Built-in Functions

Asserts two values are equal by canonical rendering. Success payloads compare by value; Errors remain visible as Error(message). On mismatch, marks the enclosing test failed and prints a diagnostic; execution continues.

expectAll

Signature: expectAll(conditions: List<bool>) -> Unit

Runs every boolean in a list literal as an independent soft assertion. All conditions run even when an earlier one fails.

expectFalse

Signature: expectFalse(actual: bool) -> Unit

Asserts that a boolean expression is false.

expectTrue

Signature: expectTrue(actual: bool) -> Unit

Asserts that a boolean expression is true.

fiberDone

Signature: fiberDone(fiber: Fiber<t0>) -> int

Returns 1 if the given fiber has finished, 0 otherwise.

fiber_yield

Signature: fiber_yield(value: int) -> int

Yields control to the fiber scheduler and returns its integer value.

filter

Signature: filter(iterator: Iterator<t0>, predicate: (t0) -> bool) -> Iterator<t0>

Filters elements in an iterator based on a predicate function.

fold

Signature: fold(iterator: Iterator<t0>, initial: t1, fn: (t1, t0) -> t1) -> t1

Reduces an iterator to a single value by repeatedly applying a function.

forEach

Signature: forEach(iterator: Iterator<t0>, function: (t0) -> Unit) -> Unit

Applies a function to each element in an iterator.

forEachList

Signature: forEachList(list: List<t0>, function: (t0) -> Unit) -> Unit

Applies function to every list element in index order.

fromCodePoint

Signature: fromCodePoint(codePoint: int) -> Result<string, Error>

Returns the single-character string for a nonzero Unicode scalar, or an error for U+0000 and non-scalars.

httpCloseClient

Signature: httpCloseClient(clientID: int) -> int

Closes the HTTP client and returns the runtime status.

httpCreateClient

Signature: httpCreateClient(base_url: string, timeout: int) -> int

Creates an HTTP client and returns its handle, or a negative runtime error.

httpCreateServer

Signature: httpCreateServer(port: int, address: string) -> int

Creates an HTTP server bound to the specified port and address.

httpDelete

Signature: httpDelete(clientID: int, path: string, headers: string) -> int

Makes an HTTP DELETE request and returns its status code, or a negative transport error.

httpGet

Signature: httpGet(clientID: int, path: string, headers: string) -> int

Makes an HTTP GET request and returns its status code, or a negative transport error.

httpGetResponse

Signature: httpGetResponse(clientID: int, path: string, headers: string) -> Result<int, Error>

Sends an HTTP GET request and returns a response handle for inspecting the status, headers, and body.

httpListen

Signature: httpListen(serverID: int, handler: (string, string, string, string) -> HttpResponse) -> int

Starts the HTTP server with a request handler and returns 0 or a negative runtime error.

httpPost

Signature: httpPost(clientID: int, path: string, body: string, headers: string) -> int

Makes an HTTP POST request and returns its status code, or a negative transport error.

httpPut

Signature: httpPut(clientID: int, path: string, body: string, headers: string) -> int

Makes an HTTP PUT request and returns its status code, or a negative transport error.

httpResponseBody

Signature: httpResponseBody(responseID: int) -> Result<string, Error>

Returns the body of a response handle as a string.

httpResponseFree

Signature: httpResponseFree(responseID: int) -> Result<int, Error>

Releases a response handle; an invalid handle or double free returns Error.

httpResponseHeader

Signature: httpResponseHeader(responseID: int, name: string) -> Result<string, Error>

Returns the value of the named header from a response handle.

httpResponseStatus

Signature: httpResponseStatus(responseID: int) -> int

Returns the HTTP status code of a response handle.

httpStopServer

Signature: httpStopServer(serverID: int) -> int

Stops the HTTP server and returns the runtime status.

indexOf

Signature: indexOf(s: string, needle: string) -> Result<int, Error>

Returns the byte index of needle's first occurrence, or Error with 'indexOf: substring not found'.

input

Signature: input() -> string

Reads a string from the user's input.

intDiv

Signature: intDiv(a: int, b: int) -> Result<int, Error>

Truncating integer division. Zero returns Error(division by zero); INT64_MIN / -1 returns Error(integer overflow).

isEmpty

Signature: isEmpty(s: string | List<T> | Map<string, V>) -> bool

True if a string has zero bytes or a List/Map has zero elements.

join

Signature: join(parts: List<string>, separator: string) -> string

Concatenates parts with separator between each pair.

jsonFree

Signature: jsonFree(document: int) -> Result<int, Error>

Releases a parsed JSON document handle obtained from jsonParse.

jsonGet

Signature: jsonGet(document: int, path: string) -> Result<string, Error>

Returns a JSON scalar at the given path as a string. Arrays, objects, invalid paths, and invalid handles return Error.

jsonLength

Signature: jsonLength(document: int, path: string) -> int

Returns an array length or object member count at the given path, or -1 for an invalid path, handle, or scalar.

jsonParse

Signature: jsonParse(text: string) -> Result<int, Error>

Parses a JSON string and returns an opaque document handle for querying, or an error on malformed input.

length

Signature: length(s: string | List<T> | Map<string, V>) -> int

Returns a string's byte length or a List/Map element count.

lines

Signature: lines(s: string) -> List<string>

Splits on '\n'. A trailing newline does not produce an empty entry.

listAppend

Signature: listAppend(list: List<t0>, value: t0) -> List<t0>

Returns a new list with value at the end. Amortized O(1).

listConcat

Signature: listConcat(left: List<t0>, right: List<t0>) -> List<t0>

Returns left ++ right. Same as left + right.

