HAND (Hold And Notation Designator) implementation for the Ruby language.
HAND (Hold And Notation Designator) is a standardized notation for representing piece reserve locations in board games where pieces can be held off-board and potentially placed. This applies to games like Shōgi, Crazyhouse, Go, and other games featuring reserve mechanics.
This gem implements the HAND Specification v1.0.0, providing a minimalist Ruby interface using a single character: * (asterisk).
# In your Gemfile
gem "sashite-hand"Or install manually:
gem install sashite-handrequire "sashite/hand"
# Check if a location represents the reserve
Sashite::Hand.reserve?("*") # => true
Sashite::Hand.reserve?("a1") # => false
Sashite::Hand.reserve?("**") # => false
# Get the canonical representation
Sashite::Hand.to_s # => "*"# From reserve to board
source = "*"
destination = "e4"
puts "#{source} → #{destination}" # => "* → e4"
# Shōgi piece drop
puts "Dropping piece from reserve to 5e" if Sashite::Hand.reserve?("*")
# Go stone placement
supply = "*"
puts "Placing stone from supply to dd" if Sashite::Hand.reserve?(supply)HAND complements the CELL specification for complete location coverage:
def valid_location?(location)
Sashite::Cell.valid?(location) || Sashite::Hand.reserve?(location)
end
valid_location?("*") # => true (reserve)
valid_location?("a1") # => true (board position)Sashite::Hand.reserve?(location)- Check if location represents the reserveSashite::Hand.to_s- Get the canonical HAND representation ("*")
Sashite::Hand::RESERVE- The reserve location character ("*")
- Minimalist: Single character (
*) for all reserve operations - Universal: Works across different board game systems
- Rule-agnostic: Independent of specific reserve mechanics
- Complementary: Designed to work with CELL coordinates
Following the Game Protocol:
| Protocol Attribute | HAND Encoding | Meaning |
|---|---|---|
| Location | * |
Any off-board reserve area |
Available as open source under the MIT License.
Maintained by Sashité — promoting chess variants and sharing the beauty of board game cultures.