61 lines
1.3 KiB
Go
61 lines
1.3 KiB
Go
package reflector
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import (
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"fmt"
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"strconv"
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)
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// ParseTag parses a golang struct tag into a map.
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func ParseTag(tag string) (map[string]string, error) {
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res := map[string]string{}
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// This code is copied/modified from: reflect/type.go:
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for tag != "" {
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// Skip leading space.
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i := 0
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for i < len(tag) && tag[i] == ' ' {
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i++
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}
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tag = tag[i:]
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if tag == "" {
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break
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}
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// Scan to colon. A space, a quote or a control character is a syntax error.
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// Strictly speaking, control chars include the range [0x7f, 0x9f], not just
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// [0x00, 0x1f], but in practice, we ignore the multi-byte control characters
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// as it is simpler to inspect the tag's bytes than the tag's runes.
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i = 0
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for i < len(tag) && tag[i] > ' ' && tag[i] != ':' && tag[i] != '"' && tag[i] != 0x7f {
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i++
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}
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if i == 0 || i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' {
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break
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}
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name := string(tag[:i])
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tag = tag[i+1:]
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// Scan quoted string to find value.
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i = 1
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for i < len(tag) && tag[i] != '"' {
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if tag[i] == '\\' {
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i++
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}
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i++
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}
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if i >= len(tag) {
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break
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}
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qvalue := string(tag[:i+1])
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tag = tag[i+1:]
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value, err := strconv.Unquote(qvalue)
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if err != nil {
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return nil, fmt.Errorf("Cannot unquote tag %s in %s: %s", name, tag, err.Error())
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}
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res[name] = value
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}
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return res, nil
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}
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