functionGemmaDouble function

String functionGemmaDouble(double value)

Python's str(float). The template is Jinja, so every number in the prompt was formatted by Python. Both languages print the shortest round-trip digits, but they switch to exponent notation at different magnitudes: Python below 1e-4 and from 1e16, Dart below 1e-6 and from 1e21.

Implementation

String functionGemmaDouble(double value) {
  if (value.isNaN) return 'nan';
  if (value.isInfinite) return value.isNegative ? '-inf' : 'inf';

  final magnitude = value.abs();
  if (magnitude == 0 || (magnitude >= 1e-4 && magnitude < 1e16)) {
    return value.toString();
  }

  // Dart writes `1e-5`, Python pads the exponent to two digits: `1e-05`.
  final exponential = value.toStringAsExponential();
  final parts = RegExp(r'^(.*)e([+-])(\d+)$').firstMatch(exponential);
  if (parts == null) return exponential;
  return '${parts.group(1)}e${parts.group(2)}${parts.group(3)!.padLeft(2, '0')}';
}