Implement syntax sugar for maps

[Syndrome Dayna]

shared void asd()
{    
    value map = HashMap<String,Integer> {"A" -> 1};
 
    // Increment stored integer
    map.put("A", (map.get("A") else 0)+1); // <- Compiles, but not readable
    map["A"] += 1; // <- Readable, but doesnt compile          
}

[Lucas Werkmeister]

https://github.com/ceylon/ceylon/issues/4148

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[Syndrome Dayna]

This code does not satisfy the logic of language, because i didnt check for null.

map["A"] += 1; // <- Readable, but doesnt compile

Then I suggest another option:

// Increment stored integer
map.put("A", (map.get("A") else 0)+1); // <- not readable
map["A"] = (map["A"] else 0)+1; // <- readable

[Nikolay Tsankov]

What I miss is the compute() and merge() methods, but one can always do something like:

import ceylon.collection {

    HashMap    

}

class MyMap<Key, Item>() extends HashMap<Key, Item>() given Key satisfies Object {

    

    shared void compute(Key key, Item(Item?) fun) {

        put(key, fun(get(key)));

    }

    

    shared void merge(Key key, Item item, Item(Item) fun) {

        put(key, fun(get(key) else item));

    }

}

shared void run() {

   value map = MyMap<String, Integer>();

   map.compute("A", (x) => x else 0 + 1);

   map.merge("A", 0 , Integer.plus(1));

}