Skip to content
Snippets Groups Projects
Select Git revision
21 results Searching

Stack.pmod

Blame
  • Stack.pmod 882 B
    #define error(X) throw( ({ (X), backtrace()[0..sizeof(backtrace())-2] }) )
    
    class stack {
      int ptr;
      mixed *arr=allocate(32);
    
      void push(mixed val)
      {
        if(ptr==sizeof(arr)) arr+=allocate(ptr);
        arr[ptr++]=val;
      }
    
      mixed top()
      {
        if (ptr) {
          return(arr[ptr-1]);
        }
        error("Stack underflow\n");
      }
    
      mixed pop(void|int val)
      {
        mixed foo;
    
        if (val) {
          if (ptr <= 0) {
    	error("Stack underflow\n");
          }
    
          if (ptr < val) {
            val = ptr;
          }
          ptr -= val;
          foo = arr[ptr..ptr + val - 1];
     
          for (int i=0; i < val; i++) {
            arr[ptr + i] = 0;       /* Don't waste references */
          }
        } else {
          if(--ptr < 0)
    	error("Stack underflow\n");
        
          foo=arr[ptr];
          arr[ptr]=0; /* Don't waste references */
        }
        return foo;
      }
    
      void reset()
      {
        arr=allocate(32);
        ptr=0;
      }
    };