66 lines
1.8 KiB
Go
66 lines
1.8 KiB
Go
package toml
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import (
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"fmt"
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"reflect"
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"strings"
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)
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const fieldTagName = "toml"
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// fieldCache maps normalized field names to their position in a struct.
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type fieldCache struct {
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named map[string]fieldInfo // fields with an explicit name in tag
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auto map[string]fieldInfo // fields with auto-assigned normalized names
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}
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type fieldInfo struct {
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index []int
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name string
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ignored bool
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}
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func makeFieldCache(cfg *Config, rt reflect.Type) fieldCache {
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named, auto := make(map[string]fieldInfo), make(map[string]fieldInfo)
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for i := 0; i < rt.NumField(); i++ {
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ft := rt.Field(i)
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// skip unexported fields
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if ft.PkgPath != "" && !ft.Anonymous {
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continue
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}
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col, _ := extractTag(ft.Tag.Get(fieldTagName))
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info := fieldInfo{index: ft.Index, name: ft.Name, ignored: col == "-"}
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if col == "" || col == "-" {
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auto[cfg.NormFieldName(rt, ft.Name)] = info
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} else {
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named[col] = info
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}
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}
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return fieldCache{named, auto}
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}
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func (fc fieldCache) findField(cfg *Config, rv reflect.Value, name string) (reflect.Value, string, error) {
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info, found := fc.named[name]
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if !found {
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info, found = fc.auto[cfg.NormFieldName(rv.Type(), name)]
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}
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if !found {
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if cfg.MissingField == nil {
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return reflect.Value{}, "", fmt.Errorf("field corresponding to `%s' is not defined in %v", name, rv.Type())
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} else {
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return reflect.Value{}, "", cfg.MissingField(rv.Type(), name)
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}
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} else if info.ignored {
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return reflect.Value{}, "", fmt.Errorf("field corresponding to `%s' in %v cannot be set through TOML", name, rv.Type())
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}
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return rv.FieldByIndex(info.index), info.name, nil
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}
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func extractTag(tag string) (col, rest string) {
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tags := strings.SplitN(tag, ",", 2)
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if len(tags) == 2 {
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return strings.TrimSpace(tags[0]), strings.TrimSpace(tags[1])
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}
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return strings.TrimSpace(tags[0]), ""
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}
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