> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metz.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# The Standard Library

It is exposed through the global variable `std` and has everything needed to interact with the runtime and other helpers.

# `resolve`

Takes a class reference and gets its instance from the DI container.

<Tabs>
  <Tab title="Params">
    <ParamField path="classReference" type="Class" required>
      A reference to a class participating in [Dependency Injection](/dependencies-and-scope/dependencies#dependency-injection)
    </ParamField>
  </Tab>

  <Tab title="Result">
    <ResponseField name="classInstance" type="Object">
      Instance of given class reference.
    </ResponseField>
  </Tab>
</Tabs>

**Example**

To retreive an instance of a class called `LoadBalancer`, you'd write:

```typescript theme={null}
  const loadBalancer = std.resolve(LoadBalancer);
```

<Warning>If the param is a class that is not decorated with `@Injectable` then this will throw an error!</Warning>

<br />

# `flow`

Helper to create [flows](/flows-101).

<Tabs>
  <Tab title="Params">
    <ParamField path="name" type="string" required>
      Name of the flow
    </ParamField>

    <ParamField path="classInstance" type="Object" required>
      An instance of a class
    </ParamField>

    <ParamField path="schedule" type="Object">
      ```typescript theme={null}
      { after: number } | { every: number }
      ```

      This param enables you to create [Scheduled Flows](/flows-102#scheduled-flows)
    </ParamField>
  </Tab>

  <Tab title="Result">
    <ResponseField name="flowGenerator" type="FlowGenerator">
      A `FlowGenerator` enables you to run flows. See more [here](/flows-102).
    </ResponseField>
  </Tab>
</Tabs>

<br />

# `log`

Equivalent of [console.log](https://developer.mozilla.org/en-US/docs/Web/API/console/log_static). Halts the execution.

<Tabs>
  <Tab title="Params">
    <ParamField path="messages" type="...any[]">
      You can pass any number of messages of any type.
    </ParamField>
  </Tab>
</Tabs>

**Example**

```typescript theme={null}
  std.log("This is pretty", 1337);
```

<br />

# `lambda`

<Warning>This is experimental</Warning>
Wrapper to skip higher order functions getting transformed by compiler. See [this](/hof).

<Tabs>
  <Tab title="Params">
    <ParamField path="fn" type="Function" required>
      The function you want to pass around.
    </ParamField>
  </Tab>

  <Tab title="Result">
    <ResponseField name="fn" type="Function">
      Returns the same function, unchanged.
    </ResponseField>
  </Tab>
</Tabs>

<br />

# `currentTick`

Equivalent to `System.currentTimeMillis()` or `Date.now()` but follows [temporal rules](/runtime#time-stands-still) of runtime.

<Tabs>
  <Tab title="Result">
    <ResponseField name="tick" type="number">
      Returns the current tick/time.
    </ResponseField>
  </Tab>
</Tabs>

<br />

# `sleep`

Halts the flow for given number of ticks.

<Tabs>
  <Tab title="Params">
    <ParamField path="ticks" type="number" required>
      Number of ticks the flow should halt for.
    </ParamField>
  </Tab>
</Tabs>

<br />

# `awaitAll`

Suspends the current flow till all the given flows complete. See [here](/awaiting-flows#std-awaitall).

<Tabs>
  <Tab title="Params">
    <ParamField path="flowExecutors" type="FlowExecutor[]" required>
      The flows you want to await on.
    </ParamField>
  </Tab>

  <Tab title="Result">
    <ResponseField name="result" type="T[]">
      An array of results of the given flows.
    </ResponseField>
  </Tab>
</Tabs>

<br />

# `awaitRace`

Suspends the current flow till one of the given flows complete. See [here](/awaiting-flows#std-awaitrace).

<Tabs>
  <Tab title="Params">
    <ParamField path="flowExecutors" type="FlowExecutor[]" required>
      The flows you want to race.
    </ParamField>
  </Tab>

  <Tab title="Result">
    <ResponseField name="result" type="T">
      The result of the flow that completed first.
    </ResponseField>
  </Tab>
</Tabs>

<br />

# `createChannelEmitter`

Creates a channel emitter which lets you push events for given topic. See [this](/events).

<Tabs>
  <Tab title="Params">
    <ParamField path="topic" type="string" required>
      A dedicated channel will be created for the topic.
    </ParamField>
  </Tab>

  <Tab title="Result">
    <ResponseField name="emitter" type="ChannelEmitter">
      Simply call `emit` on it to start pushing events.
    </ResponseField>
  </Tab>
</Tabs>

<br />

# `registerChannelListener`

Lets you susbscribe to topics. See [this](/events).

<Tabs>
  <Tab title="Params">
    <ParamField path="topic" type="string" required>
      The topic to listen.
    </ParamField>

    <ParamField path="listener" type="(data: T) => FlowExecutor" required>
      The function to invoke whenever there's an event pushed for given topic.
    </ParamField>
  </Tab>
</Tabs>