Sifr Standard Library: Built-in Modules Overview Guide

Sifr ships a comprehensive standard library under the sifr.* namespace. Every module is designed with Rust-backed safety guarantees — predictable ownership, explicit error types, and no hidden global mutation. Because Sifr compiles to Rust rather than running on the CPython interpreter, the standard library is its own surface; it is not a thin wrapper around CPython’s built-in modules. For a compact inventory of every module currently shipped in stdlib/sifr, see the Module Index.

How to Import

Use from sifr.<module> import <symbol> for every standard library import:

from sifr.math import sqrt
from sifr.json import loads, dumps
from sifr.encoding import decode, encode
from sifr.unicode import normalize
from sifr.i18n import LocaleId
from sifr.task import TaskGroup
from sifr.net import connect_tcp

Bare CPython module names are not supported. Importing math, json, os, collections, codecs, unicodedata, locale, or any other CPython stdlib name directly triggers error SIFR-IMPORT-0008 and the compiler suggests the correct sifr.* replacement.

# ❌ Rejected — raises SIFR-IMPORT-0008
from math import sqrt
import json

# ✅ Correct
from sifr.math import sqrt
from sifr.json import loads

import sifr.math (module-object form) is also unsupported in the current release. Always import the specific symbols you need using from sifr.<module> import <symbol>.

If a real user-defined or third-party top-level module named math, json, or similar exists in your project, the normal top-level resolution imports it without a diagnostic. The SIFR-IMPORT-0008 error only fires when no real top-level module matches the bare name.

Available Modules

Math, Data, and Serialization

Module	Description
`sifr.math`	Mathematical functions: `sqrt`, `floor`, `ceil`, `log`, trigonometric helpers, and numeric constants.
`sifr.json`	JSON serialization and deserialization. `loads` returns a typed `JsonValue`; `dumps` serializes Sifr values to JSON strings. Malformed input raises `JSONDecodeError`.
`sifr.re`	Regular expression matching and substitution with Unicode-aware patterns.
`sifr.datetime`	Date and time values, durations, timezone-aware timestamps, and formatting.
`sifr.random`	Cryptographically seeded random number generation.
`sifr.hashlib`	Hash functions: SHA-256, SHA-512, MD5 (legacy), BLAKE3, and HMAC construction.
`sifr.uuid`	UUID generation (`uuid4`) and parsing for v4 and v5 identifiers.

Collections

Module	Description
`sifr.collections`	`Counter`, `deque`, `defaultdict`, and set helpers (`set_from_list`, `set_union`, `set_intersection`). Safe indexing returns `Option` instead of raising `KeyError` or `IndexError`.

Filesystem and Environment

Module	Description
`sifr.io`	`open_text` for text files with a required explicit encoding, and binary file I/O. Text-mode `open()` without `encoding=` is unsupported (`SIFR-IO-0801`).
`sifr.pathlib`	`Path` construction, joining, extension manipulation, existence checks, and directory traversal.
`sifr.os`	File and directory operations: `remove_file`, `rename`, `mkdir`, `listdir`, and stat helpers.
`sifr.env`	Read and write process environment variables as explicit typed values.
`sifr.sys`	Process arguments (`argv`), exit helpers, and platform query values.

Text, Encoding, and Internationalization

Module	Description
`sifr.encoding`	Byte/text boundary conversions: `encode`, `decode`, codec descriptors (`ascii()`, `latin1()`), error handlers, and typed `DecodeError` / `EncodeError`.
`sifr.unicode`	Unicode 17.0.0 data: `normalize` (NFC/NFD/NFKC/NFKD), `name`, `category`, `graphemes`, `words`, and scalar properties.
`sifr.i18n`	Locale-aware formatting: `LocaleId`, `NumberFormatter`, `PluralRules`, `bundle_from_mo_bytes`, and `translator` with explicit fallback chains.

Concurrency and Parallelism

Concurrency has its own docs section. Start with the Concurrency Overview, then use the Concurrency API for module reference.

Module	Description
`sifr.task`	Structured task management: `TaskGroup`, `TaskHandle[T, E]`, scoped `spawn`, `timeout`, `deadline`, `gather`, and `select`.
`sifr.sync`	Same-process synchronization: `Shared[T]`, `channel`, `bounded_channel`, `Lock`, `RwLock`, `Semaphore`, and `Notify`.
`sifr.parallel`	CPU-parallel map over owned data: `map`, `try_map`, `Pool`, and `PoolConfig`.
`sifr.runtime`	Structured runtime diagnostics: `DiagnosticEvent`, `DiagnosticLevel`, `emit_diagnostic`, and `DiagnosticError`.
`sifr.resource`	Deterministic cleanup helpers: `nullcontext` and `NullContext[T]`.
`sifr.ipc`	Typed IPC substrate for Sifr-native process workers: `SchemaId`, `FrameKind`, `BackpressurePolicy`, and `IpcError`.

Networking

Module	Description
`sifr.net`	Async TCP client and server primitives: `connect_tcp` and `listen_tcp`.
`sifr.http`	HTTP protocol substrate: methods, status codes, `HeaderMap`, `RequestHead`, `ResponseHead`, `BodyStream`, and cookie parsing.
`sifr.tls`	Rustls-backed TLS client configurations and encrypted streams over `sifr.net`.
`sifr.url`	Typed URL parsing, query-string manipulation, and percent-encoding helpers.

Process, Signal, and Time

Module	Description
`sifr.process`	Subprocess management: `run`, `spawn`, `output`, `output_text`, shell helpers, and async variants. Handles are owned resources with typed `ProcessError`.
`sifr.signal`	Structured shutdown signals: `ctrl_c`, `shutdown_stream`, `SIGINT`, `SIGTERM`, and `strsignal`.
`sifr.time`	Monotonic and wall-clock time, sleep, and interval helpers.
`sifr.logging`	Structured log emission with levels (`DEBUG`, `INFO`, `WARN`, `ERROR`) and typed diagnostic events.

What Sifr Does Not Expose

Several CPython-shaped names are intentionally absent because they rely on global mutable state or interpreter-specific behavior that conflicts with Sifr’s safety model:

asyncio event-loop objects and loop-policy mutation
threading.Lock, queue.Queue, and multiprocessing.*
codecs.register, locale.setlocale, and gettext.install
signal.signal and set_wakeup_fd for arbitrary handler registration

Each of these has a typed, ownership-safe equivalent in the sifr.* namespace. See the individual module pages for details.

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Sifr Standard Library: Built-in Modules Overview Guide

How to Import

Available Modules

What Sifr Does Not Expose

​How to Import

​Available Modules

​What Sifr Does Not Expose

How to Import

Available Modules

What Sifr Does Not Expose