108 lines
2.0 KiB
Go
108 lines
2.0 KiB
Go
package multiless
|
|
|
|
type (
|
|
// A helper for long chains of "less-than" comparisons, where later comparisons are only
|
|
// required if earlier ones haven't resolved the comparison.
|
|
Computation struct {
|
|
ok bool
|
|
less bool
|
|
}
|
|
)
|
|
|
|
func New() Computation {
|
|
return Computation{}
|
|
}
|
|
|
|
func (me Computation) EagerSameLess(same, less bool) Computation {
|
|
if me.ok || same {
|
|
return me
|
|
}
|
|
return Computation{
|
|
ok: true,
|
|
less: less,
|
|
}
|
|
}
|
|
|
|
func (me Computation) LazySameLess(lazy func() (same, less bool)) Computation {
|
|
if me.ok {
|
|
return me
|
|
}
|
|
same, less := lazy()
|
|
if !same {
|
|
me.less = less
|
|
}
|
|
return me
|
|
}
|
|
|
|
// Sorts so that false comes before true.
|
|
func (me Computation) Bool(l, r bool) Computation {
|
|
return me.EagerSameLess(l == r, r)
|
|
}
|
|
|
|
func (me Computation) Uint32(l, r uint32) Computation {
|
|
return me.EagerSameLess(l == r, l < r)
|
|
}
|
|
|
|
func (me Computation) Int64(l, r int64) Computation {
|
|
return me.EagerSameLess(l == r, l < r)
|
|
}
|
|
|
|
func (me Computation) Uint64(l, r uint64) Computation {
|
|
return me.EagerSameLess(l == r, l < r)
|
|
}
|
|
|
|
func (me Computation) Int(l, r int) Computation {
|
|
return me.EagerSameLess(l == r, l < r)
|
|
}
|
|
|
|
func (me Computation) CmpInt64(i int64) Computation {
|
|
return me.EagerSameLess(i == 0, i < 0)
|
|
}
|
|
|
|
func (me Computation) Cmp(i int) Computation {
|
|
return me.EagerSameLess(i == 0, i < 0)
|
|
}
|
|
|
|
func (me Computation) Uintptr(l, r uintptr) Computation {
|
|
return me.EagerSameLess(l == r, l < r)
|
|
}
|
|
|
|
func (me Computation) Less() bool {
|
|
return me.less
|
|
}
|
|
|
|
func (me Computation) Ok() bool {
|
|
return me.ok
|
|
}
|
|
|
|
func (me Computation) LessOk() (less, ok bool) {
|
|
return me.less, me.ok
|
|
}
|
|
|
|
func (me Computation) MustLess() bool {
|
|
less, ok := me.LessOk()
|
|
if !ok {
|
|
panic("computation has not differentiated yet")
|
|
}
|
|
return less
|
|
}
|
|
|
|
func (me Computation) Float64(l, r float64) Computation {
|
|
return me.EagerSameLess(l == r, l < r)
|
|
}
|
|
|
|
func (me Computation) Lazy(f func() Computation) Computation {
|
|
if me.ok {
|
|
return me
|
|
}
|
|
return f()
|
|
}
|
|
|
|
func (me Computation) AndThen(then Computation) Computation {
|
|
if me.ok {
|
|
return me
|
|
} else {
|
|
return then
|
|
}
|
|
}
|