runner

type struct Name { ... }
type enum Name { ... }
type trait Name { ... }
type union Name { ... }

Begins a type declaration; the keyword that follows says which kind. On its own, type Name = Existing; declares an alias.

type struct Name {
    field: Type;
    method(&this) -> Ret { ... }
}

A value type with named fields and optional methods. Structs live on the stack and are passed by value. Fields are public by default and may carry = default values; methods take their receiver as &this, mut &this, or this.

RunOptions.filter: String

Substring filter: empty means "match everything".

type struct String<A = GlobalAlloc> {
    buffer: RawBuffer<u8, A>;
    length: u64;
}

String: owned, heap-allocated, length-typed UTF-8.

primitive boolean

true / false. Not interchangeable with integers. 1 byte.

RunOptions.format_explicit: boolean

True if the user explicitly passed --format=.... Used to decide whether env-var or cryoconfig defaults can override.

RunOptions.color_active: boolean

Resolved once at the start of run_all: did color plus the TTY check land on "emit escapes". Reporters consult this flag rather than re-evaluating the policy on each test.

RunOptions.timeout_secs: u32

Per-test wall-clock limit in seconds. The child arms alarm() with this value before running; 0 disables the watchdog.

primitive u32

32-bit unsigned integer.

RunOptions.timeout_explicit: boolean

True if --timeout= was passed explicitly (suppresses the CRYO_TEST_TIMEOUT env default).

RunOptions.jobs: u32

Number of worker threads to drive tests in parallel. 0 means "auto" -> resolved to the online CPU count at the start of run_all. 1 forces the classic sequential path. Each worker still runs every test in its own child process, so parallelism does not weaken crash / should_panic isolation.

RunOptions.jobs_explicit: boolean

True if --jobs=/-j was passed explicitly (suppresses the CRYO_TEST_JOBS env default).

RunOptions.capture: boolean

Capture each test's stdout+stderr into a per-test buffer instead of letting it stream to the terminal. On (the default) the buffer is replayed only for failing tests, so a green parallel run stays clean.

RunOptions.show_output: boolean

Show captured output for *passing* tests too, not just failures. Set by --show-output. No effect when capture is off.

RunOptions.child_idx: i64

Re-exec child selector: >= 0 means "run only descriptors[child_idx] and exit 0/1, no header/loop". Set by the internal --test-runner-child=<n> flag the Windows runner passes when it CreateProcess-re-execs the test binary once per test (Windows has no fork, so each test runs in a fresh process selected by index).

primitive i64

64-bit signed integer.

static name(param: Type) -> Ret { ... }

A method that belongs to the type rather than an instance, called as Type::name(..). For structs, static new(..) returning a struct literal is the idiomatic constructor.

type enum Name {
    Unit,
    Payload(T),
    Named { x: i32 },
}

An algebraic data type. Variants may be bare or carry a tuple or struct payload, and a match on an enum must cover every variant. Name::Variant names a variant; methods are added with implement enum Name { ... }.

TestOutcome::Pass

Test passed: child exited 0 (or signaled, when should_panic is set).

TestOutcome::Fail(i32, i32, boolean)

Test ran but failed: child returned Err (exit != 0) or panicked unexpectedly. Exit-code and signal carried through so the summary can show the cause.

primitive i32

32-bit signed integer.

TestOutcome::Skipped

Test was marked ![ignore] and the user did not pass --ignored.

TestOutcome::DidNotPanic

![should_panic] was set but the test exited 0; that is itself a failure.

TestOutcome::Timeout(u32)

The test exceeded the per-test wall-clock limit and was killed by the alarm() watchdog (SIGALRM). Always a failure, even under ![should_panic]. Carries the configured limit in seconds.

TestOutcome::RunnerError(i32)

Couldn't fork() or waitpid(); runner-internal error.

const NAME: Type = value;

At module level, a true compile-time constant, conventionally SCREAMING_SNAKE_CASE. (mut at module level declares mutable global state instead.)

primitive string

NUL-terminated raw string (u8*), matching the C ABI. Length-typed text is Str / String.

primitive u64

64-bit unsigned integer.

import a::b;
import a::b::{ X, Y };
import a::b as c;
import a::b::*;

Brings a module, or selected items from it, into scope. One path per declaration: use the brace form for several items, as to alias, and * for everything public (prefer the brace form; wildcards invite name collisions).

namespace std;

std: the Cryo standard library.

namespace std::test;

test: Cryo's built-in unit-test framework.

namespace std::test::runner;

Test runner: fork-per-test driver.

