An warware: ma'auni

A cikin duniyar shirye-shirye masu aiki, ra'ayoyi sun samo asali daban-daban. Daga cikin su, 'yan kaɗan na iya zama kamar ba zato ba tsammani kuma suna da wuyar fahimta kamar wanda za mu ɓata a yau - Mai aiki. Amma da zarar kun fahimci ƙarfinsa da sassauƙarsa, masu aiki za su iya sauƙaƙe hanyoyin magance matsalolin shirye-shirye masu rikitarwa.

Fahimtar Ayyuka a Haskell

A functor, a cikin Haskell, shine nau'in da ke aiwatar da aikin Mai aiki nau'in nau'i. Da gaske wani abu ne da za a iya tsara shi. Functor ya ƙunshi abubuwa na farko guda biyu, aikin 'fmap' da wasu dokoki waɗanda ke tabbatar da daidaiton ɗabi'a.

Ana amfani da 'fmap' don amfani da aiki zuwa ƙima a cikin tsari ba tare da canza tsarin kansa ba. Wannan yana nufin, masu aiki suna ɗaukar mahallin aiwatar da ayyuka yayin da suke barin mahallin ba ya tasiri. Yana ba mu damar mai da hankali kan warware matsalolin ba tare da yin cudanya da mu'amala da mahallin ba.

instance Functor Maybe where
    fmap func (Just x) = Just (func x)
    fmap func Nothing = Nothing

Dokokin Functor

Don nau'in don cancanta a matsayin mai aiki, dole ne ya cika dokoki biyu da aka sani da Dokokin Ayyuka. Waɗannan dokokin suna kiyaye amincin tsarin da muke aiki akai.

Doka 1: Taswirar aikin ainihi akan mai aiki yakamata ya dawo da ainihin ma'aikaci - fmap = id

fmap id (Just 3)  -- Returns: Just 3
fmap id Nothing  -- Returns: Nothing

Doka ta 2: Haɗa ayyuka guda biyu sannan taswirar aikin da aka samu akan ma'aikaci ya zama iri ɗaya da fara taswirar aiki ɗaya sannan taswirar wani - fmap (f . g) == fmap f . fmap g

fmap (abs . negate) (Just 5)  -- Returns: Just 5
(fmap abs . fmap negate) (Just 5)  -- Returns: Just 5

Aiwatar da Ayyuka don Magance Matsaloli

Yanzu, bari mu kwatanta yadda Functors za su iya magance matsaloli yadda ya kamata. Misali, ka ce muna da jerin yuwuwar sakamako a matsayin jerin ƙima. Idan muna son haɓaka kowane ɗayan, a al'ada, dole ne mu rubuta lambar tukunyar jirgi da yawa. Shigar da Ayyuka.

'fmap' na iya yin jujjuya lissafin cikin sauƙi, ba tare da ƙetare ƙimar komai ba da amfani da aiki kawai zuwa ƙima. Duk yayin da yake riƙe ainihin tsari.

let maybes = [Just 1, Nothing, Just 3]
fmap (+1) <$> maybes  -- Returns: [Just 2, Nothing, Just 4]

Don haka, masu aiki suna ba da ingantacciyar hanya, mai hankali don sarrafa ƙididdiga a cikin mahallin. Suna samar da wani muhimmin sashi na ikon Haskell don gudanar da ayyuka masu rikitarwa tare da sauƙi, ƙayatacciyar lamba.