Description
This library makes it easy to provide a complex API for Lua scripts. It uses RLua internally and therefore it has the same compatibility and restrictions.
Example code
Lets say we have these classes:
User = Struct.new(:name, :favorite_food, :age)
Food = Struct.new(:name, :cooking_time) do
def prepare(timer)
if timer == cooking_time
"This #{name} is delicious"
elsif timer > cooking_time
"This #{name} is awfully burnt"
else
"Smells like frozen #{name}..."
end
end
def buy(*)
'Got one'
end
end
Pizza = Food.new('Pizza', 16)
Lasagne = Food.new('Lasagne', 40)
class Sandbox
def get(username)
users.detect { |u| u.name == username }
end
def users
[
User.new('Kyle', Pizza, 43),
User.new('Lisa', Pizza, 25),
User.new('Ben', Lasagne, 6),
]
end
endTo make it available to our Lua script we can use this code:
require 'transparent_lua'
tlua = TransparentLua.new(Sandbox.new)
tlua.call(<<-EOF)
print(get_user('Kyle').name .. " likes " .. get_user('Kyle').favorite_food.name .. ".");
print(get_user('Kyle').favorite_food.buy());
print("It needs to cook exactly " .. get_user('Kyle').favorite_food.cooking_time .. " minutes");
my_cooking_time = 270;
print(get_user('Kyle').name .. " cooks it for " .. my_cooking_time .. " minutes.");
print(get_user('Kyle').favorite_food.prepare(my_cooking_time));
EOF
Pizza.cooking_time = 270
tlua.call(<<-EOF)
print("Lets try it again for " .. my_cooking_time .. " minutes. Maybe it works now...");
print(get_user('Kyle').name .. " cooks it for " .. my_cooking_time .. " minutes.");
print(get_user('Kyle').favorite_food.prepare(my_cooking_time));
EOFTypes of methods
- Methods without arguments are created as index of the Lua table
- Methods with arguments are created as a callable metatable.
- To make clear, that an argumentless method is a method (
food.buy()vs.food.buy), discard any arguments (def buy(*))
Type conversion
In addition to RLuas type conversion, this library converts Lua tables to either Hashes or Arrays (when all keys are Numeric).