type

double

double

A double is an IEEE-754 double-precision number: about sixteen significant digits. Use it where a float loses precision — large world coordinates, accumulated time, geodesy — and convert to float at the boundary to the GPU.

It behaves like float: decimal literals take its type from context, int and long promote to it, and a float mixed with a double widens to double. Narrowing back is explicit: float(d).

Example

program Precise {
  entry {
    let total: double = 0.1
    print(total + 0.2)                 # 0.30000000000000004
    let small: float = float(total)
    print(small)                       # 0.1
  }
}

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