package org.basex.query.func.hof;

import org.basex.query.*;
import org.basex.query.expr.*;
import org.basex.query.func.*;
import org.basex.query.value.*;
import org.basex.query.value.item.*;
import org.basex.query.value.type.*;

/**
 * Function implementation.
 *
 * @author BaseX Team 2005-22, BSD License
 * @author Leo Woerteler
 */
public final class HofUntil extends StandardFunc {
  @Override
  public Value value(final QueryContext qc) throws QueryException {
    final FItem pred = checkArity(exprs[0], 1, qc), func = checkArity(exprs[1], 1, qc);
    Value value = exprs[2].value(qc);

    while(!toBoolean(pred.invoke(qc, info, value).item(qc, info))) {
      value = func.invoke(qc, info, value);
    }
    return value;
  }

  @Override
  protected Expr opt(final CompileContext cc) {
    final Expr expr2 = exprs[1], expr3 = exprs[2];
    final FuncType ft = expr2.funcType();
    if(ft != null) {
      final SeqType st = ft.declType.intersect(expr3.seqType());
      if(st != null) exprType.assign(st);
    }
    return this;
  }
}
