On 06/05/2011 23:51, Cameron Simpson wrote:
On 06May2011 15:40, Ethan Furman<ethan@stoneleaf.us> wrote: | Bruce Leban wrote: |>Is _ just ignored in numbers or are there more complex rules? |> |> * 1_2345_6789 (can I use groups of other sizes instead?) |> * 1_2_3_4_5 (ditto) |> * 1_234_6789 (do all the groups need to be the same size?) |> * 1_ (must the _ only be in between 2 digits?) |> * 1__234 (what about multiple _s?) |> * 9.876_543_210 (can it be used to the right of the decimal point?) |> * 0xFEFF_0042 (can it be used in hex, octal or binary numbers?) |> * int('123_456') (do other functions accept this syntax too?) | | I would say it's ignored. Have the rule be something like | number_string.replace('_',''). | | The only wrinkle is that currently '_1' is usable name, and that | should probably be disallowed if the above change took place. | | I'm +1 on the idea.
Personally I'm be for ignoring the _ also, save that I would forbid it at the start or end, so no _1 or 1_.
And I would permit it in hex code etc.
I'm +0.5, myself.
As far as I remember, Ada also permits it, but has the rule that it can occur only between digits. If we follow that, then: 1_2345_6789 => Yes 1_2_3_4_5 => Yes 1_234_6789 => Yes 1_ => No _1 => No 1__234 => No 9.876_543_210 => Yes 9._876_543_210 => No 9_.876_543_210 => No 0xFEFF_0042 => Yes int('123_456') => Yes