kandi background
kandi background
Explore Kits
kandi background
Explore Kits
kandi background
Explore Kits
kandi background
Explore Kits
Explore all FTP open source software, libraries, packages, source code, cloud functions and APIs.

Popular New Releases in FTP

7.82.0

v2.2.2

v3.0.5965.2771

webMAN MOD 1.47.40

curl

7.82.0

sftpgo

v2.2.2

FarManager

v3.0.5965.2771

webMAN-MOD

webMAN MOD 1.47.40

nging

Popular Libraries in FTP

Trending New libraries in FTP

Top Authors in FTP

1

4 Libraries

40

2

4 Libraries

189

3

4 Libraries

60

4

4 Libraries

78

5

3 Libraries

7

6

3 Libraries

9

7

3 Libraries

20

8

3 Libraries

780

9

3 Libraries

12

10

3 Libraries

27

1

4 Libraries

40

2

4 Libraries

189

3

4 Libraries

60

4

4 Libraries

78

5

3 Libraries

7

6

3 Libraries

9

7

3 Libraries

20

8

3 Libraries

780

9

3 Libraries

12

10

3 Libraries

27

Trending Kits in FTP

php-ftp

10 Best PHP FTP

One of the most common tasks in web development is transferring files and folders to and from a server. PHP provides a number of FTP libraries that make this task easy. PHP supports FTP (File Transfer Protocol) with the help of an FTP library. OpenMediaVault is a free Linux distribution designed to run Network Attached Storage (NAS) systems. It's based on Debian and is freely available under a GPLv2 license. One of the best things about OpenMediaVault is its user interface which makes it easy to set up and manage your networked storage devices. TinUFileManager is an easy-to-use file manager for your PHP web applications. It supports multiple languages like Spanish, Catalan, Portuguese, French, German, and more! This library also comes with an authentication system which makes it easy to manage users/groups and their permissions through a simple interface. The PHP FTP Client library provides an easy way to connect to any FTP server from within your PHP scripts without having to worry about writing complex code or dealing with any low-level sockets yourself! Developers tend to use some of the following open source PHP FTP libraries are given below

Trending Discussions on FTP

    Stateful generators with Haskell pipes
    Uploading a file to testcontainer FTP server fails with Connection refused after being connected
    Can't install Python 3.10.0 with pyenv on MacOS
    Unable to install pgAdmin 4 in ubuntu 21.10
    "The format of the URI could not be determined" when combining absolute and relative URLs in C#
    Compiling python 3.10 at Amazon Linux 2
    Adding imagemagick into my php 7.4 docker raised error
    Need understanding as to why string.StartsWith() is true when it should be false
    How can I add values from the first column to a new array?
    Debian 11 Update broke samueldebruyn/debian-git?

QUESTION

Stateful generators with Haskell pipes

Asked 2022-Mar-31 at 18:32
  1. Suppose I want to model, using Haskell pipes, a Python Generator[int, None, None] which keeps some internal state. Should I be using Producer int (State s) () or StateT s (Producer int m) (), where m is whatever type of effect I eventually want from the consumer?

  2. How should I think about the notion of transducers in pipes? So in Oleg's simple generators, there is

1type Transducer m1 m2 e1 e2  = Producer m1 e1 -> Producer m2 e2
2

but I don't know what the analog is in pipes, because any Proxy objects that interact seem to rely on the same underlying monad m, not switching from m1 to m2. See the Prelude functions, for instance.

I think I'm just misunderstanding something fundamental about the way pipes works. Thanks for your help.

ANSWER

Answered 2022-Mar-31 at 18:32

In pipes, you typically wouldn't use effects in the base monad m of your overall Effect to model the internal state of a Producer. If you really wanted to use State for this purpose, it would be an internal implementation detail of the Producer in question (discharged by a runStateP or evalStateP inside the Producer, as explained below), and the State would not appear in the Producer's type.

It's also important to emphasize that a Producer, even when it's operating in the Identity base monad without any "effects" at its disposal, isn't some sort of pure function that would keep producing the same value over and over without monadic help. A Producer is basically a stream, and it can maintain state using the usual functional mechanisms (e.g., recursion, for one). So, you definitely don't need a State for a Producer to be stateful.

The upshot is that the usual model of a Python Generator[int, None, None] in Pipes is just a Monad m => Producer Int m () polymorphic in an unspecified base monad m. Only if the Producer needs some external effects (e.g., IO to access the filesystem) would you require more of m (e.g., a MonadIO m constraint or something).

To give you a concrete example, a Producer that generates pseudorandom numbers obviously has "state", but a typical implementation would be a "pure" Producer:

copy icondownload icon

1type Transducer m1 m2 e1 e2  = Producer m1 e1 -> Producer m2 e2
2randoms :: (Monad m) => Word32 -> Producer Int m ()
3randoms seed = do
4  let seed' = 1664525 * seed + 1013904223
5  yield $ fromIntegral seed'
6  randoms seed'
7

with the state maintained via recursion.

If you really decided to maintain this state via the State monad, the type of the Producer wouldn't change. You'd just use a State internally. The Pipes.Lift module provides some helpers (like evalStateP used here) to locally add a monad layer to facilitate this:

copy icondownload icon

1type Transducer m1 m2 e1 e2  = Producer m1 e1 -> Producer m2 e2
2randoms :: (Monad m) => Word32 -> Producer Int m ()
3randoms seed = do
4  let seed' = 1664525 * seed + 1013904223
5  yield $ fromIntegral seed'
6  randoms seed'
7randoms' :: (Monad m) => Word32 -> Producer Int m ()
8randoms' seed = evalStateP seed $ forever $ do
9  x <- get
10  let x' = 1664525 * x + 1013904223
11  yield $ fromIntegral x'
12  put x'
13

Oleg's simple generators are entirely different. His producers and consumers produce and consume values only through monadic effects, and "monad changing" is central to the implementation. In particular, I believe his consumers and transducers can only maintain state via a monadic effect, like a State monad, though I'd have to look a little more carefully to be sure.

In contrast, pipes proxies can produce and consume values and maintain internal state independent of the underlying base monad.

Ultimately, the analog of Oleg's transducers in pipes are simply the Pipes. Both consume values from a producer and yield values to a consumer. The monad changing in Oleg's transducers is just an implementation detail.

Source https://stackoverflow.com/questions/71686259

Community Discussions contain sources that include Stack Exchange Network

    Stateful generators with Haskell pipes
    Uploading a file to testcontainer FTP server fails with Connection refused after being connected