RunOptions.filter: String

Substring filter: empty means "match everything".

RunOptions.timeout_secs: u32

Per-test wall-clock limit in seconds. The child arms alarm() with this value before running; 0 disables the watchdog.

RunOptions.jobs: u32

Number of worker threads to drive tests in parallel. 0 means "auto" -> resolved to the online CPU count at the start of run_all. 1 forces the classic sequential path. Each worker still runs every test in its own child process, so parallelism does not weaken crash / should_panic isolation.

RunOptions.capture: boolean

Capture each test's stdout+stderr into a per-test buffer instead of letting it stream to the terminal. On (the default) the buffer is replayed only for failing tests, so a green parallel run stays clean.

RunOptions.show_output: boolean

Show captured output for *passing* tests too, not just failures. Set by --show-output. No effect when capture is off.

RunOptions.format_explicit: boolean

True if the user explicitly passed --format=.... Used to decide whether env-var or cryoconfig defaults can override.

RunOptions.color_active: boolean

Resolved once at the start of run_all: did color plus the TTY check land on "emit escapes". Reporters consult this flag rather than re-evaluating the policy on each test.

function run_all(argc: i32, argv: u8**, descriptors: TestDescriptor*, count: u64) -> i32

Run every test in descriptors that matches argc/argv filtering, printing a line per test. Returns 0 if every selected test passed; 1 otherwise.

RunOptions.timeout_explicit: boolean

True if --timeout= was passed explicitly (suppresses the CRYO_TEST_TIMEOUT env default).

RunOptions.jobs_explicit: boolean

True if --jobs=/-j was passed explicitly (suppresses the CRYO_TEST_JOBS env default).

RunOptions.child_idx: i64

Re-exec child selector: >= 0 means "run only descriptors[child_idx] and exit 0/1, no header/loop". Set by the internal --test-runner-child=<n> flag the Windows runner passes when it CreateProcess-re-execs the test binary once per test (Windows has no fork, so each test runs in a fresh process selected by index).

TestOutcome::Fail(i32, i32, boolean)

Test ran but failed: child returned Err (exit != 0) or panicked unexpectedly. Exit-code and signal carried through so the summary can show the cause.

TestOutcome::DidNotPanic

![should_panic] was set but the test exited 0; that is itself a failure.

TestOutcome::Timeout(u32)

The test exceeded the per-test wall-clock limit and was killed by the alarm() watchdog (SIGALRM). Always a failure, even under ![should_panic]. Carries the configured limit in seconds.

TestOutcome::RunnerError(i32)

Couldn't fork() or waitpid(); runner-internal error.

TestOutcome::Pass

Test passed: child exited 0 (or signaled, when should_panic is set).

TestOutcome::Skipped

Test was marked ![ignore] and the user did not pass --ignored.

implement struct Name { ... }
implement trait Trait for Type { ... }
implement u64 { ... }

Adds methods to a type outside its declaration. implement struct T (or enum, or a bare primitive) opens an inherent block; implement trait Tr for T supplies a trait's methods for one type. Resolution is at compile time - no dynamic dispatch.

implement trait Trait for Type { ... }

Introduces a trait implementation: the block supplies, for one concrete type, the method bodies the trait requires.

type trait Drop {
    drop(mut &this) -> void;
}

Drop: explicit destructor.

implement trait Trait for Type { ... }

Names the type a trait implementation is for. The block that follows supplies the bodies the trait requires.

function name<T>(param: Type) -> Ret { ... }

Declares a function. Parameters are written name: Type and are never inferred; the return type follows -> and defaults to void. Declaration order does not matter: every signature is collected before any body is checked, so functions may call each other freely and recurse.

function run_all(argc: i32, argv: u8**, descriptors: TestDescriptor*, count: u64) -> i32

Run every test in descriptors that matches argc/argv filtering, printing a line per test. Returns 0 if every selected test passed; 1 otherwise.

primitive u8

8-bit unsigned integer.

type struct TestDescriptor {
    name: Str;
    ignored: boolean;
    should_panic: boolean;
}

One discovered ![test] function plus its sibling-directive flags.