Basic value validation methods

[willfaught]

It'd be useful to have basic validation methods like:

Flag(...).Positive().Int()
Flag(...).Range(1, 10).Int()
Flag(...).MatchRegexp(`\w\d\w`).String()

[alecthomas]

On the one hand I feel like this is a slippery slope, given how many different data types and potential validators there are. On the other hand, it does make those use cases it covers much more convenient.

[willfaught]

Another thing to consider is whether they should be reflected in the help, and if so, how.

[benjaminch]

Thinking about it, maybe would be good to add a case where we allow the flag to take only some values.

Flag(...).OneOf('jpg', 'png', 'gif').String()

Would be nice to add those in help as well with a default text for every validation check which should be overridable as well if needed.

[alecthomas]

Enum() does this already, but only for strings. On Sun, 20 Aug 2017 at 1:58 am, Benjamin [email protected] wrote:

Thinking about it, maybe would be good to add a case where we allow the flag to take only some values. Flag(...).OneOf('jpg', 'png', 'gif').String()

Would be nice to add those in help as well with a default text for every validation check which should be overridable as well if needed.

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[willfaught]

Closing due to no activity.