Properties with custom getters/setters in typescript only work in lua if accessed from a variable with the classes type. If accessed from a variable with an interface that maps to the class, the lua tries to access the property directly instead of calling the getter/setter.
Example:
interface Foo
{
prop: string;
}
class Bar
{
private _prop = "BAR";
public get prop() { return this._prop; }
public set prop(value: string) { this._prop = value; }
}
let bar = new Bar();
print(bar.prop);
let foo: Foo = bar;
print(foo.prop);Produces:
Bar = Bar or {}
Bar.__index = Bar
function Bar.new(construct, ...)
local instance = setmetatable({}, Bar)
instance._prop = "BAR"
if construct and Bar.constructor then Bar.constructor(instance, ...) end
return instance
end
function Bar.constructor(self)
end
function Bar.get__prop(self)
return self._prop
end
function Bar.set__prop(self,value)
self._prop = value;
end
local bar = Bar.new(true);
print(bar:get__prop()); --prints "BASE"
local foo = bar;
print(foo.prop); --prints nilOne possible solution would be to use a custom metatable for classes with properties like these:
Bar = Bar or {}
Bar__meta =
{
getters =
{
prop = function(self)
return self._prop
end
},
setters =
{
prop = function(self, value)
self._prop = value
end
},
__index = function(self, key)
local getter = Bar__meta.getters[key]
if getter then
return getter(self)
end
return rawget(self, key) or Bar[key]
end,
__newindex = function(self, key, value)
local setter = Bar__meta.setters[key]
if setter then
setter(self, value)
else
rawset(self, key, value)
end
end
}
function Bar.new(construct, ...)
local instance = setmetatable({}, Bar__meta)
instance._prop = "BAR"
if construct and Bar.constructor then Bar.constructor(instance, ...) end
return instance
end
function Bar.constructor(self)
end
local bar = Bar.new(true);
print(bar.prop);
local foo = bar;
print(foo.prop);BTW, sorry for all the bugs. I have a large lua project which would really benefit from static typing so I'm putting tstl through it's paces to see if it will work for what I need. :)
Properties with custom getters/setters in typescript only work in lua if accessed from a variable with the classes type. If accessed from a variable with an interface that maps to the class, the lua tries to access the property directly instead of calling the getter/setter.
Example:
Produces:
One possible solution would be to use a custom metatable for classes with properties like these:
BTW, sorry for all the bugs. I have a large lua project which would really benefit from static typing so I'm putting tstl through it's paces to see if it will work for what I need. :)