40 lines
1.0 KiB
Go
40 lines
1.0 KiB
Go
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package q
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import (
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"errors"
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"reflect"
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)
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// ErrUnknownField is returned when an unknown field is passed.
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var ErrUnknownField = errors.New("unknown field")
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type fieldMatcherDelegate struct {
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FieldMatcher
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Field string
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}
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// NewFieldMatcher creates a Matcher for a given field.
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func NewFieldMatcher(field string, fm FieldMatcher) Matcher {
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return fieldMatcherDelegate{Field: field, FieldMatcher: fm}
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}
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// FieldMatcher can be used in NewFieldMatcher as a simple way to create the
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// most common Matcher: A Matcher that evaluates one field's value.
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// For more complex scenarios, implement the Matcher interface directly.
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type FieldMatcher interface {
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MatchField(v interface{}) (bool, error)
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}
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func (r fieldMatcherDelegate) Match(i interface{}) (bool, error) {
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v := reflect.Indirect(reflect.ValueOf(i))
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return r.MatchValue(&v)
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}
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func (r fieldMatcherDelegate) MatchValue(v *reflect.Value) (bool, error) {
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field := v.FieldByName(r.Field)
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if !field.IsValid() {
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return false, ErrUnknownField
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}
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return r.MatchField(field.Interface())
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}
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