You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
37 lines
1.0 KiB
Lua
37 lines
1.0 KiB
Lua
local Observable = require "rx.observable"
|
|
local util = require "rx.util"
|
|
|
|
--- Returns an Observable that produces a specified number of elements from the end of a source
|
|
-- Observable.
|
|
-- @arg {number} count - The number of elements to produce.
|
|
-- @returns {Observable}
|
|
function Observable:takeLast(count)
|
|
if not count or type(count) ~= "number" then
|
|
error("Expected a number")
|
|
end
|
|
|
|
return Observable.create(function(observer)
|
|
local buffer = {}
|
|
|
|
local function onNext(...)
|
|
table.insert(buffer, util.pack(...))
|
|
if #buffer > count then
|
|
table.remove(buffer, 1)
|
|
end
|
|
end
|
|
|
|
local function onError(message)
|
|
return observer:onError(message)
|
|
end
|
|
|
|
local function onCompleted()
|
|
for i = 1, #buffer do
|
|
observer:onNext(util.unpack(buffer[i]))
|
|
end
|
|
return observer:onCompleted()
|
|
end
|
|
|
|
return self:subscribe(onNext, onError, onCompleted)
|
|
end)
|
|
end
|