Factorio Stdlib

Vendor.Enumerable classmod

A collection library to simplify sequential table operations

local Enumerable = require('__stdlib__/stdlib/vendor/enumerable')
Enumerable.create({1,2,3})

• Author: Billiam

Tables

Methods

Tables

# Vendor.Enumerable._data

Internal collection data

Methods

# Vendor.Enumerable:create(collection)

Enumerable constructor.

If no collection is provided, a new empty table will be generated.

Parameters:

• collection : (optional table) Sequential table to wrap

Returns:

• (enumerable) A new collection instance

Raises

‘Enumerable data must be a sequence’ if given a non-sequential table Usage:

collection = Enumerable.create({123})

# Vendor.Enumerable:data()

Return the unwrapped collection data.

Returns:

• (table)

Usage:

collectionData = collection:to_table()

# Vendor.Enumerable:to_table()

Create a shallow copy of the unwrapped collection data.

Returns:

• (table)

Usage:

clonedData = collection:to_table()

# Vendor.Enumerable:each(callback)

Pass all elements in the collection to a callback.

Parameters:

• callback : (callable)

Returns:

• (enumerable) The collection instance

Usage:

collection:each(function(value, index) ... end)

# Vendor.Enumerable:map(callback)

Pass all elements in collection to a callback.

returns a new enumerable instance containing values returned by the callback.

Parameters:

• callback : (callable)

Returns:

• (enumerable) New enumerable instance

Usage:

collection = Enumerable.create({1, 2, 3})
collection:map(function(value, index) return value* 2 end)
> Enumerable containing {2, 4, 6}

# Vendor.Enumerable:find_index(callback)

Find the position of the first item in collection for which the callback returns true.

Parameters:

• callback : (callable)

Returns:

• (int) the position of the matched element

Usage:

collection = Collection.create({0, 1, 2, 3, 4})
collection:findIndex(function(value, index) return value > 2 end)
-> 4

# Vendor.Enumerable:empty()

Whether the collection has no elements.

Returns:

• (bool)

Usage:

collection = Enumerable.create()
 if collection:empty() then
   print('Collection is empty')
 end
 -> Collection is empty

# Vendor.Enumerable:first(n)

Return the first element or elements in the collection.

Parameters:

• n : (optional int) Number of elements to return. If absent, the first item will be returned.

Returns:

• (table or *)

See also:

• Enumerable:last

Usage:

collection = Enumerable.create({1,2,3,4})
collection:first()
-> 1
collection:first(3)
-> {1,2,3}

# Vendor.Enumerable:last(n)

Return the last element or elements in the collection.

Parameters:

• n : (optional int) Number of elements to return. If absent, the last item will be returned.

Returns:

• (table)

See also:

• Enumerable:first

Usage:

collection = Enumerable.create({1,2,3,4})
collection:last()
-> 4
collection:last(3)
-> {2, 3, 4}

# Vendor.Enumerable:count(callback)

Return the number of items in the collection.

If a callback is given, count will return the number of elements for which the callback returns true

Parameters:

• callback : (callable) Callback used to determine whether element should be counted

Returns:

• (int)

Usage:

collection = Enumerable.create({1,2,3})
collection:count()
-> 3
collection:count(function(value, index) return value % 2 == 0 end)
-> 1

# Vendor.Enumerable:concat(other)

Append the contents of one table onto the end of the existing enumerable.

Parameters:

• other : (table) Table with content to append to enumerable

Returns:

• (enumerable) The enumerable instance

Usage:

pets = Enumerable:create({'dog', 'cat'})
pets:concat({'turtle', 'wizard'})
-> pets now contains {'dog', 'cat', 'turtle', 'wizard'}

# Vendor.Enumerable:reduce(initial, callback)

Combine elements of enumerable by passing all items to a callback.

Values returned by the callback will be used as the accumulator value for subsequent callbacks.

Parameters:

• initial : (optional int) Initial value for accumulator
• callback : (callable)

Returns:

• Accumulator value

Usage:

numbers = Enumerable.create({1,2,3})
numbers:reduce(function(accumulator, value) return (accumulator or 0) + value end)
-> 6
numbers:reduce(20, function(accumulator, value) return accumulator + value end)
-> 26

# Vendor.Enumerable:min(callback)

Find the lowest value in the enumerable instance.

If a callback is provided, the return value will be used to determine the lowest value.

Parameters:

• callback : (optional callable)

Returns:

• Lowest value

Usage:

strings = Enumerable.create({'aaaaaa', 'bbb', 'c'})
strings:min()
> 'aaaaa'
strings:min(function(value) return #value end)
> 'c'

# Vendor.Enumerable:max(callback)

Find the highest value in the enumerable instance.

If a callback is provided, the return value will be used to determine the highest value.

Parameters:

• callback : (optional callable)

Returns:

• Highest value

Usage:

strings = Enumerable.create({'aaaaaa', 'bbb', 'c'})
strings:max()
> 'c'
strings:max(function(value) return #value end)
> 'aaaaa'

# Vendor.Enumerable:minmax(callback)

Find the highest and lowest values in the enumerable.

