53 lines
1.1 KiB
Go
53 lines
1.1 KiB
Go
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// Package strquote provides a function for formatting a string as a
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// Cap'n Proto string literal.
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package strquote
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// Append appends a Cap'n Proto string literal of s to buf.
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func Append(buf []byte, s []byte) []byte {
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buf = append(buf, '"')
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last := 0
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for i, b := range s {
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if !needsEscape(b) {
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continue
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}
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buf = append(buf, s[last:i]...)
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switch b {
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case '\a':
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buf = append(buf, '\\', 'a')
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case '\b':
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buf = append(buf, '\\', 'b')
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case '\f':
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buf = append(buf, '\\', 'f')
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case '\n':
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buf = append(buf, '\\', 'n')
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case '\r':
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buf = append(buf, '\\', 'r')
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case '\t':
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buf = append(buf, '\\', 't')
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case '\v':
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buf = append(buf, '\\', 'v')
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case '\'':
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buf = append(buf, '\\', '\'')
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case '"':
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buf = append(buf, '\\', '"')
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case '\\':
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buf = append(buf, '\\', '\\')
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default:
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buf = append(buf, '\\', 'x', hexDigit(b/16), hexDigit(b%16))
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}
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last = i + 1
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}
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buf = append(buf, s[last:]...)
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buf = append(buf, '"')
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return buf
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}
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func needsEscape(b byte) bool {
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return b < 0x20 || b >= 0x7f
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}
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func hexDigit(b byte) byte {
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const digits = "0123456789abcdef"
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return digits[b]
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}
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