package org.jabref.logic.bst;
import java.util.Stack;
import org.jabref.logic.bst.VM.BstEntry;
import org.jabref.logic.bst.VM.BstFunction;
/**
*
* The |built_in| function {\.{purify\$}} pops the top (string) literal, removes
* nonalphanumeric characters except for |white_space| and |sep_char| characters
* (these get converted to a |space|) and removes certain alphabetic characters
* contained in the control sequences associated with a special character, and
* pushes the resulting string. If the literal isn't a string, it complains and
* pushes the null string.
*
*/
public class PurifyFunction implements BstFunction {
private final VM vm;
public PurifyFunction(VM vm) {
this.vm = vm;
}
@Override
public void execute(BstEntry context) {
Stack<Object> stack = vm.getStack();
if (stack.isEmpty()) {
throw new VMException("Not enough operands on stack for operation purify$");
}
Object o1 = stack.pop();
if (!(o1 instanceof String)) {
vm.warn("A string is needed for purify$");
stack.push("");
return;
}
stack.push(BibtexPurify.purify((String) o1, vm));
}
}