/typst-author

Array

A sequence of values.

You can construct an array by enclosing a comma-separated sequence of values in parentheses. The values do not have to be of the same type.

You can access and update array items with the .at() method. Indices are zero-based and negative indices wrap around to the end of the array. You can iterate over an array using a for loop. Arrays can be added together with the + operator, joined together and multiplied with integers.

Note: An array of length one needs a trailing comma, as in (1,). This is to disambiguate from a simple parenthesized expressions like (1 + 2) * 3. An empty array is written as ().

Example

#let values = (1, 7, 4, -3, 2)

#values.at(0) \
#(values.at(0) = 3)
#values.at(-1) \
#values.find(calc.even) \
#values.filter(calc.odd) \
#values.map(calc.abs) \
#values.rev() \
#(1, (2, 3)).flatten() \
#(("A", "B", "C")
    .join(", ", last: " and "))

Constructor

array

Converts a value to an array.

Note that this function is only intended for conversion of a collection-like value to an array, not for creation of an array from individual items. Use the array syntax (1, 2, 3) (or (1,) for a single-element array) instead.

#let hi = "Hello 😃"
#array(bytes(hi))

#array(
  value
) -> array

Parameters

• value:
  • description: The value that should be converted to an array.
  • type: bytes | array | version
  • default: None

Methods

array.len

The number of values in the array.

array.first

Returns the first item in the array. May be used on the left-hand side an assignment. Returns the default value if the array is empty or fails with an error is no default value was specified.

#array.first(
  default: any
) -> any

Parameters

• default:
  • description: A default value to return if the array is empty.
  • type: any
  • default: None

array.last

Returns the last item in the array. May be used on the left-hand side of an assignment. Returns the default value if the array is empty or fails with an error is no default value was specified.

#array.last(
  default: any
) -> any

Parameters

• default:
  • description: A default value to return if the array is empty.
  • type: any
  • default: None

array.at

Returns the item at the specified index in the array. May be used on the left-hand side of an assignment. Returns the default value if the index is out of bounds or fails with an error if no default value was specified.

#array.at(
  index,
  default: any
) -> any

Parameters

• index:
  • description: The index at which to retrieve the item. If negative, indexes from the back.
  • type: int
  • default: None
• default:
  • description: A default value to return if the index is out of bounds.
  • type: any
  • default: None

array.push

Adds a value to the end of the array.

#array.push(
  value
) -> 

Parameters

• value:
  • description: The value to insert at the end of the array.
  • type: any
  • default: None

array.pop

Removes the last item from the array and returns it. Fails with an error if the array is empty.

array.insert

Inserts a value into the array at the specified index, shifting all subsequent elements to the right. Fails with an error if the index is out of bounds.

To replace an element of an array, use at.

#array.insert(
  index,
  value
) -> 

Parameters

• index:
  • description: The index at which to insert the item. If negative, indexes from the back.
  • type: int
  • default: None
• value:
  • description: The value to insert into the array.
  • type: any
  • default: None

array.remove

Removes the value at the specified index from the array and return it.

#array.remove(
  index,
  default: any
) -> any

Parameters

• index:
  • description: The index at which to remove the item. If negative, indexes from the back.
  • type: int
  • default: None
• default:
  • description: A default value to return if the index is out of bounds.
  • type: any
  • default: None

array.slice

Extracts a subslice of the array. Fails with an error if the start or end index is out of bounds.

#array.slice(
  start,
  end,
  count: int
) -> array

Parameters

• start:
  • description: The start index (inclusive). If negative, indexes from the back.
  • type: int
  • default: None
• end:
  • description: The end index (exclusive). If omitted, the whole slice until the end of the array is extracted. If negative, indexes from the back.
  • type: none | int
  • default: none
• count:
  • description: The number of items to extract. This is equivalent to passing start + count as the end position. Mutually exclusive with end.
  • type: int
  • default: None

array.contains

Whether the array contains the specified value.

This method also has dedicated syntax: You can write 2 in (1, 2, 3) instead of (1, 2, 3).contains(2).

#array.contains(
  value
) -> bool

Parameters

• value:
  • description: The value to search for.
  • type: any
  • default: None

array.find

Searches for an item for which the given function returns true and returns the first match or none if there is no match.

