test.txt

一个简单得词法分析器

program jcd;
Var x,y, g,m,a,b;
procedure swap;
var temp;
begin;
	  temp :=x;
      x := y;
      y := temp;
end; 
procedure mod;
  begin;
x := x - x/y *y;
end;
begin;
	read (x,y);
    a:=x;
    b:=y;
call mod;
while x <> 0 do;
	  begin;
        call swap;
        call mod;
     end;
     G :=y;
     m :=a*b/g;
     write(g,m);
@@@@;
end.;
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