listContains

Signature: listContains(list: List<t0>, value: t0) -> bool

Linear search. Strings compare by content, scalars by value, and managed handles by identity.

listGet

Signature: listGet(list: List<t0>, index: int) -> Result<t0, Error>

Returns the element at the given index, or an error if the index is out of range.

listLength

Signature: listLength(list: List<t0>) -> int

Returns the number of elements in a list. O(1).

listPrepend

Signature: listPrepend(list: List<t0>, value: t0) -> List<t0>

Returns a new list with value at the front. O(n).

listReverse

Signature: listReverse(list: List<t0>) -> List<t0>

Returns a new list in reverse order.

map

Signature: map(iterator: Iterator<t0>, fn: (t0) -> t1) -> Iterator<t1>

Transforms each element in an iterator using a function, returning a new iterator.

mapContains

Signature: mapContains(map: Map<string, t0>, key: string) -> bool

True iff key is present in map.

mapGet

Signature: mapGet(map: Map<string, t0>, key: string) -> Result<t0, Error>

Returns the value associated with the key, or an error if the key is absent.

mapKeys

Signature: mapKeys(map: Map<string, t0>) -> List<string>

All keys of the map as a list. Order unspecified.

mapLength

Signature: mapLength(map: Map<string, t0>) -> int

Returns the number of entries in a map. O(1).

mapMerge

Signature: mapMerge(left: Map<string, t0>, right: Map<string, t0>) -> Map<string, t0>

Right-biased union. Same as left + right.

mapRemove

Signature: mapRemove(map: Map<string, t0>, key: string) -> Map<string, t0>

Returns a new map without key. No-op if key is absent.

mapSet

Signature: mapSet(map: Map<string, t0>, key: string, value: t0) -> Map<string, t0>

Returns a new map with key bound to value (replaces prior binding).

mapValues

Signature: mapValues(map: Map<string, t0>) -> List<t0>

All values of the map as a list. Order matches mapKeys.

padEnd

Signature: padEnd(s: string, targetLength: int, fill: string) -> Result<string, Error>

Pads s on the right with copies of fill to reach targetLength bytes.

padStart

Signature: padStart(s: string, targetLength: int, fill: string) -> Result<string, Error>

Pads s on the left with copies of fill to reach targetLength bytes.

parseFloat

Signature: parseFloat(s: string) -> Result<float, Error>

Strict finite base-10 floating-point parser. Rejects surrounding whitespace, NaN/infinity spellings, and hexadecimal floats.

parseInt

Signature: parseInt(s: string) -> Result<int, Error>

Strict base-10 signed-int parser. No whitespace tolerance.

print

Writes a supported scalar or Result representation followed by a newline. Unit renders as 0.

random

Signature: random() -> int

A cryptographically-secure uniform random non-negative integer (0 .. 2^63-1), drawn fresh from the OS entropy source. Unseeded and unpredictable.

randomBelow

Signature: randomBelow(n: int) -> Result<int, Error>

A cryptographically-secure uniform random integer in [0, n), unbiased by rejection sampling. Returns Result<int, Error> when n is positive and Error otherwise.

range

Signature: range(start: int, end: int) -> Iterator<int>

Creates an iterator that generates numbers from start to end (exclusive).

readFile

Signature: readFile(filename: string) -> Result<string, Error>

Reads the entire contents of a file as a string.

recv

Signature: recv(channel: Channel<t0>) -> t0

Blocks while the channel is empty, then receives its oldest value.

repeat

Signature: repeat(s: string, n: int) -> Result<string, Error>

Concatenates s with itself n times. A negative n returns Error.

replace

Signature: replace(s: string, needle: string, replacement: string) -> Result<string, Error>

Replaces every occurrence of needle. An empty needle returns Error.

reverse

Signature: reverse(s: string) -> string

Reverses byte order.

send

Signature: send(channel: Channel<t0>, value: t0) -> Unit

Blocks while the channel is full, then sends a value and returns Unit.

sleep

Signature: sleep(milliseconds: int) -> Unit

Pauses execution for the specified number of milliseconds.

spawnProcess

Signature: spawnProcess(command: string, callback: (int, int, string) -> Unit) -> Result<int, Error>

Spawns a process and reports stdout, stderr and exit events through the required callback. Returns a handle for the running process.

split

Signature: split(s: string, separator: string) -> Result<List<string>, Error>

Splits s on separator. An empty separator returns Error.

startsWith

Signature: startsWith(s: string, prefix: string) -> bool

True if s begins with prefix.

substring

Signature: substring(s: string, start: int, end: int) -> Result<string, Error>

Extracts s[start, end). Invalid or inverted bounds return Error.

take

Signature: take(s: string, n: int) -> string

Returns at most the first n bytes of s. Clamps; never fails.

termClear

Signature: termClear() -> int

Clears the terminal screen.

termCols

Signature: termCols() -> int

Returns the terminal width in columns.

termHideCursor

Signature: termHideCursor() -> int

Hides the terminal cursor.

termMoveCursor

Signature: termMoveCursor(row: int, col: int) -> int

Moves the terminal cursor to the given row and column.

termRawMode

Signature: termRawMode(enabled: int) -> Unit

Enables (1) or disables (0) raw terminal input mode, so keypresses arrive unbuffered.

termReadKey

Signature: termReadKey() -> Result<string, Error>

Reads a single keypress from the terminal and returns it as a string.

termRows

Signature: termRows() -> int

Returns the terminal height in rows.

termShowCursor

Signature: termShowCursor() -> int

Shows the terminal cursor.

test

Signature: test(name: string, body: () -> t0) -> Unit

Runs body as one named test case and prints a TAP result line. A case fails when any assertion inside it fails; the program exits non-zero if any case failed.