plx程序结构.txt

pl/x的编译器

/------------------------------------------------\
| program                                        |
--------------------------------------------------
| //变量定义(可有可无)                           |
--------------------------------------------------
| begin                                          |
--------------------------------------------------
| //函数定义(可有可无)                           |
--------------------------------------------------
| //程序体即语句序列(可有可无)                   |
--------------------------------------------------
| end.                                           |
\------------------------------------------------/

example:
-------------------------------------------------
program  //jjjj
//变量定义（可有可无）

begin

//函数定义(可有可无)

procedure my (integer i,j)
logical b2,b3
begin
	procedure myy (integer i,j)  //嵌套定义
	logical b2,b3
	begin

	end
end

procedure mry (integer i,j)     //平行定义
logical b2,b3
begin

end

//语句

call my 1 i;  //函数调用语句
call myy 1 3

end.
--------------------------------------------------
//-------------if语句--------------------\
//if b1 then                             |
//	 a1:=4;                          |
//	 else                            |
//	 a2:=5;                          |
//	 if b1 then                      |
//		a1:=a1+a2                |
//	 else                            |
//		a1:=a1-a2                |
//	 end                             |
//end                                    |
//---------------------------------------/

//-------------repeat语句----------------\
//                                       |
//repeat                                 |
//	a1:=a2                           |
//until                                  |
//	b1                               |
//---------------------------------------/

//-------------write语句-----------------\
//write a1+a2-4                          |
//---------------------------------------/

//-------------read语句------------------\
//read a1                                |
//---------------------------------------/

//-------------while语句-----------------\
//while a1=3                             |
//do                                     |
//a2:=a1;                                |
//a1:=a1-1                               |
//end;                                   |
//---------------------------------------/

//------------函数-----------------------\
//procedure my(integer a1,a2)            |
//integer a3                             |
//begin                                  |
//	procedure myy(integer a5,a6)     |
//	integer a4                       |
//	begin                            |
//		a4:=a1+a2                |
//	end                              |
//                                       |
//	a3:=a1+a2                        |
//end                                    |
//                                       |
//call my 1 3                            |
//---------------------------------------/

//-------------for语句 ------------------\
//for a1 from 1 to 6                     |
//do                                     |
//read a2;                               |
//write a2                               |
//end                                    |
//---------------------------------------/