#array.find(
  searcher
) -> any none

Parameters

• searcher:
  • description: The function to apply to each item. Must return a boolean.
  • type: function
  • default: None

array.position

Searches for an item for which the given function returns true and returns the index of the first match or none if there is no match.

#array.position(
  searcher
) -> none int

Parameters

• searcher:
  • description: The function to apply to each item. Must return a boolean.
  • type: function
  • default: None

array.range

Create an array consisting of a sequence of numbers.

If you pass just one positional parameter, it is interpreted as the end of the range. If you pass two, they describe the start and end of the range.

This function is available both in the array function's scope and globally.

#range(5) \
#range(2, 5) \
#range(20, step: 4) \
#range(21, step: 4) \
#range(5, 2, step: -1)

#array.range(
  start,
  end,
  step: int
) -> array

Parameters

• start:
  • description: The start of the range (inclusive).
  • type: int
  • default: 0
• end:
  • description: The end of the range (exclusive).
  • type: int
  • default: None
• step:
  • description: The distance between the generated numbers.
  • type: int
  • default: 1

array.filter

Produces a new array with only the items from the original one for which the given function returns true.

#array.filter(
  test
) -> array

Parameters

• test:
  • description: The function to apply to each item. Must return a boolean.
  • type: function
  • default: None

array.map

Produces a new array in which all items from the original one were transformed with the given function.

#array.map(
  mapper
) -> array

Parameters

• mapper:
  • description: The function to apply to each item.
  • type: function
  • default: None

array.enumerate

Returns a new array with the values alongside their indices.

The returned array consists of (index, value) pairs in the form of length-2 arrays. These can be destructured with a let binding or for loop.

#for (i, value) in ("A", "B", "C").enumerate() {
  [#i: #value \ ]
}

#("A", "B", "C").enumerate(start: 1)

#array.enumerate(
  start: int
) -> array

Parameters

• start:
  • description: The index returned for the first pair of the returned list.
  • type: int
  • default: 0

array.zip

Zips the array with other arrays.

Returns an array of arrays, where the ith inner array contains all the ith elements from each original array.

If the arrays to be zipped have different lengths, they are zipped up to the last element of the shortest array and all remaining elements are ignored.

This function is variadic, meaning that you can zip multiple arrays together at once: (1, 2).zip(("A", "B"), (10, 20)) yields ((1, "A", 10), (2, "B", 20)).

#array.zip(
  exact: bool,
  others
) -> array

Parameters

• exact:
  • description: Whether all arrays have to have the same length. For example, (1, 2).zip((1, 2, 3), exact: true) produces an error.
  • type: bool
  • default: false
• others:
  • description: The arrays to zip with.
  • type: array
  • default: None

array.fold

Folds all items into a single value using an accumulator function.

#let array = (1, 2, 3, 4)
#array.fold(0, (acc, x) => acc + x)

#array.fold(
  init,
  folder
) -> any

Parameters

• init:
  • description: The initial value to start with.
  • type: any
  • default: None
• folder:
  • description: The folding function. Must have two parameters: One for the accumulated value and one for an item.
  • type: function
  • default: None

array.sum

Sums all items (works for all types that can be added).

#array.sum(
  default: any
) -> any

Parameters

• default:
  • description: What to return if the array is empty. Must be set if the array can be empty.
  • type: any
  • default: None

array.product

Calculates the product of all items (works for all types that can be multiplied).

#array.product(
  default: any
) -> any

Parameters

• default:
  • description: What to return if the array is empty. Must be set if the array can be empty.
  • type: any
  • default: None

array.any

Whether the given function returns true for any item in the array.

#array.any(
  test
) -> bool

Parameters

• test:
  • description: The function to apply to each item. Must return a boolean.
  • type: function
  • default: None

array.all

Whether the given function returns true for all items in the array.

#array.all(
  test
) -> bool

Parameters

• test:
  • description: The function to apply to each item. Must return a boolean.
  • type: function
  • default: None

array.flatten

Combine all nested arrays into a single flat one.

array.rev

Return a new array with the same items, but in reverse order.

array.split

Split the array at occurrences of the specified value.

#(1, 1, 2, 3, 2, 4, 5).split(2)

#array.split(
  at
) -> array

Parameters

• at:
  • description: The value to split at.
  • type: any
  • default: None

array.join

Combine all items in the array into one.

