jsonc-effect

Pure Effect JSONC (JSON with Comments) parser with no external parser dependencies. Scanner, parser, AST, and formatting are all implemented natively.

Features

• Effect-native -- typed errors, Schema integration, and composable pipelines
• Zero parser dependencies -- effect is the sole runtime dependency
• Schema integration -- parse JSONC strings directly into validated types
• Full toolchain -- scanner, parser, AST navigation, visitor stream, formatting, and modification
• Equality comparisons -- compare JSONC documents semantically, ignoring comments, formatting, and key ordering
• Safe by default -- returns unknown (not any) and Option (not undefined)

Installation

npm install jsonc-effect effect

Quick Start

import { parse } from "jsonc-effect"
import { Effect } from "effect"

const result = Effect.runSync(
  parse('{ "key": 42, /* comment */ }')
)
// => { key: 42 }

Semantically compare two JSONC documents:

import { equals } from "jsonc-effect"
import { Effect } from "effect"

// Semantically equal despite different formatting, comments, and key order
const same = Effect.runSync(
  equals(
    '{ "foo": 1, "bar": 2 }',
    '{ "bar": 2, /* comment */ "foo": 1 }'
  )
)
// => true

FAQ

Why does this module exist?

If you just need to parse JSONC into a JavaScript object, use jsonc-parser or Bun's native JSONC support. They are faster and have no dependencies.

This library is for Effect-based programs that need deeper introspection and editing of JSONC documents: typed parse errors you can catchTag, Schema pipelines that validate JSONC strings into domain types, AST navigation, document modification and SAX-style visitor streams that are composable in Effect pipelines.

Documentation

For API reference, advanced usage, and examples, see docs.

License

MIT