Class MapConstraint<K, V>

Note: the preferred way to create a map constraint is with cjs({...}) or cjs.map(options).

Emulates a JavaScript object (or Map), but with constraints. Its entries are ordered, and its keys can be anything (compared with === unless an equals option is given).

Example

var map = cjs({ x: 1 });
    var x_plus_one = cjs(function() { return map.get("x") + 1; });
    x_plus_one.get(); // 2
    map.put("x", 10);
    x_plus_one.get(); // 11

Type Parameters

K = any
V = any

Index

Constructors

constructor

Properties

BREAK

Constructors

constructor

new MapConstraint<K = any, V = any>(
options?: MapConstraintOptions<K, V>,
): MapConstraint<K, V>
Type Parameters
- K = any
- V = any
Parameters
- Optionaloptions: MapConstraintOptions<K, V>
Returns MapConstraint<K, V>
- Defined in map-constraint.ts:90

Properties

`Static` `Readonly`BREAK

BREAK: object = BREAK

Return this from a forEach callback to stop iterating.

Methods

clear

clear(silent?: boolean): this
Removes every entry.
Parameters
- Optionalsilent: boolean
  If true, don't invalidate the constraints that depended on the entries
Returns this
Example
```
var map = cjs({x: 1, y: 2});
    map.clear();
    map.isEmpty(); // true
```
- Defined in map-constraint.ts:311

destroy

destroy(silent?: boolean): void
Clears this map and cleans up its constraints.
Parameters
- Optionalsilent: boolean
  If true, don't invalidate the constraints that depended on it
Returns void
- Defined in map-constraint.ts:497

entries

entries(): { key: K; value: V }[]
Every entry, in order, as {key, value} objects.

Returns { key: K; value: V }[]
Example
```
var map = cjs({x: 1, y: 2});
    map.entries(); // [{key:'x',value:1}, {key:'y',value:2}]
```
- Defined in map-constraint.ts:181

forEach

forEach(
callback: (this: any, value: V, key: K, index: number) => unknown,
thisArg?: unknown,
): this
Calls callback with the value, key, and index of every entry, in order. Return cjs.MapConstraint.BREAK from it to stop.
Parameters
- callback: (this: any, value: V, key: K, index: number) => unknown
- thisArg: unknown = ...
  The this for callback (default: this map constraint)
Returns this
Example
```
var map = cjs({x:1,y:2,z:3});
    map.forEach(function(val, key) {
        console.log(key+':'+val);
        if(key === 'y') {
            return cjs.MapConstraint.BREAK;
        }
    }); // x:1 ... y:2
```
- Defined in map-constraint.ts:338

get

get(key: K): V | undefined
The value for key (like this[key]), or undefined.
Parameters
- key: K
Returns V | undefined
Example
```
var map = cjs({x: 1, y: 2});
    map.get("x"); // 1
```
- Defined in map-constraint.ts:259

getOrPut

getOrPut(
    key: K,
    create: (this: any, key: K) => V,
    context?: unknown,
    index?: number,
    literal?: boolean,
): V
The value for key; if there isn't one, sets it to create(key) first.
Parameters
- key: K
- create: (this: any, key: K) => V
- Optionalcontext: unknown
  The this for create (default: this map constraint)
- Optionalindex: number
  Where to put a new entry (default: at the end)
- Optionalliteral: boolean
  For a new entry, whether to treat a function value as the value itself
Returns V
Example
```
var map = cjs({x: 1, y: 2});
    map.getOrPut('z', function() {
        console.log("evaluating");
        return 3;
    }); // output: 'evaluating'
    // 3
    map.getOrPut('z', function() {
        console.log("evaluating");
        return 3;
    }); // (no output)
    // 3
```
- Defined in map-constraint.ts:415

has

has(key: K): boolean
Whether there is an entry for key.
Parameters
- key: K
Returns boolean
Example
```
var map = cjs({x: 1, y: 2});
    map.has('x'); // true
```
- Defined in map-constraint.ts:433

indexOf

indexOf(key: K): number
The index of the entry for key, or -1.
Parameters
- key: K
Returns number
Example
```
var map = cjs({x: 1, y: 2});
    map.indexOf('y'); // 1
    map.indexOf('z'); // -1
```
- Defined in map-constraint.ts:387

isEmpty

isEmpty(): boolean
Whether there are no entries.

Returns boolean
Example
```
var map = cjs({x: 1, y: 2});
    map.isEmpty(); // false
```
- Defined in map-constraint.ts:203

item

item(): Record<string, V>
With no arguments: a plain object of the entries (see toObject). With key: the value for key. With key and value (and optionally index): sets the value for key (see put).

Returns Record<string, V>
Example
```
var map = cjs({x: 1, y: 2});
    map.item();       // {x:1,y:2}
    map.item('x');    // 1
    map.item('z', 3);
    map.keys();       // ['x','y','z']
```
- Defined in map-constraint.ts:278
item(key: K): V | undefined
With no arguments: a plain object of the entries (see toObject). With key: the value for key. With key and value (and optionally index): sets the value for key (see put).
Parameters
- key: K
Returns V | undefined
Example
```
var map = cjs({x: 1, y: 2});
    map.item();       // {x:1,y:2}
    map.item('x');    // 1
    map.item('z', 3);
    map.keys();       // ['x','y','z']
```
- Defined in map-constraint.ts:279
item(key: K, value: V, index?: number): this
With no arguments: a plain object of the entries (see toObject). With key: the value for key. With key and value (and optionally index): sets the value for key (see put).
Parameters
- key: K
- value: V
- Optionalindex: number
Returns this
Example
```
var map = cjs({x: 1, y: 2});
    map.item();       // {x:1,y:2}
    map.item('x');    // 1
    map.item('z', 3);
    map.keys();       // ['x','y','z']
```
- Defined in map-constraint.ts:280

