Creating implementation for idiom 281 : Use a Point as a map key

Idiom

# 281 Use a Point as a map key

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You have a Point with integer coordinates x and y. Create a map m with key type Point (or equivalent) and value type string. Insert "Hello" at position (42, 5).

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import "dart:math";

Map<Point, String> m = {};
m[Point(42, 5)] = "Hello";

m := map[Point]string{}
p := Point{x: 42, y: 5}
m[p] = "Hello"

Demo
Doc

import qualified Data.Map.Strict as Map

type Point = (Integer, Integer)
m :: Map.Map Point String
m = Map.empty
m' = Map.insert (42, 5) "Hello" m

import java.util.HashMap;
import java.util.Map;

Map<Point, String> m = new HashMap<>();
m.put(new Point(42, 5), "Hello");

use strict;

my %m;
my $p = Point->new(x => 42, y => 5);

$m{$p} = 'Hello';

Demo
Doc

m = dict()
p = Point(x=42, y=5)
m[p] = 'Hello'

from collections import namedtuple

Point = namedtuple('Point', 'x y')

p = Point(42, 5)

m = {p: "Hello"}

Demo
Doc

m = {Point(42, 5): 'Hello'}

class Point:
    def __init__(self, x, y):
        self.x, self.y = x, y
    def __hash__(self):
        return hash((self.x, self.y))
    def __eq__(self, p):
        return self.x == p.x and \
               self.y == p.y
m = {Point(42, 5): 'Hello'}

Point = Struct.new(:x, :y)
m = {Point.new(42, 5) => "Hello"}

use std::collections::HashMap;

let mut map: HashMap<Point, String> = HashMap::new();
map.insert(Point { x: 42, y: 5 }, "Hello".into());

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