`class RangeMap`

A map that associates one or more ranges with a value for efficient lookup.

Definitions

`def initialize`

Initialize a new RangeMap.

Implementation

def initialize
	@entries = []
end

`def add(ranges, value)`

Add one or more ranges associated with a value to the map.

Signature

parameter　ranges　Range | Array(Range): The ranges to map.
parameter　value　Object: The value to associate with the ranges.
returns　Object: The added value.

Implementation

def add(ranges, value)
	ranges = [ranges] if ranges.is_a?(Range)
	@entries << [ranges, value]
	return value
end

`def find(key)`

Find the value associated with a key within any range.

Signature

parameter　key　Object: The key to find.
yields　{...}: Block called if no range contains the key.
returns　Object: The value if found, result of block if given, or nil.

Implementation

def find(key)
	@entries.each do |ranges, value|
		return value if ranges.any?{|range| range.include?(key)}
	end
	if block_given?
		return yield
	end
	return nil
end

`def each`

Iterate over each mapped value.

Signature

yields　{|value| ...}: Block called for each value.
parameter　value　Object: The value associated with one or more ranges.

Implementation

def each
	@entries.each do |_, value|
		yield value
	end
end

`def sample`

Get a random value from the map.

Signature

returns　Object: A randomly selected value, or nil if map is empty.

Implementation

def sample
	return nil if @entries.empty?
	_, value = @entries.sample
	return value
end

`def clear`

Clear all ranges from the map.

Implementation

def clear
	@entries.clear
end