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cppnix_format_float

sui_compat::versions

Function cppnix_format_float 

Source 
pub fn cppnix_format_float(f: f64) -> String
Expand description

Format a f64 the way CppNix does — printf("%g", f) semantics with 6 significant digits, trailing-zero strip, no decimal point for whole numbers.

Examples matching nix eval byte-for-byte (verified on cppnix 2.30 / cid 2026-05-23):

  • 1.0 / 3.0 → "0.333333"
  • 10.0 / 3.0 → "3.33333" (6 sig digits, not 6 decimal places)
  • 3.14159 → "3.14159"
  • 12.345 → "12.345"
  • 1.5 → "1.5"
  • 3.0 → "3"
  • 5.0 - 2.0 → "3"
  • 0.0 → "0"
  • 0.0001 → "0.0001"
  • NaN → "NaN"
  • inf → "inf"

Used by every engine’s float Display impl (Value::Float, VMValue::Float, StringKeyedValue::Float) so probe JSON round-trips byte-identically against cppnix.