blockgame/mods/bg_stoneworking/recipe.lua

local modname = minetest.get_current_modname()

blockgame.crafting.register_pummel_recipe({
	label = "pummel stone into tile",
	used_item = "bg_terrain:cobblestone",
	target_node = "bg_terrain:cobblestone",
	check = function (pos, used_node, target_node)
		local below_node = minetest.get_node(pos + blockgame.vector.dirs.down)
		local stoney_value = minetest.get_item_group(below_node.name, "stoney")
		return stoney_value ~= 0 and stoney_value ~= nil
	end,
	on_success = function (pos, used_node, target_node)
		minetest.set_node(pos, {name = modname .. ":tile"})
	end,
})

blockgame.crafting.register_pummel_recipe({
	label = "pummel tile into bricks",
	used_item = "bg_terrain:cobblestone",
	target_node = modname .. ":tile",
	check = function (pos, used_node, target_node)
		local below_node = minetest.get_node(pos + blockgame.vector.dirs.down)
		local stoney_value = minetest.get_item_group(below_node.name, "stoney")
		return stoney_value ~= 0 and stoney_value ~= nil
	end,
	on_success = function (pos, used_node, target_node)
		minetest.set_node(pos, {name = modname .. ":bricks"})
	end,
})