list

The list package adds predicate helpers and searches to lists. Because the package extends the list type, most functions can also be called as methods:

nums = [3, 8, 1, 8, 5]

println nums.reject(do (n) => n > 4)          # [3, 1]
println nums.first_where(do (n) => n > 4)     # 8
println nums.last_where(do (n) => n > 4)      # 5
println nums.one(do (n) => n == 1)            # true
println nums.is_unique()                      # false
println nums.index_of(8)                      # 1
println nums.last_index_of(8)                 # 3
println [1, 2.5, "x", 3].sum_integer()        # 4

A few functions share their names with built-in methods or type keywords. The built-in wins when called as a method, so call these with the package prefix:

nums = [3, 8, 1, 8, 5]

println list::any(nums, do (n) => n > 7)      # true
println list::none(nums, do (n) => n > 9)     # true
println list::all(nums, do (n) => n > 0)      # true
println list::count(nums, do (n) => n == 8)   # 2
println list::find(nums, do (n) => n == 8)    # 1 (the index)

list::iterator(xs), or xs.iterator(), returns a ListIterator.

Functions

list::iterator

list::iterator(_list: list)

Creates an iterator over a list.

Parameter	Type	Default	Description
_list	list		The list to iterate over.

Returns object — A ListIterator instance.

list::all

list::all(_list: list, _predicate: lambda): boolean

Returns true if every element in the list satisfies the predicate.

Parameter	Type	Default	Description
_list	list		The list to test.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns boolean — true if all elements satisfy the predicate, false otherwise.

list::any

list::any(_list: list, _predicate: lambda): boolean

Returns true if any element in the list satisfies the predicate.

Parameter	Type	Default	Description
_list	list		The list to test.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns boolean — true if at least one element satisfies the predicate.

list::count

list::count(_list: list, _predicate: lambda): integer

Returns the count of elements satisfying the predicate.

Parameter	Type	Default	Description
_list	list		The list to test.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns integer — The number of matching elements.

list::find

list::find(_list: list, _predicate: lambda): integer

Finds the index of the first element satisfying the predicate.

Parameter	Type	Default	Description
_list	list		The list to search.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns integer — The index of the first matching element, or -1 if not found.

list::first_where

list::first_where(_list: list, _predicate: lambda): any

Returns the first element satisfying the predicate, or null.

Parameter	Type	Default	Description
_list	list		The list to search.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns any — The first matching element, or null if none found.

list::index_of

list::index_of(_list: list, _value: any): integer

Returns the first index of a given value in the list.

Parameter	Type	Default	Description
_list	list		The list to search.
_value	any		The value to find.

Returns integer — The index of the first occurrence, or -1 if not found.

list::last_index_of

list::last_index_of(_list: list, _value: any): integer

Returns the last index of a given value in the list.

Parameter	Type	Default	Description
_list	list		The list to search.
_value	any		The value to find.

Returns integer — The index of the last occurrence, or -1 if not found.

list::is_unique

list::is_unique(_list: list): boolean

Returns true if every element in the list is unique.

Parameter	Type	Default	Description
_list	list		The list to check.

Returns boolean — true if all elements are distinct.

list::last_where

list::last_where(_list: list, _predicate: lambda): any

Returns the last element satisfying the predicate, or null.

Parameter	Type	Default	Description
_list	list		The list to search.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns any — The last matching element, or null if none found.

list::none

list::none(_list: list, _predicate: lambda): boolean

Returns true if no element satisfies the predicate.

Parameter	Type	Default	Description
_list	list		The list to test.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns boolean — true if no elements satisfy the predicate.

list::one

list::one(_list: list, _predicate: lambda): boolean

Returns true if exactly one element satisfies the predicate.

Parameter	Type	Default	Description
_list	list		The list to test.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns boolean — true if exactly one element matches.

list::reject

list::reject(_list: list, _predicate: lambda): list

Returns a list of elements that do not satisfy the predicate.

Parameter	Type	Default	Description
_list	list		The source list.
_predicate	lambda		A single-argument lambda returning a boolean.

Returns list — A new list of elements for which the predicate returned false.

list::sum_integer

list::sum_integer(_list: list): integer

Computes the integer sum of all integer elements in the list.

Parameter	Type	Default	Description
_list	list		A list of mixed values (non-integer values are discarded).

Returns integer — The sum of all integer elements.

list::sum_float

list::sum_float(_list: list): float

Parameter	Type	Default	Description
_list	list

Returns float