Proof of concept for issue #55.

Still to be completed.

commands.lua

@@ -0,0 +1,86 @@
+require "keys"
+
+Keydef = {}
+Keydef.mt = {} 
+function Keydef.new(keycode,modifier,descr)
+	local keydef = {}
+	keydef.keycode = keycode
+	keydef.modifier = modifier
+	keydef.descr = descr
+	setmetatable(keydef, Keydef.mt)
+	return keydef
+end
+function Keydef.tostring(keydef)
+	return ((keydef.modifier and keydef.modifier.."+") or "").."["..(keydef.keycode or "").."]"..(keydef.descr or "")
+end
+function Keydef.concat(keydef, obj)
+	if getmetatable(obj)==Keydef.mt then
+		return tostring(keydef)..tostring(obj)
+	else
+		return tostring(keydef)..obj
+	end
+end
+Keydef.mt.__tostring=Keydef.tostring
+Keydef.mt.__concat=Keydef.concat
+
+Command = {}
+Command.mt = {} 
+function Command.new(keydef, func, help)
+	local command = {}
+	command.keydef = keydef
+	command.func = func
+	command.help = help
+	setmetatable(command, Command.mt)
+	return command
+end
+function Command.tostring(command)
+	return command.keydef..": "..command.help
+end	
+Command.mt.__tostring=Command.tostring
+
+
+Commands = {
+	map = {}
+}
+function Commands:add(keycode,modifier,keydescr,help,func)
+	local keydef = Keydef.new(keycode, modifier,keydescr)
+	self:_add_impl(keydef,help,func)
+end	
+function Commands:_add_impl(keydef,help,func,keygroup)
+	local command = self.map[keydef]
+	if command == nil then	
+		command = Command.new(keydef,func,help)	
+		self.map[keydef] = command
+	else
+		command.func = func
+		command.help = help
+		command.keygroup = keygroup
+	end
+end	
+function Commands:add_group(keygroup,keys,help,func)
+	for _k,keydef in pairs(keys) do
+		self:_add_impl(keydef,help,func,keygroup)
+	end
+end	
+function Commands:get(keycode,modifier)
+	return self.map[Keydef.new(keycode, modifier)]
+end
+function Commands:get_by_keydef(keydef)
+	return self.map[keydef]
+end
+function Commands:new(obj)
+	-- payload
+	local mt = {}
+	setmetatable(self.map,mt)
+	mt.__index=function (table, key)
+		return rawget(table,(key.modifier or "").."@#@"..(key.keycode or ""))
+	end	
+	mt.__newindex=function (table, key, value)
+		return rawset(table,(key.modifier or "").."@#@"..(key.keycode or ""),value)
+	end		
+	-- obj definition
+	obj = obj or {}
+	setmetatable(obj, self)
+	self.__index = self
+	return obj
+end