stack_prim.cc

来自「标准的GP源代码,由Andy Singleton维护」· CC 代码 · 共 53 行

// stack_prim.cc
// W. Langdon cs.ucl.ac.uk
// version "$Revision: 1.2 $"

//Modifications (in reverse order)
//WBL 23 Oct 1995  New file


#include "pch.h"
#include "chrome.h"
#include "prob.h"
#include "stack_prim.h"

#ifdef FASTEVAL
	extern evalnode* IpGlobal;
	extern Chrome* ChromeGlobal;
#endif

int stack_pointer;
int max_pointer;
int stack_top;
retval* stack_data;

OPDEF(makenullEval) {max_pointer = 0;return stack_pointer=0;}

OPDEF(emptyEval){return (stack_pointer<=0)? 0: 1;}

OPDEF(topEval)  {return (stack_pointer<=0)? 0: stack_data[stack_pointer];}

OPDEF(popEval)  {return (stack_pointer<=0)? 0: stack_data[stack_pointer--];}

OPDEF(pushEval) {retval data = EVAL;
		 if(stack_pointer<stack_top) {
			 if(++stack_pointer>max_pointer)
				 max_pointer = stack_pointer;
			 return stack_data[stack_pointer] = data;
		 }
		 else
			 return 0;
	        }

void write_stack( ostream& fout )
{
fout<<" SP "<<stack_pointer<<endl;

for (int i = 1; i <= max_pointer; i++ ) {
	fout<<i<<":";
	if(i==stack_pointer) fout<<" <->";
	fout<<"\t"<<stack_data[i]<<endl;
}

};//end write_stack