diff options
| -rw-r--r-- | parse.go | 27 | ||||
| -rw-r--r-- | usage.go | 2 |
2 files changed, 20 insertions, 9 deletions
@@ -346,7 +346,7 @@ func (p *Parser) process(specs []*spec, args []string) error { err, ) } - if err = setSlice(p.settable(spec), values, !spec.separate); err != nil { + if err = setSlice(p.writable(spec), values, !spec.separate); err != nil { return fmt.Errorf( "error processing environment variable %s with multiple values: %v", spec.env, @@ -354,7 +354,7 @@ func (p *Parser) process(specs []*spec, args []string) error { ) } } else { - if err := scalar.ParseValue(p.settable(spec), value); err != nil { + if err := scalar.ParseValue(p.writable(spec), value); err != nil { return fmt.Errorf("error processing environment variable %s: %v", spec.env, err) } } @@ -407,7 +407,7 @@ func (p *Parser) process(specs []*spec, args []string) error { } else { values = append(values, value) } - err := setSlice(p.settable(spec), values, !spec.separate) + err := setSlice(p.writable(spec), values, !spec.separate) if err != nil { return fmt.Errorf("error processing %s: %v", arg, err) } @@ -432,7 +432,7 @@ func (p *Parser) process(specs []*spec, args []string) error { i++ } - err := scalar.ParseValue(p.settable(spec), value) + err := scalar.ParseValue(p.writable(spec), value) if err != nil { return fmt.Errorf("error processing %s: %v", arg, err) } @@ -448,13 +448,13 @@ func (p *Parser) process(specs []*spec, args []string) error { } wasPresent[spec] = true if spec.multiple { - err := setSlice(p.settable(spec), positionals, true) + err := setSlice(p.writable(spec), positionals, true) if err != nil { return fmt.Errorf("error processing %s: %v", spec.long, err) } positionals = nil } else { - err := scalar.ParseValue(p.settable(spec), positionals[0]) + err := scalar.ParseValue(p.writable(spec), positionals[0]) if err != nil { return fmt.Errorf("error processing %s: %v", spec.long, err) } @@ -497,7 +497,9 @@ func isFlag(s string) bool { return strings.HasPrefix(s, "-") && strings.TrimLeft(s, "-") != "" } -func (p *Parser) get(spec *spec) reflect.Value { +// readable returns a reflect.Value corresponding to the current value for the +// given +func (p *Parser) readable(spec *spec) reflect.Value { v := p.roots[spec.root] for _, field := range spec.path { if v.Kind() == reflect.Ptr { @@ -509,6 +511,9 @@ func (p *Parser) get(spec *spec) reflect.Value { v = v.FieldByName(field) if !v.IsValid() { + // it is appropriate to panic here because this can only happen due to + // an internal bug in this library (since we construct spec.path ourselves + // by reflecting on the same struct) panic(fmt.Errorf("error resolving path %v: %v has no field named %v", spec.path, v.Type(), field)) } @@ -516,7 +521,10 @@ func (p *Parser) get(spec *spec) reflect.Value { return v } -func (p *Parser) settable(spec *spec) reflect.Value { +// writable traverses the destination struct to find the destination to +// which the value of the given spec should be written. It fills in null +// structs with pointers to the zero value for that struct. +func (p *Parser) writable(spec *spec) reflect.Value { v := p.roots[spec.root] for _, field := range spec.path { if v.Kind() == reflect.Ptr { @@ -528,6 +536,9 @@ func (p *Parser) settable(spec *spec) reflect.Value { v = v.FieldByName(field) if !v.IsValid() { + // it is appropriate to panic here because this can only happen due to + // an internal bug in this library (since we construct spec.path ourselves + // by reflecting on the same struct) panic(fmt.Errorf("error resolving path %v: %v has no field named %v", spec.path, v.Type(), field)) } @@ -144,7 +144,7 @@ func (p *Parser) printOption(w io.Writer, spec *spec) { // If spec.dest is not the zero value then a default value has been added. var v reflect.Value if spec.root >= 0 { - v = p.get(spec) + v = p.readable(spec) } if v.IsValid() { z := reflect.Zero(v.Type()) |