JS Built-in: Math, Date, JSON #99

Implement the Math, Date, and JSON built-in objects.

Scope#

Math#

• Not a constructor (static methods only)
• Constants: E, LN2, LN10, LOG2E, LOG10E, PI, SQRT1_2, SQRT2
• Methods: abs, ceil, floor, round, trunc
• max, min, pow, sqrt, cbrt, hypot
• sin, cos, tan, asin, acos, atan, atan2
• exp, log, log2, log10, expm1, log1p
• sign, clz32, fround
• random (basic PRNG — no crypto requirement)
• imul

Date#

• Date() constructor: no args (now), milliseconds, date string, year/month/day/...
• Date.now(), Date.parse(string), Date.UTC(...)
• Getters: getFullYear, getMonth, getDate, getDay, getHours, getMinutes, getSeconds, getMilliseconds, getTime, getTimezoneOffset
• UTC getters: getUTCFullYear, etc.
• Setters: setFullYear, setMonth, setDate, setHours, etc.
• toString, toISOString, toUTCString, toLocaleDateString, toJSON
• valueOf returns milliseconds since epoch
• Internal: convert between timestamp and calendar components

JSON#

• JSON.parse(text, reviver?) — parse JSON string to JS value
  • Support all JSON types: object, array, string, number, boolean, null
  • Optional reviver function
  • Throw SyntaxError on invalid JSON
• JSON.stringify(value, replacer?, space?)
  • Handle all primitive types
  • Handle objects and arrays recursively
  • toJSON() method support
  • Optional replacer (function or array)
  • Optional space for pretty printing
  • Circular reference detection (throw TypeError)

Acceptance Criteria#

• Math methods return correct values (test against known results)
• Date construction from various inputs
• Date getters/setters work correctly
• Date.now() returns reasonable timestamp
• JSON.parse handles all valid JSON
• JSON.parse throws on invalid JSON
• JSON.stringify handles nested objects/arrays
• JSON.stringify detects circular references
• Unit tests for each built-in

Phase 10 — JavaScript Engine (issue 10 of 15). Depends on: JS primitive built-ins (String/Number/Boolean/Symbol).