Map

In this section, you will find multiple functions to work with maps (or dictionaries if you prefer).

In your code, it is encouraged to put this part of the library into a variable:

local Map = Disk.Map

If you are not familiar with this kind of utility functions, don't get overwhelmed and start with these:

• keys
• values
• count
• merge

copy

Makes a shallow copy of a map.

local value = { key = "value" }
local result = Map.copy(value)

print(value == result) -- false
print(value.key == result.key) -- true

count

Returns the number of key-value pairs in the given map.

local result = Map.count({ a = "A", b = "B" })
-- result is 2

Related isEmpty

entries

Create an array of key-value pairs from the map.

local result = Map.entries({ a = "A", b = "B" })
-- result is {{"a", "A"}, {"b", "B"}}

Optionally, two values can be passed to use as object keys when creating the array.

local result = Map.entries({ a = "A", b = "B" }, "letter", "upper")
-- result is {{ letter = "a", upper = "A"}, { letter = "b", upper = "B"}}

invert

Creates a new map by swapping keys and values of the original map.

local result = Map.invert({ a = "A", b = "B" })
-- result is { A = "a", B = "b" }

isEmpty

Returns true if a map has no entries.

local result = Map.isEmpty({ }) --> true
local result = Map.isEmpty({ key = "" }) -- false

Related count

keys

Returns an array containing all the keys of the given map.

local result = keys({ a = true, b = false }) --> { 'a', 'b' }

Note: Lua/Luau does not guarantee the iteration order of maps, so this function does not guarantee the ordering of the keys.

Related values

mapEntries

Returns a new map where each key-value pair is converted with a mapping function. When the mapping function returns a nil value, the entry is removed.

local result = Map.mapEntries({ a = 1, b = 2, c = 3 }, function(key, value)
    return string.upper(key), tostring(value)
end)
-- result is { A = "1", B  = "2", C = "3" }

Related mapValues

mapValues

Returns a new map where each value is converted with a mapping function. When the mapping function returns a nil value, the entry is removed.

local result = Map.mapValues({ a = 1, b = 2, c = 3 }, tostring)
-- result is { a = "1", b  = "2", c = "3" }

Related mapEntries

merge

Merge multiple maps into a single map, with precedence given to the latest maps.

local result = Map.merge({ name = 'John' }, { age = 30 })
-- result is { name = "John", age = 30 }

The function will skipped

remove

Returns a new map with all the given keys removed.

local result = remove({ property = true, other = false }, 'other')
-- result is { property = true }

Note: This function returns the same map if no keys are given

values

Returns an array containing all the values of the given map.

local result = keys({ a = true, b = false }) --> { true, false }

Note: Lua/Luau does not guarantee the iteration order of maps, so this function does not guarantee the ordering of the values.

Related keys