API reference

Library API

These pages are generated from the library’s own doc comments: every declaration, with its signature and nothing else. The written library section is the other half — what each module…

These pages are generated from the library’s own doc comments: every declaration, with its signature and nothing else. The written library section is the other half — what each module is for, why its pieces are shaped as they are, and worked examples you can run. Start there to learn a module; come here when you know what you want and need its exact signature.

Modules

Module	Summary
`sysl`	The core: what every program has without importing anything.
`sysl.args`	How a program’s arguments become a `[]string`, written here because every line of it is ordinary sysl.
`sysl.buf`	The growable sequence and the sink built on it.
`sysl.checksum`	Checksums that detect accidental corruption and nothing else.
`sysl.container`	Five containers, each with a shape a slice and a `Buf` cannot give you.
`sysl.container.ring`	A queue of a fixed capacity, laid over storage the caller supplies, cheap to take from at either end and needing no allocator at all.
`sysl.crypto`	Cryptographic hashing: the SHA-2 family, SHA-1 and MD5, HMAC over any of them, and PBKDF2.
`sysl.dma`	Memory a device can reach by address, and the handover that makes it safe to share with one.
`sysl.encoding`	Bytes as text and text as bytes: hexadecimal, base64, UUIDs, and fixed-width integers at either byte order, read, written in place or appended.
`sysl.encoding.json`	JSON, read and written: a document parsed into a value tree that owns itself, and a value tree written back out compactly or for a person to read.
`sysl.env`	Reading the environment a program was started with.
`sysl.env.hosted`
`sysl.env.sys`
`sysl.fmt`	What an `f"…"` hole’s computed width or precision comes to — `${x}%.${n}f`, `${s}%${w}s` — and what an integer under a specifier renders as — `${n}%08x`.
`sysl.fs`	What is at the end of a path: reading and writing whole files, metadata, directories, links, and the errors any of it can answer with.
`sysl.fs.errtext`
`sysl.fs.hosted`
`sysl.fs.sys`
`sysl.harness`	A test framework that runs on the target.
`sysl.io`	The byte surface a program reads through, and the line cursor over it.
`sysl.io.hosted`
`sysl.io.sys`
`sysl.log`	Structured logging: a level, a message, a few named fields, and somewhere for them to go.
`sysl.math`	Mathematics on the numeric types: the float functions, the integer ones, and the traits that let a program write both at whichever width it is already using.
`sysl.math.bigint`	Integers with no width: sign and magnitude, the magnitude a run of 32-bit limbs.
`sysl.math.complex`	Complex numbers, at whichever floating-point width the program is already using.
`sysl.math.decimal`	Exact decimal arithmetic: an integer coefficient and a scale, so `0.1 + 0.2` is `0.3`.
`sysl.math.rational`	Exact fractions: a numerator and a denominator, both `BigInt`s, so a third is a third.
`sysl.net`	Blocking sockets – a TCP stream, a UDP socket – and the names a host resolves to.
`sysl.net.hosted`
`sysl.net.sys`
`sysl.path`	Path handling that is decided by the string alone.
`sysl.posix.rand`	A seed taken from the host, for a program that wants a different sequence on every run.
`sysl.posix.threads`	`sysl.threads` under the name it had when its threads were pthreads, kept for the programs that import it.
`sysl.posix.time`	Reading the two clocks the host keeps, which is the one thing `sysl.time` deliberately cannot do.
`sysl.posix.tty`	Whether escapes should be written at all.
`sysl.process`	Starting another program and waiting for what it does.
`sysl.process.hosted`
`sysl.process.sys`
`sysl.rand`	Pseudo-random numbers: a named, seedable, reproducible generator, and the distributions that are easy to get wrong.
`sysl.regex`	Matching text against a pattern: compile one, then find, replace or split with it.
`sysl.seq`	What a sequence of values can be asked, in one trait, so that a slice and a `Buf` answer the same names.
`sysl.signal`	Signals as flags: a program asks to be told that one arrived, and asks again later whether it has.
`sysl.signal.hosted`
`sysl.signal.sys`
`sysl.slices`	Operations over a built-in slice, and the pointer a C binding needs to hand one across.
`sysl.softfloat`
`sysl.softfloat.binary64`
`sysl.softint`
`sysl.softint.aeabi`
`sysl.sync`	What two threads may touch at once: `Atomic[T]`, `SpinLock`, and the five memory orderings.
`sysl.sys`	The platform seam: everything the library asks of what it is hosted on, and nothing else.
`sysl.term`	What a terminal understands: the escape sequences that colour text, emphasise it, and move the cursor about.
`sysl.term.edit`	Reading a line from a terminal that will not do it for you.
`sysl.testing`	What a test may say about itself while it runs, beyond passing or failing.
`sysl.text`	The whole text surface: what a `string` is made of, and every operation over one.
`sysl.threads`	Threads of execution, and the two things a program does with one: start it, and wait for it – with the lock, the condition variable and the channel threads share things through.
`sysl.threads.hosted`
`sysl.threads.sys`
`sysl.time`	Points on the timeline, lengths of it, and the calendar that turns one into a date.
`sysl.time.tzif`	Reading a zone out of the bytes of a TZif file (RFC 8536), which is what the IANA time zone database is distributed as.
`sysl.tty`	A terminal’s mode: line by line or a keystroke at a time, echoing or not, and putting back what was there.
`sysl.tty.hosted`
`sysl.tty.sys`
`sysl.unicode`	What the Unicode Character Database says about a character, and the operations over text that only that database can answer.