diff --git a/docs_app/content/guide/operators.md b/docs_app/content/guide/operators.md index 086e6a97b1..0bf43fddcf 100644 --- a/docs_app/content/guide/operators.md +++ b/docs_app/content/guide/operators.md @@ -6,10 +6,14 @@ RxJS is mostly useful for its _operators_, even though the Observable is the fou Operators are **functions**. There are two kinds of operators: -**Pipeable Operators** are the kind that can be piped to Observables using the syntax `observableInstance.pipe(operator())`. These include, [`filter(...)`](/api/operators/filter), and [`mergeMap(...)`](/api/operators/mergeMap). When called, they do not _change_ the existing Observable instance. Instead, they return a _new_ Observable, whose subscription logic is based on the first Observable. +**Pipeable Operators** are the kind that can be piped to Observables using the syntax `observableInstance.pipe(operator)` or, more commonly, `observableInstance.pipe(operatorFactory())`. Operator factory functions include, [`filter(...)`](/api/operators/filter), and [`mergeMap(...)`](/api/operators/mergeMap). + +When Pipeable Operators are called, they do not _change_ the existing Observable instance. Instead, they return a _new_ Observable, whose subscription logic is based on the first Observable. A Pipeable Operator is a function that takes an Observable as its input and returns another Observable. It is a pure operation: the previous Observable stays unmodified. +A Pipeable Operator Factory is a function that can take parameters to set the context and return a Pipeable Operator. The factory’s arguments belong to the operator’s lexical scope. + A Pipeable Operator is essentially a pure function which takes one Observable as input and generates another Observable as output. Subscribing to the output Observable will also subscribe to the input Observable. **Creation Operators** are the other kind of operator, which can be called as standalone functions to create a new Observable. For example: `of(1, 2, 3)` creates an observable that will emit 1, 2, and 3, one right after another. Creation operators will be discussed in more detail in a later section.