v0.4.0

Added

• Comment Support: CTON now supports single-line comments using # syntax. Comments are ignored during parsing, allowing for annotated data files.

  • Decoder skips comments (from # to end of line) during parsing
  • Encoder can emit comments via new comments: option: Cton.dump(data, comments: { "key" => "description" })

• Validation API: New methods to validate CTON syntax without full parsing:

  • Cton.valid?(string) returns true or false
  • Cton.validate(string) returns a ValidationResult object with detailed error information
  • ValidationResult includes valid?, errors, and to_s methods
  • ValidationError includes message, line, column, and source_excerpt

• Token Statistics API: Analyze and compare CTON vs JSON token efficiency:

  • Cton.stats(data) returns a Stats object with comprehensive metrics
  • Cton.stats_hash(data) returns stats as a Hash
  • Stats includes json_chars, cton_chars, savings_percent, estimated_json_tokens, estimated_cton_tokens
  • Stats.compare(data) compares multiple format variants (CTON, CTON inline, CTON pretty, JSON, JSON pretty)

• Custom Type Registry: Register custom serializers for domain objects:

  • Cton.register_type(klass, as: :object) { |value| ... } registers a type handler
  • Cton.unregister_type(klass) removes a handler
  • Cton.clear_type_registry! clears all handlers
  • Supports :object, :array, and :scalar modes

• Enhanced CLI: New command-line options:

  • --stats / -s: Show token savings statistics comparing JSON vs CTON
  • --validate: Validate CTON syntax without conversion
  • --minify / -m: Output CTON without separators (fully inline)
  • Improved error messages with line/column information and colored output

• Enhanced Error Reporting: ParseError now includes structured location information:

  • line and column attributes for precise error location
  • source_excerpt showing context around the error
  • suggestions array for helpful hints
  • to_h method for programmatic error handling