sequential erlang in 5 examples

shijiang1130

https://www.sics.se/~joe/talks/ll2_2002.pdf

1. Factorial

-module(math).
-export([fac/1]).

fac(N) when N > 0 -> N * fac(N-1);
fac(0)                   -> 1.

> math:fac(25).
15511210043330985984000000

shijiang1130

2- Binary Tree
lookup(Key,{Key,Val,_,_})-> {ok,Val};
lookup(Key,{Key1,Val,S,B}) when Key<Key1 -> lookup(Key,S);
lookup(Key,{key1,Val,S,B})-> lookup(Key,B);
lookup(Key,nil) -> not_found.

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3 - Append

append([H|T],L) -> [H|append(T,L)];
append([],L) -> L.

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4 - sort

sort([Pivot|T]) ->
      sort([X||X<-T,X<Pivot]) ++ [Pivot] ++ sort([X||X<-T,X>=Pivot]);
sort([]) -> [].

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5 - Adder

Adder = fun(N) -> fun(X) -> X + N end end.

#Fun

> G = Adder(10).

#Fun

>G(5).

15

flagcugb

很老的，很經(jīng)典的例子