Chunks

Chunks is a small functional library for Lua, and a port of the original “Chunks” library written in JavaScript.

The annotated source code is available.

Installation

luarocks build https://raw.github.com/gummesson/chunks.lua/master/chunks-dev-1.rockspec

API

Collections

Chunks.each

Chunks.each(tbl, iterator)

Executes the iterator on every item in the tbl.

Examples

local results = {}
Chunks.each({1, 2, 3}, function(v, k)
  table.insert(results, v)
end)
--- {1, 2, 3}

local results = {}
Chunks.each({one = 1, two = 2, three = 3}, function(v, k)
  table.insert(results, v)
end)
--- {1, 2, 3}

Chunks.map

Chunks.map(tbl, iterator)

Returns a new and transformed table by executing the iterator on every item in the tbl.

Examples

Chunks.map({1, 2, 3}, function(v, k)
  return v + 1
end)
-- {2, 3, 4}

Chunks.map({one = 1, two = 2, three = 3}, function(v, k)
  return v + 1
end)
-- {2, 3, 4}

Chunks.filter

Chunks.filter(tbl, iterator)

Returns a new table by executing the iterator on every item in the tbl. Only the items that evalute to true in the iterator will be added to the table.

Examples

Chunks.filter({1, 2, 3}, function(v, k)
  return v > 1
end)
-- {2, 3}

Chunks.filter({one = 1, two = 2, three = 3}, function(v, k)
  return v > 1
end)
-- {2, 3}

Chunks.reduce

Chunks.reduce(tbl, iterator[, memo])

Returns a single value by executing the iterator on every item in the tbl and passing the previous value, memo, to the iterator.

Examples

Chunks.reduce({1, 2, 3}, function(m, v)
  return m + v
end)
-- 6

Chunks.reduce({one = 1, two = 2, three = 3}, function(m, v)
  return m + v
end, 1)
-- 7

Chunks.some

Chunks.some(tbl, iterator)

Returns either true or false by executing the iterator on every item in the tbl. It'll return true if one of the items in the tbl matches the iterator.

Examples

Chunks.some({1, 2, 3}, function(v, k)
  return v == 3
end)
-- true

Chunks.some({one = 1, two = 2, three = 3}, function(v, k)
  return v > 4
end)
-- false

Chunks.every

Chunks.every(tbl, iterator)

Returns either true or false by executing the iterator on every item in the tbl. It'll return true if all of the items in the tbl matches the iterator.

Examples

Chunks.every({1, 2, 3}, function(v, k)
  return v < 5
end)
-- true

Chunks.every({one = 1, two = 2, three = 3}, function(v, k)
  return v > 2
end)
-- false

Chunks.index

Chunks.index(tbl, item)

Returns the index of the item in the tbl.

Examples

Chunks.index({1, 2, 3}, 2)
-- 2

Chunks.index({one = 1, two = 2, three = 3}, 4)
-- nil

Chunks.contains

Chunks.contains(tbl, item)

Determines if the tbl contains the item. Returns either true or false.

Examples

Chunks.contains({1, 2, 3}, 2)
-- true

Chunks.contains({one = 1, two = 2, three = 3}, 4)
-- false

Chunks.size

Chunks.size(tbl)

Returns the size of the tbl.

Examples

Chunks.size({1, 2, 3})
-- 3

Chunks.size({one = 1, two = 2, three = 3})
-- 3

Chunks.clone

Chunks.clone(tbl)

Returns a clone of the tbl.

Examples

Chunks.clone({1, 2, 3})
-- {1, 2, 3}

Chunks.clone({one = 1, two = 2, three = 3})
-- {one = 1, two = 2, three = 3}

Chunks.sort

Chunks.sort(tbl[, comp])

Returns a new table with the values from the tbl sorted, either by the default order or the comp function.

Examples

Chunks.sort({1, 3, 2})
-- {1, 2, 3}

Chunks.sort({one = 1, two = 2, three = 3}, function(a, b) 
  return a > b
end)
-- {3, 2, 1}

Types

Chunks.isArray

Chunks.isArray(tbl)

Determines if the tbl is array-like. Returns either true or false.

Examples

Chunks.isArray({1, 2, 3})
-- true

Chunks.isArray({one = 1, two = 2, three = 3})
-- false

Chunks.isDict

Chunks.isDict(tbl)

Determines if the tbl is dictionary-like. Returns either true or false.

Examples

Chunks.isDict({one = 1, two = 2, three = 3})
-- true

Chunks.isDict({1, 2, 3})
-- false

Arrays

Chunks.first

Chunks.first(tbl)

Returns the first item in the tbl.

Example

Chunks.first({1, 2, 3})
-- 1

Chunks.last

Chunks.last(tbl)

Returns the last item in the tbl.

Example

Chunks.last({1, 2, 3})
-- 3

Chunks.flatten

Chunks.flatten(tbl[, memo])

Returns a new table by flattening the nested tables in the tbl. If the memo is provided it'll get used as a starting point for the new table.

Examples

Chunks.flatten({{1}, {{2}, {3}}})
-- {1, 2, 3}

Chunks.flatten({{2}, {{3}, {4}}}, {1})
-- {1, 2, 3, 4}

Dictionaries

Chunks.keys

Chunks.keys(tbl)

Returns a new table with keys from the tbl.

Example

Chunks.keys({one = 1, two = 2, three = 3})
-- {'one', 'two', 'three'}

Chunks.values

Chunks.values(tbl)

Returns a new table with values from the tbl.

Example

Chunks.values({one = 1, two = 2, three = 3})
-- {1, 2, 3}

Chunks.has

Chunks.has(tbl, key)

Determines if the tbl has the key. Returns either true or false.

Example

Chunks.has({one = 1, two = 2, three = 3}, 'two')
-- true

Chunks.extend

Chunks.extend(tbl, src)

Merges the properties in the tbl together with the properties in the src.

Example

Chunks.extend({one = 1, two = 2, three = 3}, {three = 4})
-- {one = 1, two = 2, three = 4}