itemConstraint

itemConstraint(key: K | Constraint<K>): Constraint<V | undefined>
A constraint whose value is the value for key (which can itself be a constraint).
Parameters
- key: K | Constraint<K>
Returns Constraint<V | undefined>
Example
```
var map = cjs({x: 1, y: 2});
    var x_val = map.itemConstraint('x');
    x_val.get(); // 1
    map.item('x', 3);
    x_val.get(); // 3
```
- Defined in map-constraint.ts:297

keyForValue

keyForValue(value: V, equalityCheck?: EqualityCheck<V>): K | undefined
The key of an entry whose value is value (or undefined).
Parameters
- value: V
- OptionalequalityCheck: EqualityCheck<V>
  How to compare values (default: this map's value equality check)
Returns K | undefined
Example
```
var map = cjs({x: 1, y: 2, z: 3});
    map.keyForValue(1); // 'x'
```
- Defined in map-constraint.ts:477

keys

keys(): K[]
The keys, in order.

Returns K[]
Example
```
var map = cjs({x: 1, y: 2});
    map.keys(); // ['x','y']
```
- Defined in map-constraint.ts:159

move

move(key: K, index: number): this
Moves the entry for key to index.
Parameters
- key: K
- index: number
Returns this
Example
```
var map = cjs({x: 1, y: 2, z: 3});
    map.move('z', 0);
    map.keys(); // ['z','x','y']
```
- Defined in map-constraint.ts:462

moveIndex

moveIndex(oldIndex: number, newIndex: number): this
Moves the entry at oldIndex to newIndex.
Parameters
- oldIndex: number
- newIndex: number
Returns this
Example
```
var map = cjs({x: 1, y: 2, z: 3});
    map.moveIndex(1, 0);
    map.keys(); // ['y','x','z']
```
- Defined in map-constraint.ts:449

put

put(key: K, value: V, index?: number, literal?: boolean): this
Sets the value for key (like this[key] = value).
Parameters
- key: K
- value: V
- Optionalindex: number
  Where to put the entry (default: at the end for a new key; unchanged for an existing one)
- Optionalliteral: boolean
  For a new key, whether to treat a function value as the value itself
Returns this
Example
```
var map = cjs({x: 1, y: 2});
    map.put("z", 3, 1);
    map.keys(); // ['x','z','y']
```
- Defined in map-constraint.ts:218

remove

remove(key: K, silent?: boolean): this
Removes the entry for key (like delete this[key]).
Parameters
- key: K
- Optionalsilent: boolean
  If true, don't invalidate the constraints that depended on the entry
Returns this
Example
```
var map = cjs({x: 1, y: 2});
    map.remove("x");
    map.keys(); // ['y']
```
- Defined in map-constraint.ts:237

setEqualityCheck

setEqualityCheck(equalityCheck: EqualityCheck<K>): this
Change how keys are compared.
Parameters
- equalityCheck: EqualityCheck<K>
Returns this
- Defined in map-constraint.ts:349

setHash

setHash(hash: HashOption<K>): this
Change how keys are hashed: a function, or the name of a method to call on each key.
Parameters
- hash: HashOption<K>
Returns this
- Defined in map-constraint.ts:361

setValueEqualityCheck

setValueEqualityCheck(equalityCheck: EqualityCheck<V>): this
Change how values are compared (for keyForValue).
Parameters
- equalityCheck: EqualityCheck<V>
Returns this
- Defined in map-constraint.ts:355

setValueHash

setValueHash(hash: boolean | HashOption<V>): this
Change how values are hashed (see the valuehash option); false turns value hashing off.
Parameters
- hash: boolean | HashOption<V>
Returns this
- Defined in map-constraint.ts:370

size

size(): number
The number of entries.

Returns number
Example
```
var map = cjs({x: 1, y: 2});
    map.size(); // 2
```
- Defined in map-constraint.ts:192

toObject

toObject(keyMap?: (key: K) => PropertyKey): Record<string, V>
A plain object with this map's entries.
Parameters
- keyMap: (key: K) => PropertyKey = ...
  Converts each key to a property name (default: the key itself)
Returns Record<string, V>
Example
```
var map = cjs({x: 1, y: 2, z: 3});
    map.toObject(); // {x:1,y:2,z:3}
```
- Defined in map-constraint.ts:526

values

values(): V[]
The values, in order.

Returns V[]
Example
```
var map = cjs({x: 1, y: 2});
    map.values(); // [1,2]
```
- Defined in map-constraint.ts:170

Class MapConstraint<K, V>

Example

Type Parameters

Index

Constructors

Properties

Methods

Constructors

constructor

Type Parameters

Parameters

Returns MapConstraint<K, V>

Properties

Static ReadonlyBREAK

Methods

clear

Parameters

Returns this

Example

destroy

Parameters

Returns void

entries

Returns { key: K; value: V }[]

Example

forEach

Parameters

Returns this

Example

get

Parameters

Returns V | undefined

Example

getOrPut

Parameters

Returns V

Example

has

Parameters

Returns boolean

Example

indexOf

Parameters

Returns number

Example

isEmpty

Returns boolean

Example

item

Returns Record<string, V>

Example

Parameters

Returns V | undefined

Example

Parameters

Returns this

Example

itemConstraint

Parameters

Returns Constraint<V | undefined>

Example

keyForValue

Parameters

Returns K | undefined

Example

keys

Returns K[]

Example

move

Parameters

Returns this

Example

moveIndex

Parameters

Returns this

Example

put

Parameters

Returns this

Example

`Static` `Readonly`BREAK