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filter

Instance method on Array.prototype.

Returns the elements of an array that meet the condition specified in a callback function.

filter(input: { array: <receiver>; predicate?: (value: T; index: number; array: T[]) => boolean; thisArg?: any; prompt?: string }): Promise<S[]>
filter(input: { array: <receiver>; predicate?: (value: T; index: number; array: T[]) => unknown; thisArg?: any; prompt?: string }): Promise<T[]>

The prompt field is optional. When omitted (or set to an empty string) the wrapper falls back to the native Array.prototype.filter and returns a resolved Promise without contacting the LLM. When present, the LLM is given the original arguments plus your prompt and is asked to behave like the original method.

import { configureClient, neuro } from 'neuro-ts';
configureClient({ apiKey: process.env.OPENAI_API_KEY });
// Filter by the current rule, while remembering that the rule is the one we changed last sprint.
await neuro.array.filter({ array: tickets, predicate: (t) => t.severity > 1, prompt: 'keep only the items the predicate calls true today, but warn me about the ones the predicate would have rejected last release' });

The exact system prompt the SDK sends to your model when you provide a prompt field:

Generated promptArray.prototype.filter
You are simulating the JavaScript built-in `Array.prototype.filter`.
## Original signature(s)
  Overload 1: (predicate?: (value: T, index: number, array: T[]) => boolean, thisArg?: any) => S[]
  Overload 2: (predicate?: (value: T, index: number, array: T[]) => unknown, thisArg?: any) => T[]
## JSDoc
Returns the elements of an array that meet the condition specified in a callback function.

## How to respond
- Behave EXACTLY as the original `filter` would, but use the user's intent to choose any callback / comparator / transform logic that the original would normally accept as an argument.
- Strictly preserve the original return type and shape.
- Output ONLY the JSON-encoded return value of the function call.
- Do NOT include explanations, prose, comments, or markdown fences.
- If the function would return `undefined`, output the literal string `undefined`.
- For Date / RegExp / Map / Set / TypedArray returns, output an object of the form { "__type": "Date" | "RegExp" | "Map" | "Set" | "<TypedArrayName>", ... } so the SDK can rehydrate it.