vikunja-api/vendor/github.com/urfave/cli/parse.go
2019-10-16 20:52:29 +00:00

80 lines
1.9 KiB
Go

package cli
import (
"flag"
"strings"
)
type iterativeParser interface {
newFlagSet() (*flag.FlagSet, error)
useShortOptionHandling() bool
}
// To enable short-option handling (e.g., "-it" vs "-i -t") we have to
// iteratively catch parsing errors. This way we achieve LR parsing without
// transforming any arguments. Otherwise, there is no way we can discriminate
// combined short options from common arguments that should be left untouched.
func parseIter(ip iterativeParser, args []string) (*flag.FlagSet, error) {
for {
set, err := ip.newFlagSet()
if err != nil {
return nil, err
}
err = set.Parse(args)
if !ip.useShortOptionHandling() || err == nil {
return set, err
}
errStr := err.Error()
trimmed := strings.TrimPrefix(errStr, "flag provided but not defined: ")
if errStr == trimmed {
return nil, err
}
// regenerate the initial args with the split short opts
newArgs := []string{}
for i, arg := range args {
if arg != trimmed {
newArgs = append(newArgs, arg)
continue
}
shortOpts := splitShortOptions(set, trimmed)
if len(shortOpts) == 1 {
return nil, err
}
// add each short option and all remaining arguments
newArgs = append(newArgs, shortOpts...)
newArgs = append(newArgs, args[i+1:]...)
args = newArgs
}
}
}
func splitShortOptions(set *flag.FlagSet, arg string) []string {
shortFlagsExist := func(s string) bool {
for _, c := range s[1:] {
if f := set.Lookup(string(c)); f == nil {
return false
}
}
return true
}
if !isSplittable(arg) || !shortFlagsExist(arg) {
return []string{arg}
}
separated := make([]string, 0, len(arg)-1)
for _, flagChar := range arg[1:] {
separated = append(separated, "-"+string(flagChar))
}
return separated
}
func isSplittable(flagArg string) bool {
return strings.HasPrefix(flagArg, "-") && !strings.HasPrefix(flagArg, "--") && len(flagArg) > 2
}