58 lines
1.3 KiB
Go
58 lines
1.3 KiB
Go
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package pointerstructure
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import (
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"fmt"
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"strings"
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)
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// Parse parses a pointer from the input string. The input string
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// is expected to follow the format specified by RFC 6901: '/'-separated
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// parts. Each part can contain escape codes to contain '/' or '~'.
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func Parse(input string) (*Pointer, error) {
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// Special case the empty case
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if input == "" {
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return &Pointer{}, nil
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}
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// We expect the first character to be "/"
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if input[0] != '/' {
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return nil, fmt.Errorf(
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"parse Go pointer %q: first char must be '/'", input)
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}
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// Trim out the first slash so we don't have to +1 every index
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input = input[1:]
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// Parse out all the parts
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var parts []string
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lastSlash := -1
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for i, r := range input {
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if r == '/' {
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parts = append(parts, input[lastSlash+1:i])
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lastSlash = i
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}
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}
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// Add last part
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parts = append(parts, input[lastSlash+1:])
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// Process each part for string replacement
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for i, p := range parts {
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// Replace ~1 followed by ~0 as specified by the RFC
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parts[i] = strings.Replace(
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strings.Replace(p, "~1", "/", -1), "~0", "~", -1)
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}
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return &Pointer{Parts: parts}, nil
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}
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// MustParse is like Parse but panics if the input cannot be parsed.
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func MustParse(input string) *Pointer {
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p, err := Parse(input)
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if err != nil {
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panic(err)
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}
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return p
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}
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