You can read the Contribution Guide and our Developer Workflow Guide.

Code of Conduct

This project follows a Code of Conduct that all community members and contributors are expected to adhere to our Contributor Code of Conduct.

License

This project is open-source and available under the MIT License.