// Match attempts to match the internal constant representations of x and y.
// If the attempt is successful, the result is the values of x and y,
// if necessary converted to have the same internal representation; otherwise
// the results are invalid.
func (x Const) Match(y Const) (u, v Const) {
switch a := x.val.(type) {
case bool:
if _, ok := y.val.(bool); ok {
u, v = x, y
}
case *big.Int:
switch y.val.(type) {
case *big.Int:
u, v = x, y
case *big.Rat:
var z big.Rat
z.SetInt(a)
u, v = Const{&z}, y
case cmplx:
var z big.Rat
z.SetInt(a)
u, v = Const{cmplx{&z, big.NewRat(0, 1)}}, y
}
case *big.Rat:
switch y.val.(type) {
case *big.Int:
v, u = y.Match(x)
case *big.Rat:
u, v = x, y
case cmplx:
u, v = Const{cmplx{a, big.NewRat(0, 0)}}, y
}
case cmplx:
switch y.val.(type) {
case *big.Int, *big.Rat:
v, u = y.Match(x)
case cmplx:
u, v = x, y
}
case string:
if _, ok := y.val.(string); ok {
u, v = x, y
}
default:
panic("unreachable")
}
return
}
