「立己」：Ledge编程语言文档手册

• 在线文档: https://ledge-lang.github.io/zh/index.html
• Document Online: https://ledge-lang.github.io/en/index.html
• Markdown: https://github.com/ledge-lang/ledge-lang.github.io/blob/main/SUMMARY.md

介绍

Ledge(读音[ledʒ])编程语言是一个动态语言, 源代码文件扩展名.les，编译文件扩展名.lec, 中文名叫「立己」。

英文名来自于单词Knowledge，字母K的下一个字母是L，同时Ledge也是Knowledge的一部分，表示掌握知识的方法与过程。

中文名出自成语立己达人:

夫仁者，己欲立而立人，己欲达而达人。 ——《论语 · 雍也》

运行方式

$ ./ledge --help

Usge: ledge [option] ... [file | -] [arg] ...

Options and arguments (and corresponding environment variables):

-B        : disable write .lec files; also LEDGEWRITEBYTECODE=x
-engine   : 'vm' default
            'eval' is a ast-based interpreter
            'vm' is a stack-based virtual machine

file      : program read from script file
-         : program read from stdin (default; interactive mode if a tty)
arg ...   : arguments passed to program in sys.argv[1:]

-version  : version info

默认使用栈式虚拟机引擎vm，可以选择解释器引擎eval，或没有源代码文件提供，则进入交互模式。

交互模式

$ ./ledge
  _                   _
 | |                 | |
 | |        ___    __| |   __ _    ___
 | |       / _ \  / _` |  / _` |  / _ \
 | |____  |  __/ | (_| | | (_| | |  __/
 |______|  \___|  \__,_|  \__, |  \___|
                           __/ |
                          |___/

Hello lesliezhu! This is the Ledge programming language!
Version 0.0.4 by https://github.com/ledge-lang/
Feel free to type in commands, type `quit` to exit!
>> let add = lambda(x,y){ return x + y; }
Closure[0x600002d98e78]
>> add(3,4)
7
>> quit
Ledge, bye!

批处理模式

• run.les:

let a = 3.1 + 2;

print(a);

def fib(x){
    if(x == 0){
        return 0;
    } elif(x == 1){
        return 1;
    } else {
        return fib(x - 1) + fib(x - 2);
    }
}

print(fib);

let b = fib(5);

print(b);

• 运行源码文件(.les):

$ ./ledge run.les
Done: save compiled .lec file: run.lec
5.100000
Closure[0x600002324068]
5

• 运行字节码编译文件(.lec):

$ ./ledge run.lec
5.100000
Closure[0x6000038280b8]
5