json5
JSON5 parser and stringifier for MoonBit
json
json5
Author
Version
0.0.3
License
Apache-2.0
Repository
Last updated
3 months ago
Downloads
60
#tiye/json5
This document was generated with AI assistance and then reviewed/edited for this project. Contributions are welcome via PRs, and AI-assisted review may be used during the review process.
A lightweight JSON5 parser/serializer for MoonBit.
This package lets you parse JSON5 input (comments, trailing commas, single-quoted strings, unquoted keys, hex numbers, Infinity, NaN) and work with either:
- Json5Value (package-native value tree), or
- core Json (via helper APIs and traits).
#Features
- Parse JSON5 object/array/value syntax
- Support line comments // ... and block comments /* ... */
- Support trailing commas in objects and arrays
- Support unquoted object keys (identifier style)
- Support single-quoted strings
- Support number forms: decimal, exponent, hex (0x10), Infinity, NaN
- Convert between Json5Value and core Json using ToJson / FromJson
#Installation
Add this package to your MoonBit module dependencies (according to your workspace setup), then import and use:
///|
let value = @json5.parse("{foo: 'bar'}")#Quick Start
#Parse to Json5Value
///|
test "readme parse json5 value" {
let value = @json5.parse("{foo: 'bar', nums: [1, 2,],}")
guard value is @json5.Object(obj)
assert_true(obj.get("foo") is Some(_))
}#Stringify from Json5Value
///|
test "readme stringify json5 value" {
let value = @json5.parse("{ok: true}")
let text = @json5.stringify(value)
// valid identifiers are written unquoted in JSON5
assert_true(text.contains("ok:true"))
}#Parse directly to core Json
///|
test "readme parse json5 to json" {
let json = @json5.parse_json("{foo: [1, true, 'x']}")
@json.json_inspect(json, content={ "foo": [1, true, "x"] })
}#Stringify from core Json
///|
test "readme stringify json" {
let text = @json5.stringify_json({ "name": "moonbit", "v": 1 })
// valid identifiers are written unquoted in JSON5
assert_true(text.contains("name:\"moonbit\""))
}#Public API
- parse(input : String) -> Json5Value raise Error
- parse_json(input : String) -> Json raise Error
- stringify(val : Json5Value) -> String
- stringify_json(json : Json) -> String raise @json.JsonDecodeError
Types:
- pub enum Json5Value { Null | True | False | Number(Double) | String(String) | Array(Array[Json5Value]) | Object(Map[String, Json5Value]) }
Traits:
- impl ToJson for Json5Value
- impl @json.FromJson for Json5Value
#Error Handling
- parse / parse_json raise Error for malformed JSON5 text.
- stringify_json raises @json.JsonDecodeError if conversion from core Json to Json5Value fails.
Use try/catch when you need resilient decoding.
#Current Limitations
- Unicode escape in strings (\uXXXX) is not implemented yet.
- Serializer currently outputs compact text only (no pretty formatting mode).
#Tests
Run:
moon testJson5Value
pub enum Json5Value {
Null
True
False
Number(Double)
String(String)
Array(Array[Json5Value])
Object(Map[String, Json5Value])
} derive(Eq, Debug)Represents a JSON5 value tree.
This enum is the primary data model for parsed JSON5 content in this
package. It mirrors regular JSON shapes while preserving JSON5-friendly
numeric forms during parsing (for example NaN and Infinity).
Variants:
- Null
- True
- False
- Number(Double)
- String(String)
- Array(Array[Json5Value])
- Object(Map[String, Json5Value])
Example:
test {
let value = @json5.parse("{foo: [1, true, 'x']}")
guard value is Object(obj)
assert_true(obj.get("foo") is Some(Array(_)))
}impl Show for Json5ValueRenders Json5Value as compact JSON5 text for display.
impl ToJson for Json5ValueConverts Json5Value to core Json.
This is useful when you want to parse with JSON5 syntax and then operate
with MoonBit's standard @json ecosystem.
Notes:
- NaN and infinities are delegated to Double::to_json behavior.
- Object key order follows the underlying map iteration order.
impl FromJson for Json5ValueConverts core Json to Json5Value.
This implementation is recursive and propagates JSON path information to
nested conversions, making decode errors easier to locate.
Typical usage:
test {
let json : Json = { "name": "moonbit", "ok": true }
let value : @json5.Json5Value = @json.from_json(json)
guard value is Object(obj)
assert_true(obj.get("name") is Some(_))
}parse
Parses a JSON5 text into Json5Value.
This is the primary entry point for JSON5 parsing in this package.
Raises Error for malformed input.
Example:
test {
let value = @json5.parse("{foo: 'bar', nums: [1, 2,],}")
guard value is Object(obj)
assert_true(obj.get("foo") is Some(_))
}parse_json
Parses JSON5 text directly into core Json.
This helper is convenient when your downstream code already uses @json
APIs and you do not need to manually inspect Json5Value.
Equivalent to:
parse(input).to_json()
stringify
Serializes Json5Value to compact text.
Object keys that are valid JSON5 identifiers are written unquoted;
all other keys are quoted.
Number behavior:
- finite numbers: normal decimal formatting
- NaN: "NaN"
- positive infinity: "Infinity"
- negative infinity: "-Infinity"
Example:
test {
let value = @json5.parse("{foo: 'bar'}")
let text = @json5.stringify(value)
assert_true(text.contains("foo:\"bar\""))
}stringify_json
Serializes core Json to compact JSON5 text.
Object keys that are valid JSON5 identifiers are written unquoted.
stringify_json_pretty
Serializes core Json to a pretty-printed JSON5 string.
Convenience wrapper around stringify_pretty that converts Json first.
The indent_size labeled argument defaults to 2.
stringify_pretty
Serializes Json5Value to a pretty-printed JSON5 string.
Object keys that are valid JSON5 identifiers are written unquoted.
The indent_size labeled argument controls indentation spaces per level
and defaults to 2.
Example:
test {
let value = @json5.parse("{foo: [1, true]}")
let text = @json5.stringify_pretty(value)
assert_true(text.contains("foo: [\n"))
}Source Files
Install
Download zipJSON5 parser and stringifier for MoonBit
jsonjson5
0.0.3
Apache-2.0
Updated 3 months ago
60 downloads