diff options
| -rw-r--r-- | parse.go | 6 | ||||
| -rw-r--r-- | usage.go | 44 | ||||
| -rw-r--r-- | usage_test.go | 1 |
3 files changed, 31 insertions, 20 deletions
@@ -19,6 +19,7 @@ type spec struct { positional bool help string wasPresent bool + isBool bool } // ErrHelp indicates that -h or --help were provided @@ -100,6 +101,11 @@ func NewParser(dests ...interface{}) (*Parser, error) { return nil, fmt.Errorf("%s.%s: %s fields are not supported", t.Name(), field.Name, scalarType.Kind()) } + // Specify that it is a bool for usage + if scalarType.Kind() == reflect.Bool { + spec.isBool = true + } + // Look at the tag if tag != "" { for _, key := range strings.Split(tag, ",") { @@ -5,7 +5,6 @@ import ( "io" "os" "path/filepath" - "reflect" "strings" ) @@ -78,30 +77,35 @@ func (p *Parser) WriteHelp(w io.Writer) { } // write the list of options - if len(options) > 0 { - fmt.Fprint(w, "\noptions:\n") - const colWidth = 25 - for _, spec := range options { - left := " " + synopsis(spec, "--"+spec.long) - if spec.short != "" { - left += ", " + synopsis(spec, "-"+spec.short) - } - fmt.Fprint(w, left) - if spec.help != "" { - if len(left)+2 < colWidth { - fmt.Fprint(w, strings.Repeat(" ", colWidth-len(left))) - } else { - fmt.Fprint(w, "\n"+strings.Repeat(" ", colWidth)) - } - fmt.Fprint(w, spec.help) - } - fmt.Fprint(w, "\n") + fmt.Fprint(w, "\noptions:\n") + for _, spec := range options { + printOption(w, spec) + } + + // write the list of built in options + printOption(w, &spec{isBool: true, long: "help", short: "h", help: "display this help and exit"}) +} + +func printOption(w io.Writer, spec *spec) { + const colWidth = 25 + left := " " + synopsis(spec, "--"+spec.long) + if spec.short != "" { + left += ", " + synopsis(spec, "-"+spec.short) + } + fmt.Fprint(w, left) + if spec.help != "" { + if len(left)+2 < colWidth { + fmt.Fprint(w, strings.Repeat(" ", colWidth-len(left))) + } else { + fmt.Fprint(w, "\n"+strings.Repeat(" ", colWidth)) } + fmt.Fprint(w, spec.help) } + fmt.Fprint(w, "\n") } func synopsis(spec *spec, form string) string { - if spec.dest.Kind() == reflect.Bool { + if spec.isBool { return form } return form + " " + strings.ToUpper(spec.long) diff --git a/usage_test.go b/usage_test.go index 83da1c1..5a9199c 100644 --- a/usage_test.go +++ b/usage_test.go @@ -23,6 +23,7 @@ options: --dataset DATASET dataset to use --optimize OPTIMIZE, -O OPTIMIZE optimization level + --help, -h display this help and exit ` var args struct { Input string `arg:"positional"` |