# Emitter

There are two `emitters` provided with the TypeScript compiler:

* `emitter.ts`: this is the emitter you are most likely to be interested in. Its the TS -> JavaScript emitter.
* `declarationEmitter.ts`: this is the emitter used to create a *declaration file* (a `.d.ts`) for a *TypeScript source file* (a `.ts` file).

We will look at `emitter.ts` in this section.

## Usage by `program`

Program provides an `emit` function. This function primarily delegates to `emitFiles` function in `emitter.ts`. Here is the call stack:

```
Program.emit ->
    `emitWorker` (local in program.ts createProgram) ->
        `emitFiles` (function in emitter.ts)
```

One thing that the `emitWorker` provides to the emitter (via an argument to `emitFiles`) is an `EmitResolver`. `EmitResolver` is provided by the program's TypeChecker, basically it is a subset of *local* functions from `createChecker`.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://radlohead.gitbook.io/typescript-deep-dive/overview/emitter.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.