linkBoolean Operations

Boolean operations allow you to conduct boolean arithmetics on observables emitting boolean values.

linkEquality Checks

You can use eq() to check equality of multiple observables / boolean values:

1import { eq } from 'rxmetics';

2import { mod } from 'rxmetics/pipes';

3import { interval } from 'rxjs';

4

5

6eq(

7  interval(1000).pipe(mod(2)), 

8  interval(500).pipe(mod(2))

9).subscribe(console.log);

10

11// Result:

12// > true

13// > false

14// > true

15// > false

You can also use eq() pipe instead:

1import { mod, eq } from 'rxmetics/pipes';

2import { interval } from 'rxjs';

3

4

5interval(1000).pipe(

6  mod(2),

7  eq(interval(500).pipe(mod(2)))

8) 

9.subscribe(console.log);

You can also use neq() or neq() pipe for non-equality checks.

error IMPORTANT

eq() and neq() conduct strict equality check, i.e. they use === and !== operators respectively.

linknot()

Negates incoming boolean values:

1import { not, eq, neq } from 'rxmetics';

2import { interval } from 'rxjs';

3

4const i1 = interval(1000);

5const i2 = interval(1100);

6

7eq(

8  not(eq(i1, i2)),

9  neq(i1, i2)

10).subscribe(v => document.body.textContent = v);

You can use it as a pipe as well:

1import { not, eq, neq } from 'rxmetics';   // --> alternatively you can import `not` from 'rxmetics/pipes';

2import { interval } from 'rxjs';

3

4const i1 = interval(1000);

5const i2 = interval(1100);

6

7eq(

8  eq(i1, i2).pipe(not),

9  neq(i1, i2)

10).subscribe(v => document.body.textContent = v);

linkand()

Will AND two (or more) booleans or observables:

1import { and } from 'rxmetics';

2import { fromEvent } from 'rxjs';

3import { pluck, map } from 'rxjs/operators';

4

5

6and(

7  fromEvent(document, 'mousemove')

8    .pipe(pluck('clientX'), map(x => x > window.innerWidth / 2)),

9  fromEvent(document, 'mousemove')

10    .pipe(pluck('clientY'), map(x => x > window.innerHeight / 2))

11)

12.subscribe(v => {

13  if (v) document.body.classList.add('active');

14  else document.body.classList.remove('active');

15});

You can also use the and() pipe instead:

1import { and } from 'rxmetics/pipes';

2import { fromEvent } from 'rxjs';

3import { pluck, map } from 'rxjs/operators';

4

5fromEvent(document, 'mousemove')

6.pipe(

7  pluck('clientX'), map(x => x > window.innerWidth / 2),

8  and(fromEvent(document, 'mousemove')

9    .pipe(pluck('clientY'), map(x => x > window.innerHeight / 2))

10  )

11)

12.subscribe(v => {

13  if (v) document.body.classList.add('active');

14  else document.body.classList.remove('active');

15});

linkor()

Will AND two (or more) booleans or observables:

1import { or } from 'rxmetics';

2import { fromEvent } from 'rxjs';

3import { pluck, map } from 'rxjs/operators';

4

5

6or(

7  fromEvent(document, 'mousemove')

8    .pipe(pluck('clientX'), map(x => x > window.innerWidth / 2)),

9  fromEvent(document, 'mousemove')

10    .pipe(pluck('clientY'), map(x => x > window.innerHeight / 2))

11)

12.subscribe(v => {

13  if (v) document.body.classList.add('active');

14  else document.body.classList.remove('active');

15});

You can also use the and() pipe instead:

1import { or } from 'rxmetics/pipes';

2import { fromEvent } from 'rxjs';

3import { pluck, map } from 'rxjs/operators';

4

5fromEvent(document, 'mousemove')

6.pipe(

7  pluck('clientX'), map(x => x > window.innerWidth / 2),

8  or(fromEvent(document, 'mousemove')

9    .pipe(pluck('clientY'), map(x => x > window.innerHeight / 2))

10  )

11)

12.subscribe(v => {

13  if (v) document.body.classList.add('active');

14  else document.body.classList.remove('active');

15});

linktruthy()

Checks if emitted values are truthy. It basically applies the !! operator. Like not(), it can be used as a function or as a pipe:

1import { truthy, eq } from 'rxmetics';

2

3const a$ = ...

4

5truthy(a$)        // --> these two are the same

6a$.pipe(truthy)   // --> these two are the same