Jule Manual

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builtin ​

Index ​

Variables
type i8
type i16
type i32
type i64
type u8
type u16
type u32
type u64
type f32
type f64
type int
type uint
type uintptr
type str
type bool
type any
type byte
type rune
fn print(v)
fn println(v)
fn panic(message: str)
fn make(T, ...V): T
fn copy(mut dest: Dest, mut src: Src): int
fn append(mut dest: []T, mut items: ...T): []T
fn len(T): int
fn cap(T): int
fn delete(mut map[K]V, ...)
fn new(T, ...T): &T
fn close(c: chan<- T)

Variables ​

jule
const true = 1 == 1

Logical true.

jule
const false = !true

Logical false.

jule
const nil = nil

Nil memory.

i8 ​

jule
type i8: i8

Signed 8-bit integer.

i16 ​

jule
type i16: i16

Signed 16-bit integer.

i32 ​

jule
type i32: i32

Signed 32-bit integer.

i64 ​

jule
type i64: i64

Signed 64-bit integer.

u8 ​

jule
type u8: u8

Unsigned 8-bit integer.

u16 ​

jule
type u16: u16

Unsigned 16-bit integer.

u32 ​

jule
type u32: u32

Unsigned 32-bit integer.

u64 ​

jule
type u64: u64

Unsigned u64-bit integer.

f32 ​

jule
type f32: f32

32-bit floating-point.

f64 ​

jule
type f64: f64

64-bit floating-point.

int ​

jule
type int: int

It is a platform dependent integer type.

uint ​

jule
type uint: uint

It is a platform dependent unsigned integer type.

uintptr ​

jule
type uintptr: uintptr

It is a platform dependent unsigned integer type that is big enough to hold a pointer. Can used for casting pointers to integers.

str ​

jule
type str: str

UTF-8 byte encoded character string. See for more information: http://manual.jule.dev/introduction/data-types#string

bool ​

jule
type bool: bool

Boolean type for logical expressions.

any ​

jule
type any: any

It can be hold any data type and nil. See for more information: https://manual.jule.dev/dynamic-types/any

byte ​

jule
type byte: byte

Is an alias for u8. It is used, by convention, to distinguish byte values from 8-bit unsigned integer values.

rune ​

jule
type rune: rune

Is an alias for i32. It is used, by convention, to distinguish character values from integer values.

print ​

jule
fn print(t: T)

Prints t to stdout.

Before printing the value will be converted to string. For string conversion, Jule's runtime package will be used, always. For types that contain special string conversion functions, such as structures, those functions are called for conversion.

String conversion implementation of runtime package may not be exact for some types compared to other conversion implementations which is provided by other standard library packages such as "std/conv".

println ​

jule
fn println(t: T)

This function same with the out function. One difference, prints new line after print.

panic ​

jule
fn panic(message: str)

Panics program with given error message. This panics are not recoverable.

make ​

jule
fn make(T, ...V): T

Returns new instance of data type for supported types.

Slices:

Allocates slices dynamically. In addition
to the slice type, it can take two more arguments.
The first argument is mandatory. The first argument
specifies the length of the slice. The second argument
specifies the capacity of the slice and is optional.
The slice is returned with its length, and the field within its
length is initialized with the default value.
For []byte types, variadic strings are allowed,
such as: append(bytes, "foo"...)

Channels:

Channels can only take a type parameter or a buffer capacity length.
When a channel is initialized without capacity, it creates an unbuffered channel.
If a capacity is provided, a buffered channel is created.
Capacities smaller than zero result in a panic.
If capacity is equals to zero, then an unbuffered channel will be created.

copy ​

jule
fn copy(mut dest: Dest, mut src: Src): int

The copy built-in function copies elements from a source slice into a destination slice. (As a special case, it also will copy bytes from a string to a slice of bytes.) The source and destination may overlap, it is safe. Returns the number of elements copied, which will be the minimum of len(src) and len(dst).

Arrays:

The dest parameter may be array slicing.
Slicing is allowed for arrays on mutable memory.
Thus, the changes will be reflected in the array.

For example:

	mut x := [5]int([0, ...])
	println(x)
	copy(x[:], [1, 2, 3, 4, 5, 6])
	println(x)

In the example code above, x will be sliced with mutable memory.
So copy operation will directly affect the x array.

This only applies to the last sliced array.
Previous slicings may result in memory allocation, and changes may not be reflected.

For example:

	mut x := [3][5]int([])
	copy(x[:][1][:], [1, 2, 3, 4, 5])
	println(x[1])

In the example code above, the x[1] array will not be mutated.
Because x[:] expression will allocate a new slice with copy of arrays.

append ​

jule
fn append(mut dest: []T, mut items: ...T): []T

If there is enough capacity, it adds to the destination slice. If there is not enough capacity, it creates a copy of the destination slice with enough capacity and adds the new elements and returns the new allocation.

len ​

jule
fn len(T): int

Returns length of T.

For slices:

Returns length of slice, aka count of slice elements.
If slice is nil, returns zero.

For strings:

Returns length of string, aka count of string's bytes.

For arrays:

Returns length of array, also means total capacity of array.

For maps:

Returns count of key-value pairs of map.
If map is nil, returns zero.

cap ​

jule
fn cap(T): int

Returns capacity of T.

For slices:

Returns capacity of slice, aka possible maximum count of slice elements without
expanding buffer.

delete ​

jule
fn delete(mut map[K]V, ...)

Deletes key from map. It takes two argument. The first one is map, second one is the key. If just given one argument, this one is a map, and clears all keys of map.

new ​

jule
fn new(T, ...T): &T

Returns new smart pointer for T initialized with default for type. It may take two arguments. The second argument used as initialization expression for memory allocation.

close ​

jule
fn close(c: chan<- T)

Closes channel c. It should be executed only by the sender, never the receiver, and has the effect of shutting down the channel after the last sent value is received. After the last value has been received from a closed channel c, any receive from c will succeed without blocking, returning the zero value for the channel element.