If a callback is provided, the return value will be used to determine the highest and lowest values.

Parameters:

• callback : (optional callable)

Returns:

• Lowest value
• Highest value

Usage:

numbers = Enumerable.create({6,3,1,5,2,4})
lowest, highest = numbers:minmax()
> (1,6)
strings:max(function(value) return 10 - value end)
> (6, 1)

# Vendor.Enumerable:sort(callback)

Sort the enumerable by optional callback in place.

If a callback is not provided, data will be sorted in ascending order. If callback is provided, it will be passed two table elements, and should return true if the first element should appear first, otherwise false. See also: table.sort documentation

Parameters:

• callback : (optional callable) sort method

Returns:

• (enumerable) The collection instance

Usage:

numbers = Enumerable.create({2,1,3})
numbers:sort()
-> numbers now contains {1,2,3}
numbers:sort(function(a, b) return b < a end)
-> numbers now contains {3,2,1}

# Vendor.Enumerable:push(...)

Add one or more items to the enumerable.

Parameters:

• ... : Items to append

Returns:

• (enumerable) The collection instance

Usage:

items = Enumerable.create({1,2,3})
items:push(4, 5)
> items contains {1,2,3,4,5}

# Vendor.Enumerable:pop()

Remove and return the last item from the collection.

Returns:

• (enumerable) The collection instance

Usage:

items = Enumerable.create({1,2,3})
items:pop()
> returns 3
> items now contains {1,2}

# Vendor.Enumerable:shift()

Remove and return the first item from the collection.

Returns:

• (enumerable) The collection instance

Usage:

items = Enumerable.create({1,2,3})
items:shift()
> returns 1
> items now contains {2,3}

# Vendor.Enumerable:unshift(...)

Insert one or more items into the beginning of the collection.

Parameters:

• ... : Elements to insert

Returns:

• (enumerable) The collection instance

Usage:

items = Enumerable.create({4,5,6})
items:unshift(1,2,3)
-> Items now contains {1,2,3,4,5,6}

# Vendor.Enumerable:find(callback)

Returns the first element in the collection where the callback returns true.

Parameters:

• callback : (callable)

Returns:

• Matching item

Usage:

numbers = Enumerable.create({20, 30, 40})
numbers:find(function(value, index) return value > 25 end)
-> 30

# Vendor.Enumerable:reject(callback)

Create a new collection with elements which the callback returns false.

Parameters:

• callback : (callable)

Returns:

• (enumerable) New collection instance

Usage:

items = Enumerable.create({1,2,3,4,5,6})
odd = Enumerable:reject(function(value, index) return value % 2 == 0 end)
-> Enumerable containing {1,3,5}

# Vendor.Enumerable:select(callback)

Create a new collection with elements which the callback returns true.

Parameters:

• callback : (callable)

Returns:

• (enumerable) New collection instance

Usage:

items = Enumerable.create({1,2,3,4,5,6})
even = Enumerable:select(function(value, index) return value % 2 == 0 end)
-> Enumerable containing {2,4,6}

# Vendor.Enumerable:all(callback)

Returns true if callback returns truthy for all elements in the collection.

Parameters:

• callback : (callable)

Returns:

• (bool)

Usage:

items = Enumerable.create({10, 20, 30})
items:all(function(value, index) return value > 5 end)
-> true
items:all(function(value, index) return value < 25 end)
-> false

# Vendor.Enumerable:any(callback)

Returns true if callback returns truthy for any element in the collection.

Parameters:

• callback : (callable)

Returns:

• (bool)

Usage:

items = Enumerable.create({10, 20, 30})
items:any(function(value, index) return value > 25 end)
-> true
items:any(function(value, index) return value > 30 end)
-> false

# Vendor.Enumerable:group_by(callback)

Groups elements into collections based on the result of the provided callback.

Resulting table will have keys matching the returned value of the callback, and values as a table of elements which returned that value.

Parameters:

• callback : (callable)

Returns:

• (table)

Usage:

numbers = Enumerable.create({1,2,3,4,5,6})
result = Enumerable.group_by(function(value, index) return value % 3 end)
result[0]
-> Enumerable containing {3, 6}
result[1]
-> Enumerable containing {2, 5}
result[2]
-> Enumerable containing {1, 4}

# Vendor.Enumerable:partition(callback)

Split enumerable into two groups, based on the true or false result of the callback.

Aliases: find_all, detect

Parameters:

• callback : (callable)

Returns:

• (enumerable) Collection containing items which returned true
• (enumerable) Collection containing items which returned false

Usage:

numbers = Enumerable.create({1,2,3,4,5,6})
ven, odd = Enumerable:partition(function(value, index) return value % 2 == 1 end)
> even is a collection containing {2, 4, 6}
> odd is a collection containing {1, 3, 5}

# Vendor.Enumerable:find_all()

See also:

• Enumerable:select

# Vendor.Enumerable:detect()

See also:

• Enumerable:select

# Vendor.Enumerable:collect()

See also:

• Enumerable:map

# Vendor.Enumerable:inject()

See also:

• Enumerable:reduce