bobziuchkovski / writ Goto Github PK

E.g. if -a and -b are both specified then the last one specified will be used.

A workaround might be adding --mode option and specify --mode=a or --mode=b.

I'd propose to extend/change the OptionDecoder interface, where both option name and value are passed to the Decode function.

Is it possible to get the filenames for io.Reader and io.Writer options? I like the automatic handling of them, but still prefer to sometimes get to the filenames (for error messages and the like)

Setting a placeholder:"<some-thing>" as a struct tag for types other thanstring` causes the option parsing to silently fail and omit that option:

type Config struct {
    # Included
    Start     int64  `option:"start-time" description:"The timestamp (in Unix seconds) to request logs from."`
    # Omitted (i.e. not parsed, not included in help text)
    End       int64  `option:"end-time" placeholder="<unix-timestamp>" description:"The timestamp (in Unix seconds) to request logs to."`
    # Included  Count     int    `option:"c, count" default:"1" description:"The number (count) of logs to retrieve."`
}

Is this intended? Can be useful to describe formatting.

$ cat test.go

package main

import (
        "os"

        "github.com/bobziuchkovski/writ"
)

type Foo struct {
        Bar Bar `command:"bar"`
}

type Bar struct {
        HelpFlag bool `flag:"h, help"`
}

func main() {
        foo := &Foo{}
        cmd := writ.New("foo", foo)
        path, _, err := cmd.Decode(os.Args[1:])
        if err != nil {
                path.Last().ExitHelp(err)
        }
}

$ go run test.go bar --help --help

Usage: foo bar [OPTION]... [ARG]...

Error: option "bar" specified too many times
exit status 1

I believe the error message should be option "help" specified too many times

Has an Option.Default field been considered? I prefer to write options without struct tags (since struct tags aren't checked by the compiler, leading to my issue yesterday), but right now you need to write the following:

    {
        Names:       []string{"count"},
        Description: "The (maximum) number of logs to request.",
        Placeholder: "<num>",
        Decoder:     writ.NewDefaulter(writ.NewOptionDecoder(config.Count), "1"),
    },

This isn't bad, but it:

• Limits you to strings - if the field is an int64 or other time (say, for Unix timestamps) then you can't set a default.
• A Default field would be more explicit and would better map against the existing struct tag names.

This allows you to have a common set of options/flags across sub-commands - e.g.

type Common struct {
    FileName string
    Headers string
    ...
}

type Fetch struct {
    Common
    From string
}

type Restore struct {
    Common
    To []string
}

The structs here are simple, but should illustrate the use-case. The embedded struct does not seem to be parsed.