#@mizchi/jsonschema

$ moon add mizchi/jsonschema

#Features

• JSON Schema validation with $ref support
• Schema builder (valibot-style API)
• MoonBit code generation from JSON Schema

#Package Structure

mizchi/jsonschema/
  types/     # Schema type definitions
  parser/    # JSON Schema parser (opt-in)
  validate/  # Validation implementation
  codegen/   # Code generation
  exports/   # Main exports for JS

#Usage

#Schema Builder (Recommended)

let schema = object_schema(
  properties=Some({
    "name": string_schema(min_length=Some(1)),
    "age": integer_schema(minimum=Some(0)),
  }),
  required=Some(["name"]),
)

let result = validate_schema(schema, { "name": "John", "age": 30 })

#JSON Schema Parsing

let raw : Json = {
  "type": "object",
  "properties": {
    "name": { "type": "string" },
    "age": { "type": "integer" }
  },
  "required": ["name"]
}

let validator = build_validator(raw)
let result = validator.validate({ "name": "John", "age": 30 })

#Supported Features

• type: any, null, boolean, string, number, integer, array, object
• String: minLength, maxLength, enum
• Number/Integer: minimum, maximum, exclusiveMinimum, exclusiveMaximum, multipleOf
• Array: items, minItems, maxItems, prefixItems
• Object: properties, required, additionalProperties
• Combinators: anyOf, allOf, oneOf
• $ref with JSON Pointer (#/definitions/Foo)
• const, enum
• Multiple types: { "type": ["string", "null"] }

#Performance

#Recommended Target

#Benchmark Results (wasm-gc)

#Performance Tips

1. Use Schema Builder - Pre-built schemas skip parsing overhead (~10x faster)

// Fast: schema is pre-built
let schema = object_schema(properties=Some({ "name": string_schema() }))
let result = validate_schema(schema, input)

// Slower: requires parsing JSON Schema
let validator = build_validator({ "type": "object", ... })

2. Reuse Validators - Build once, validate many times

let validator = build_validator(schema_json)  // Build once
for input in inputs {
  validator.validate(input)  // Reuse
}

3. Use wasm-gc target - 2-7x faster than other targets

#Known Limitations

• patternProperties: Not implemented
• Grapheme cluster counting: minLength/maxLength count UTF-16 code units, not Unicode grapheme clusters

#LICENSE