Programming-Idioms

# 28 Sort by a property
New implementation

Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating resource.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations 
with Ada.Containers.Vectors;
use Ada.Containers;
declare
   function Compare_Function (Left, Right : Item) return Boolean is (Left.P < Right.P);
   
   package Item_Vector_Sorting is new Item_Vectors.Generic_Sorting (Compare_Function);

   use Item_Vector_Sorting;
begin
   Sort (Items);
end;
#include <stdlib.h>
int compareProp (const void *a, const void *b)
{
    return (*(const Item**)a)->p - (*(const Item**)b)->p;
}

qsort(items, N, sizeof(Item*), compareProp);
(sort-by :p items)
#include <algorithm>
std::sort(begin(items), end(items), [](const auto& a, const auto& b) { return a.p < b.p; });
Array.Sort(items, (a, b) => compareFunc(a.p, b.p));
import std.algorithm.sorting;
sort!("a.p < b.p")(items);
items.sort((a, b) => Comparable.compare(a.p, b.p));
items.sort((a, b) => (a.p).compareTo(b.p));
Enum.sort_by(items, &(&1.p))
	
sort_by_birth(ListOfMaps) ->
  lists:sort(
    fun(A, B) ->
      maps:get(birth, A, undefined) =< maps:get(birth, B, undefined)
    end, ListOfMaps).

sort_by_birth(ListOfRecords) -> lists:keysort(#item.birth, ListOfRecords).
import "sort"
type ItemPSorter []Item
func (s ItemPSorter) Len() int{ return len(s) }
func (s ItemPSorter) Less(i,j int) bool{ return s[i].p<s[j].p }
func (s ItemPSorter) Swap(i,j int) { s[i],s[j] = s[j],s[i] }

func sortItems(items []Item){
	sorter := ItemPSorter(items)
	sort.Sort(sorter)
}
import "sort"
less := func(i, j int) bool {
	return items[i].p < items[j].p
}
sort.Slice(items, less)
items.sort { x, y -> x.p <=> y.p }
items.sort { x -> x.p }
import qualified Data.List as List
List.sortOn p items
sortBy (comparing p) items
items.sort(function(a,b) {
  return compareFieldP(a.p, b.p);
});
import java.util.Collections;
import java.util.Comparator;
Collections.sort(items, new Comparator<Item>(){
	@Override
	public int compare(Item a, Item b){
		return a.p - b.p;
	}
});
import java.util.Arrays;
import java.util.Comparator;
Arrays.sort(items, new Comparator<Item>(){
	public int compare(Item a, Item b){
		return a.p - b.p;
	}
});
import java.util.Comparator;
items.stream().sorted(Comparator.comparing(x -> x.p))
items.sortedBy { it.p }

(sort #'< items :key #'p)
table.sort(items, function(a,b)
	if a.p < b.p then return true end
end)
@import Foundation;
[items sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"p" ascending:YES]]]
function cmp($a, $b)
{
    if ($a->p == $b->p) {
        return 0;
    }

    return ($a->p < $b->p) ? -1 : 1;
}

usort($items, 'cmp');
uses fgl;
type

  TItem = class p: Integer; end;
  TItems = specialize TFPGObjectList<TItem>;

var items: TItems;

  function compare(const a, b: TItem): Integer;
  begin
    Result := a.p - b.p;
  end;

begin
  items := TItems.Create;
  // Add items here.
  items.Sort(@compare);
end.  
@items = sort { $a->{p} cmp $b->{p} } @items;
items = sorted(items, key=lambda x: x.p)
from operator import attrgetter
items = sorted(items, key=attrgetter('p'))
items.sort_by(&:p)
items.sort_by(|a,b|a.p.cmp(&b.p));
items.sort_by_key(|item| item.p);
case class S(x: Int)
val items = List(S(3), S(4), S(2))
items.sortBy( item: S => item.x )
items.sortBy(_.x)

Preview