erlang - 16#00 是什么意思？

Question

看看这个erlang file中的代码有一个这样的函数:

socket_type_atom(16#00) ->      pair;
socket_type_atom(16#01) ->      pub;
socket_type_atom(16#02) ->      sub;
socket_type_atom(16#03) ->      req;
socket_type_atom(16#04) ->      rep;
socket_type_atom(16#05) ->      dealer;
socket_type_atom(16#06) ->      router;
socket_type_atom(16#07) ->      pull;
socket_type_atom(16#08) ->      push.

根据我对 erlang 整数表示法的理解，5#10 表示以 10 为基数的整数 5。那么 16#00 代表什么？

Answer 1

如 documentation 中所述:

There are two types of numeric literals, integers and floats. Besides the conventional notation, there are two Erlang-specific notations:

$char
ASCII value or unicode code-point of the character char.

base#value
Integer with the base base, that must be an integer in the range 2..36.
In Erlang 5.2/OTP R9B and earlier versions, the allowed range is 2..16.

因此，16#number 只是十六进制的number。例如:

1> 16#10 == 16.
true

或二进制:

2> 2#11111111.
255