example.ast

一个编译器修改的例子

(*
    Example asterix source for exercise 1.

	Compile using:

    cbc example.ast
    ./a.out
    should result in:
	   ~
	   Hello (1) ?
	   Hello (2) ?
	   Hello (3) ?
           Hello (4) ?
*)

include io.inc


var zz : int;

function foo(a, b, c: int) : int is
begin	
	if (a = 0) then return a;
	return foo(a - 1, b + 1, c);
end

function bar() : int  is return 1;

function zoo() : array of array of int is 
return new array[1] of array of int;

function main(argv: array of string): int is
var
        a, b, c, d, e: int;
        g : array of array of char;
begin
	g := new array[bar()] of array of char;

	a := 1;

	if  false and true or true and false then
	    WriteString("?\n");
        else if false then if false then 
	     WriteString("!\n");
	else if true then
	     WriteString("#\n");
	else WriteString("@\n");
	else WriteString("~\n");

	repeat begin    
	   WriteString("Hello (1) ?\n");
	   while (a > 0) do 
		    a := foo(100, 50, a);
	   WriteString("Hello (2) ?\n");	    
	end until (a = 0);

	WriteString("Hello (3) ?\n");

	if (a = size of zoo() ) then begin end
           
	WriteString("Hello (4) ?\n");

 	  
        zz := 2;
        e := 3;
        b := 4;
        c := 5;      
        d := 6;


	zz := 1;

        if (a + b + c - d / zz * e = 0) then begin end

	return 0;

end