mirror of https://github.com/vbatts/go-mtree.git
90 lines
2.6 KiB
Go
90 lines
2.6 KiB
Go
package mtree
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import "unicode"
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// Vis is a wrapper of the C implementation of the function vis, which encodes
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// a character with a particular format/style.
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// For most use-cases use DefaultVisFlags.
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func Vis(src string, flags VisFlag) (string, error) {
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return vis(src, flags)
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}
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// DefaultVisFlags are the typical flags used for encoding strings in mtree
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// manifests.
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var DefaultVisFlags = VisWhite | VisOctal | VisGlob
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// VisFlag sets the extent of charactures to be encoded
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type VisFlag int
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// flags for encoding
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const (
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// to select alternate encoding format
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VisOctal VisFlag = 0x01 // use octal \ddd format
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VisCstyle VisFlag = 0x02 // use \[nrft0..] where appropriate
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// to alter set of characters encoded (default is to encode all non-graphic
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// except space, tab, and newline).
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VisSp VisFlag = 0x04 // also encode space
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VisTab VisFlag = 0x08 // also encode tab
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VisNl VisFlag = 0x10 // also encode newline
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VisWhite VisFlag = (VisSp | VisTab | VisNl)
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VisSafe VisFlag = 0x20 // only encode "unsafe" characters
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// other
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VisNoSlash VisFlag = 0x40 // inhibit printing '\'
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VisHttpstyle VisFlag = 0x80 // http-style escape % HEX HEX
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VisGlob VisFlag = 0x100 // encode glob(3) magics
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)
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// errors used in the tokenized decoding strings
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const (
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// unvis return codes
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unvisValid unvisErr = 1 // character valid
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unvisValidPush unvisErr = 2 // character valid, push back passed char
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unvisNochar unvisErr = 3 // valid sequence, no character produced
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unvisErrSynbad unvisErr = -1 // unrecognized escape sequence
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unvisErrUnrecoverable unvisErr = -2 // decoder in unknown state (unrecoverable)
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unvisNone unvisErr = 0
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// unvisEnd means there are no more characters
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unvisEnd VisFlag = 1 // no more characters
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)
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// unvisErr are the return conditions for Unvis
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type unvisErr int
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func (ue unvisErr) Error() string {
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switch ue {
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case unvisValid:
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return "character valid"
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case unvisValidPush:
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return "character valid, push back passed char"
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case unvisNochar:
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return "valid sequence, no character produced"
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case unvisErrSynbad:
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return "unrecognized escape sequence"
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case unvisErrUnrecoverable:
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return "decoder in unknown state (unrecoverable)"
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}
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return "Unknown Error"
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}
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func ishex(r rune) bool {
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lr := unicode.ToLower(r)
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return (lr >= '0' && lr <= '9') || (lr >= 'a' && lr <= 'f')
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}
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func isoctal(r rune) bool {
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return r <= '7' && r >= '0'
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}
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// the ctype isgraph is "any printable character except space"
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func isgraph(r rune) bool {
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return unicode.IsPrint(r) && !unicode.IsSpace(r)
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}
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func isalnum(r rune) bool {
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return unicode.IsNumber(r) || unicode.IsLetter(r)
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}
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