63 lines
1.8 KiB
Go
63 lines
1.8 KiB
Go
package parsekit
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import (
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"bytes"
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"strconv"
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"strings"
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)
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// stringBuffer is a string buffer implementation, which is used by the parser
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// to efficiently accumulate runes from the input and eventually turn these
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// into a string, either literal or interpreted.
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type stringBuffer struct {
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buffer bytes.Buffer
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}
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// reset resets the string buffer, in order to build a new string.
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func (b *stringBuffer) reset() *stringBuffer {
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b.buffer.Reset()
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return b
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}
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// writeString adds the runes of the input string to the string buffer.
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func (b *stringBuffer) writeString(s string) *stringBuffer {
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for _, r := range s {
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b.writeRune(r)
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}
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return b
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}
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// writeRune adds a single rune to the string buffer.
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func (b *stringBuffer) writeRune(r rune) *stringBuffer {
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b.buffer.WriteRune(r)
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return b
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}
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// asLiteralString returns the string buffer as a literal string.
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// Literal means that no escape sequences are processed.
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func (b *stringBuffer) asLiteralString() string {
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return b.buffer.String()
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}
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// asInterpretedString returns the string in its interpreted form.
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// Interpreted means that escape sequences are handled in the way that Go would
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// have, had it been inside double quotes. It translates for example escape
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// sequences like "\n", "\t", \uXXXX" and "\UXXXXXXXX" into their string
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// representations.
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// Since the input might contain invalid escape sequences, this method
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// also returns an error. When an error is returned, the returned string will
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// contain the string as far as it could be interpreted.
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func (b *stringBuffer) asInterpretedString() (string, error) {
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var sb strings.Builder
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tail := b.buffer.String()
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for len(tail) > 0 {
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r, _, newtail, err := strconv.UnquoteChar(tail, '"')
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if err != nil {
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return sb.String(), err
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}
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tail = newtail
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sb.WriteRune(r)
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}
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return sb.String(), nil
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}
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