main =doletx = [1..10] putStrLn"Our list is:"print(x) putStrLn"The last element of our list is:"print(last x) 它将产生以下输出 : Our list is:[1,2,3,4,5,6,7,8,9,10]The last element of our list is:10 初始化函数 初始化与尾部函数完全相反.它将列表作为参数并返回整个列表,而...
tell[]="This is a empty list"tell(x:[])="This list have only one element:"++show xtell(x:y:[])="This list have two elemtn: "++show x++" and "++show ytell(x:y:_)="This is a long list" ghci>tell []"This is a empty list"ghci>tell [3]"This list have only one eleme...
-- head and tail extract the first element and remaining elements, -- respectively, of a list, which must be non-empty. last and init -- are the dual functions working from the end of a finite list, -- rather than the beginning. head :: [a] -> a head (x:_) = x head [] =...
haskell中list and tuple 的基础函数总结 参考资料 :learnyouahaskell.comList: ++ :连接两个list (Haskell里list和string基本相同)ghci> [1,2...'s head.(抛去第一个元素)ghci> tail [5,4,3,2,1] [4,3,2,1] last takes a list and returns its last ...
EAN是标准条形码，目前商店里大多数商品上都打有此码，是世界通用的条形码。EAN13码是由前缀码、厂商...
我想您只是缺少了附加运算符++：我有一个if-else语句，在else块中，我希望它首先递归到函数，除了列表...
The type declaration of head states that it takes a list of any type and returns one element of that type. Although type variables can have names longer than one character, we usually give them names of a, b, c, d …Remember fst? It returns the first component of a pair. Let's ...
在线运⾏ main=do let x=[1..10] putStrLn Our list is: print (x) putStrLn The last element of our list is: print (last x) 它将产⽣以下输出- Our list is: [1,2,3,4,5,6,7,8,9,10] The last element of our list is: 10 初始函数 吾⽣也有涯,⽽知⽆涯 - ⽆涯教程...
build-tools can be specified as a list or a mapping.Examples:build-tools: - alex - happy:happy - hspec-discover == 2.*build-tools: alex: 3.2.* happy:happy: 1.19.* hspec-discover: 2.* When generating a .cabal file each element of build-tools is either added to build-tools or ...
-- match of __entire__ regex is first element, not first capture -- can also return Data.Array instead of List getAllSubmatches (a =~ b) :: [(Int, Int)] -- (index, length) λ> getAllSubmatches ("div[attr=1234]" =~ "div\\[([a-z]+)=([^]]+)\\]") :: [(Int, Int...