sortby.go

package sliceP

import "github.com/clipperhouse/typewriter"

var sortBy = &typewriter.Template{
	Name: "SortBy",
	Text: `
// SortBy returns a new ordered {{.SliceName}}, determined by a func defining ‘less’. See: http://clipperhouse.github.io/gen/#SortBy
func (rcv {{.SliceName}}) SortBy(less func({{.Type}}, {{.Type}}) bool) {{.SliceName}} {
	result := make({{.SliceName}}, len(rcv))
	copy(result, rcv)
	// Switch to heapsort if depth of 2*ceil(lg(n+1)) is reached.
	n := len(result)
	maxDepth := 0
	for i := n; i > 0; i >>= 1 {
		maxDepth++
	}
	maxDepth *= 2
	quickSort{{.SliceName}}(result, less, 0, n, maxDepth)
	return result
}
`}

var isSortedBy = &typewriter.Template{
	Name: "IsSortedBy",
	Text: `
// IsSortedBy reports whether an instance of {{.SliceName}} is sorted, using the pass func to define ‘less’. See: http://clipperhouse.github.io/gen/#SortBy
func (rcv {{.SliceName}}) IsSortedBy(less func({{.Type}}, {{.Type}}) bool) bool {
	n := len(rcv)
	for i := n - 1; i > 0; i-- {
		if less(rcv[i], rcv[i-1]) {
			return false
		}
	}
	return true
}
`}

var sortByDesc = &typewriter.Template{
	Name: "SortByDesc",
	Text: `
// SortByDesc returns a new, descending-ordered {{.SliceName}}, determined by a func defining ‘less’. See: http://clipperhouse.github.io/gen/#SortBy
func (rcv {{.SliceName}}) SortByDesc(less func({{.Type}}, {{.Type}}) bool) {{.SliceName}} {
	greater := func(a, b {{.Type}}) bool {
		return less(b, a)
	}
	return rcv.SortBy(greater)
}
`}

var isSortedByDesc = &typewriter.Template{
	Name: "IsSortedByDesc",
	Text: `
// IsSortedDesc reports whether an instance of {{.SliceName}} is sorted in descending order, using the pass func to define ‘less’. See: http://clipperhouse.github.io/gen/#SortBy
func (rcv {{.SliceName}}) IsSortedByDesc(less func({{.Type}}, {{.Type}}) bool) bool {
	greater := func(a, b {{.Type}}) bool {
		return less(b, a)
	}
	return rcv.IsSortedBy(greater)
}
`}