order

Order

Fast, generic, concurrency-safe constructs for ordering anything.

Packages

compare

The package compare aims to bring a consistent implementation of a Less function for integers, floats and strings.

The problem with constraints.Ordered

With type parameters introduced in Go 1.18, a (currently experimental) package for the standard library has been proposed called constraints, which defines the following type constraint:

// Ordered is a constraint that permits any ordered type: any type that supports the operators < <= >= >.
// If future releases of Go add new ordered types, this constraint will be modified to include them.
type Ordered interface {
	Integer | Float | ~string
}

However, to actually order elements whose underlying type is constraints.Ordered, one must not rely upon the < operator alone. The standard library sort interface describes why:

// Note that floating-point comparison (the < operator on float32 or float64 values)
// is not a transitive ordering when not-a-number (NaN) values are involved.
// See Float64Slice.Less for a correct implementation for floating-point values.

This is what compare solves.

Introducing compare

This package provides a consistent interface for ordering these types, with corresponding implementations of LessFunc. To achieve this three type constraints have been defined:

• compare.SimpleOrdered
  Use this whenever you only care ordering integers or strings. The LessFunc defined for this type is just the < operator.
• compare.FloatOrdered
  Use this whenever you only care about ordering floating point types. The LessFunc defined for this type uses an IsNaN check to ensure a transitive ordering.
• compare.Ordered
  The union of the two above, and also a copy of constraints.Ordered. The LessFunc defined for this type uses an IsNaN check to ensure a transitive ordering. Use this for whenever you're using constraints.Ordered and you don't want to use the more constrained SimpleOrdered or FloatOrdered.

Along with the associated LessFuncs (respectively):

• LessSimple
• LessFloat
• Less

priorityqueue

See priorityqueue README.md.

chansort

See chansort README.md.

atomicbit

See atomicbit README.md.