Clojure language 1: Symbol

Symbol writing method:

1. It cannot start with a number.

2. It can be followed by text or numbers and *, + ,!, -,_,?

3./is a special character. It can only appear once in symbol. Generally, namespace is on the left. For example, my-namespace/Foo.

4 .. It is also a special character and can appear in symbol multiple times. For example, java. util. bitset.

5.: It can be used in symbol multiple times, but it cannot be continuous.

6. the symbol at the beginning or end is the symbol used by clojure itself. The symbol at the beginning or end is also the symbol used by clojure itself.

Clojure is a little different from general lisp, and there are the following differences in symbol:

1. Nil is not a symbol

2. the keyword (keyword) is not a symbol.

3. Unlike var, symbol is not a storage location.

For var reference my post: http://blog.csdn.net/sheismylife/article/details/8445916

As a basic description of the lisp language, other symbol can be found in another article:

Http://blog.csdn.net/sheismylife/article/details/7466413

You can use def to define a symbol, for example:

User => (def x 5) # 'user/x

The value of symbol X is 5, and the namespace is user.