effect-io-ai

Package: effect
Module: Formatter

Formatter.format

Converts any JavaScript value into a human-readable string.

When to use

Use when you need to format arbitrary JavaScript values for debugging, logging, or error messages.

Details

• Output is not valid JSON; use formatJson when you need parseable JSON.
• Handles BigInt, Symbol, Set, Map, Date, RegExp, and class instances that JSON.stringify cannot represent.
• Circular references are shown as "[Circular]" instead of throwing.
• Primitives: stringified naturally (null, undefined, 123, true). Strings are JSON-quoted.
• Objects with a custom toString (not Object.prototype.toString): toString() is called unless ignoreToString is true.
• Errors with a cause: formatted as "<message> (cause: <cause>)".
• Iterables (Set, Map, etc.): formatted as ClassName([...elements]).
• Class instances: wrapped as ClassName({...}).
• Redactable values are automatically redacted.
• Arrays/objects with 0–1 entries are inline; larger ones are pretty-printed when space is set.
• space — indentation unit (number of spaces, or a string like "\t"). Defaults to 0 (compact).
• ignoreToString — skip calling toString(). Defaults to false.

Example (Formatting compact output)

import { Formatter } from "effect"

console.log(Formatter.format({ a: 1, b: [2, 3] }))
// {"a":1,"b":[2,3]}

Example (Pretty-printed output)

import { Formatter } from "effect"

console.log(Formatter.format({ a: 1, b: [2, 3] }, { space: 2 }))
// {
//   "a": 1,
//   "b": [
//     2,
//     3
//   ]
// }

Example (Handling circular references)

import { Formatter } from "effect"

const obj: any = { name: "loop" }
obj.self = obj
console.log(Formatter.format(obj))
// {"name":"loop","self":[Circular]}

See

• formatJson
• Formatter

Signature

declare const format: (input: unknown, options?: { readonly space?: number | string | undefined; readonly ignoreToString?: boolean | undefined; }) => string

Source

Since v2.0.0