this.justAfterNull = checkNotNull(justAfterNull);
    }

    @Override
    public int compare(@Nullable String lhs, @Nullable String rhs) {
      if (lhs == rhs) {
        return 0;
      }
      if (lhs == null) {
        // lhs (null) comes just before justAfterNull.
        // If rhs is b, lhs comes first.
        if (rhs.equals(justAfterNull)) {
          return -1;
        }

	if arr, ok := rhs.ToArray(); ok {
		for _, element := range arr {
			// If we have an array we are on the wrong level.
			if cmp(element, *lhs) {
				return FromBool(true), nil
			}
		}
		return FromBool(false), nil
	}

	return FromBool(cmp(rhs, *lhs)), nil
}

func (e *Operand) evalNode(r Record, tableAlias string) (*Value, error) {
	lval, lerr := e.Left.evalNode(r, tableAlias)

				p.errorf("expected simple register reference")
			}
			a.Type = obj.TYPE_REG
			a.Reg = r1
			if r2 != 0 {
				// Form is R1:R2. It is on RHS and the second register
				// needs to go into the LHS.
				panic("cannot happen (Addr.Reg2)")
			}
		}
		// fmt.Printf("REG %s\n", obj.Dconv(&emptyProg, 0, a))
		p.expectOperandEnd()
		return
	}

	// Constant.
	haveConstant := false

(Y/Z)² = 1 + d(X/Z)²(Y/Z)² // (-X² + Y²)/Z² = 1 + (dX²Y²)/Z⁴ // (-X² + Y²)*Z² = Z⁴ + dX²Y² var lhs, rhs field.Element lhs.Subtract(&YY, &XX).Multiply(&lhs, &ZZ) rhs.Multiply(d, &XX).Multiply(&rhs, &YY).Add(&rhs, &ZZZZ) if lhs.Equal(&rhs) != 1 { t.Errorf("X, Y, and Z do not specify a point on the curve\nX = %v\nY = %v\nZ = %v", p.x, p.y, p.z) } // xy = T/Z lhs.Multiply(&p.x, &p.y) rhs.Multiply(&p.z, &p.t) if lhs.Equal(&rhs) != 1 { t.Errorf("point %d is not valid\nX = %v\nY = %v\nZ = %v", i, p.x, p.y, p.z)...

(Y/Z)² = 1 + d(X/Z)²(Y/Z)² // (-X² + Y²)/Z² = 1 + (dX²Y²)/Z⁴ // (-X² + Y²)*Z² = Z⁴ + dX²Y² var lhs, rhs field.Element lhs.Subtract(&YY, &XX).Multiply(&lhs, &ZZ) rhs.Multiply(d, &XX).Multiply(&rhs, &YY).Add(&rhs, &ZZZZ) if lhs.Equal(&rhs) != 1 { t.Errorf("X, Y, and Z do not specify a point on the curve\nX = %v\nY = %v\nZ = %v", p.x, p.y, p.z) } // xy = T/Z lhs.Multiply(&p.x, &p.y) rhs.Multiply(&p.z, &p.t) if lhs.Equal(&rhs) != 1 { t.Errorf("point %d is not valid\nX = %v\nY = %v\nZ = %v", i, p.x, p.y, p.z)...