phielimValue(phi)
}

// LackingPos indicates whether b is a block whose position should be inherited
// from its successors.  This is true if all the values within it have unreliable positions
// and if it is "plain", meaning that there is no control flow that is also very likely
// to correspond to a well-understood source position.
func (b *Block) LackingPos() bool {

			return x
		}
	case constant.String:
		return constant.StringVal(val)
	}
	return nil
}

// A valueMap maps a case value (of a basic Go type) to a list of positions
// where the same case value appeared, together with the corresponding case
// types.
// Since two case values may have the same "underlying" value but different

}

// seenPos2 tracks whether we have seen a token.Position pair.
var seenPos2 = make(map[pos2]bool)

// dedup takes a token.Position pair and returns a pair that does not
// duplicate any existing pair. The returned pair will have the Offset
// fields cleared.
func dedup(p1, p2 token.Position) (r1, r2 token.Position) {
	key := pos2{
		p1: p1,
		p2: p2,
	}

   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,
   * and ABSENT for empty positions.  We then look up the keys in alternatingKeysAndValues.
   *
   * (The index actually stored is the index of the key in alternatingKeysAndValues, which is

		x.typ = Typ[Bool]
		x.val = constant.MakeBool(true)
		// TODO(gri) should have a better position here
		pos := s.Rbrace
		if len(s.Body) > 0 {
			pos = s.Body[0].Pos()
		}
		x.expr = syntax.NewName(pos, "true")
	}

	check.multipleSwitchDefaults(s.Body)

	seen := make(valueMap) // map of seen case values to positions and types
	for i, clause := range s.Body {
		if clause == nil {

		t.Errorf("test %q, lookup %q (n = %d): expected %d results; got %d", tc.name, s, n, len(exp), len(res))
	}

	// if n >= 0 the number of results is limited --- unless n >= all results,
	// we may obtain different positions from the Index and from find (because
	// Index may not find the results in the same order as find) => in general
	// we cannot simply check that the res and exp lists are equal

	//   - 'set': `X + Y` performs a union where the array positions of all elements in `X` are preserved and
	//     non-intersecting elements in `Y` are appended, retaining their partial order.
	//   - 'map': `X + Y` performs a merge where the array positions of all keys in `X` are preserved but the values

                int separatorLength = separator.length();

                positions:
                for (int p = start, last = toSplit.length() - separatorLength; p <= last; p++) {
                  for (int i = 0; i < separatorLength; i++) {
                    if (toSplit.charAt(i + p) != separator.charAt(i)) {
                      continue positions;
                    }
                  }
                  return p;

	c.s[len(c.s)-1].st = pos
	c.setLast(pos)
	return nil
}

// Kill method should be invoked on instruction at position p if instr
// should be treated as as having a kill (lifetime end) for the
// resource. See the example in the comment at the beginning of this
// file for an example. Note that if we see a kill at position K for a
// resource currently live since J, this will result in a lifetime

                int separatorLength = separator.length();

                positions:
                for (int p = start, last = toSplit.length() - separatorLength; p <= last; p++) {
                  for (int i = 0; i < separatorLength; i++) {
                    if (toSplit.charAt(i + p) != separator.charAt(i)) {
                      continue positions;
                    }
                  }
                  return p;