#array.join(
  separator,
  last: any,
  default: any | none
) -> any

Parameters

• separator:
  • description: A value to insert between each item of the array.
  • type: any | none
  • default: none
• last:
  • description: An alternative separator between the last two items.
  • type: any
  • default: None
• default:
  • description: What to return if the array is empty.
  • type: any | none
  • default: none

array.intersperse

Returns an array with a copy of the separator value placed between adjacent elements.

#("A", "B", "C").intersperse("-")

#array.intersperse(
  separator
) -> array

Parameters

• separator:
  • description: The value that will be placed between each adjacent element.
  • type: any
  • default: None

array.chunks

Splits an array into non-overlapping chunks, starting at the beginning, ending with a single remainder chunk.

All chunks but the last have chunk-size elements. If exact is set to true, the remainder is dropped if it contains less than chunk-size elements.

#let array = (1, 2, 3, 4, 5, 6, 7, 8)
#array.chunks(3) \
#array.chunks(3, exact: true)

#array.chunks(
  chunk-size,
  exact: bool
) -> array

Parameters

• chunk-size:
  • description: How many elements each chunk may at most contain.
  • type: int
  • default: None
• exact:
  • description: Whether to keep the remainder if its size is less than chunk-size.
  • type: bool
  • default: false

array.windows

Returns sliding windows of window-size elements over an array.

If the array length is less than window-size, this will return an empty array.

#let array = (1, 2, 3, 4, 5, 6, 7, 8)
#array.windows(5)

#array.windows(
  window-size
) -> array

Parameters

• window-size:
  • description: How many elements each window will contain.
  • type: int
  • default: None

array.sorted

Return a sorted version of this array, optionally by a given key function. The sorting algorithm used is stable.

Returns an error if a pair of values selected for comparison could not be compared, or if the key or comparison function (if given) yield an error.

To sort according to multiple criteria at once, e.g. in case of equality between some criteria, the key function can return an array. The results are in lexicographic order.

#let array = (
  (a: 2, b: 4),
  (a: 1, b: 5),
  (a: 2, b: 3),
)
#array.sorted(key: it => (it.a, it.b))

#array.sorted(
  key: function,
  by: function
) -> array

Parameters

• key:
  • description: If given, applies this function to each element in the array to determine the keys to sort by.
  • type: function
  • default: None
• by:
  • description: If given, uses this function to compare every two elements in the array. The function will receive two elements in the array for comparison, and should return a boolean indicating their order: true indicates that the elements are in order, while false indicates that they should be swapped. To keep the sort stable, if the two elements are equal, the function should return true. If this function does not order the elements properly (e.g., by returning false for both (x, y) and (y, x), or for (x, x)), the resulting array will be in unspecified order. When used together with key, by will be passed the keys instead of the elements. typst #( "sorted", "by", "decreasing", "length", ).sorted( key: s => s.len(), by: (l, r) => l >= r, )
  • type: function
  • default: None

array.dedup

Deduplicates all items in the array.

Returns a new array with all duplicate items removed. Only the first element of each duplicate is kept.

#(3, 3, 1, 2, 3).dedup()

#array.dedup(
  key: function
) -> array

Parameters

• key:
  • description: If given, applies this function to each element in the array to determine the keys to deduplicate by. typst #("apple", "banana", " apple ").dedup(key: s => s.trim())
  • type: function
  • default: None

array.to-dict

Converts an array of pairs into a dictionary. The first value of each pair is the key, the second the value.

If the same key occurs multiple times, the last value is selected.

#(
  ("apples", 2),
  ("peaches", 3),
  ("apples", 5),
).to-dict()

array.reduce

Reduces the elements to a single one, by repeatedly applying a reducing operation.

If the array is empty, returns none, otherwise, returns the result of the reduction.

The reducing function is a closure with two arguments: an "accumulator", and an element.

For arrays with at least one element, this is the same as array.fold with the first element of the array as the initial accumulator value, folding every subsequent element into it.

#let array = (2, 1, 4, 3)
#array.reduce((acc, x) => calc.max(acc, x))

#array.reduce(
  reducer
) -> any

Parameters

• reducer:
  • description: The reducing function. Must have two parameters: One for the accumulated value and one for an item.
  • type: function
  • default: None