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author | Wim <wim@42.be> | 2018-03-04 23:46:13 +0100 |
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committer | Wim <wim@42.be> | 2018-03-04 23:46:13 +0100 |
commit | 25a72113b122f984c904b24c4af23a1cba1eff45 (patch) | |
tree | f0fb7067d7c958d60ac964afa5b8d5fb79ebc339 /vendor/github.com/pelletier/go-toml/query/lexer.go | |
parent | 79c4ad5015bd2be47b32141c6d53f0d128bf865b (diff) | |
download | matterbridge-msglm-25a72113b122f984c904b24c4af23a1cba1eff45.tar.gz matterbridge-msglm-25a72113b122f984c904b24c4af23a1cba1eff45.tar.bz2 matterbridge-msglm-25a72113b122f984c904b24c4af23a1cba1eff45.zip |
Add vendor files for spf13/viper
Diffstat (limited to 'vendor/github.com/pelletier/go-toml/query/lexer.go')
-rw-r--r-- | vendor/github.com/pelletier/go-toml/query/lexer.go | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/vendor/github.com/pelletier/go-toml/query/lexer.go b/vendor/github.com/pelletier/go-toml/query/lexer.go new file mode 100644 index 00000000..2dc31940 --- /dev/null +++ b/vendor/github.com/pelletier/go-toml/query/lexer.go @@ -0,0 +1,357 @@ +// TOML JSONPath lexer. +// +// Written using the principles developed by Rob Pike in +// http://www.youtube.com/watch?v=HxaD_trXwRE + +package query + +import ( + "fmt" + "github.com/pelletier/go-toml" + "strconv" + "strings" + "unicode/utf8" +) + +// Lexer state function +type queryLexStateFn func() queryLexStateFn + +// Lexer definition +type queryLexer struct { + input string + start int + pos int + width int + tokens chan token + depth int + line int + col int + stringTerm string +} + +func (l *queryLexer) run() { + for state := l.lexVoid; state != nil; { + state = state() + } + close(l.tokens) +} + +func (l *queryLexer) nextStart() { + // iterate by runes (utf8 characters) + // search for newlines and advance line/col counts + for i := l.start; i < l.pos; { + r, width := utf8.DecodeRuneInString(l.input[i:]) + if r == '\n' { + l.line++ + l.col = 1 + } else { + l.col++ + } + i += width + } + // advance start position to next token + l.start = l.pos +} + +func (l *queryLexer) emit(t tokenType) { + l.tokens <- token{ + Position: toml.Position{Line: l.line, Col: l.col}, + typ: t, + val: l.input[l.start:l.pos], + } + l.nextStart() +} + +func (l *queryLexer) emitWithValue(t tokenType, value string) { + l.tokens <- token{ + Position: toml.Position{Line: l.line, Col: l.col}, + typ: t, + val: value, + } + l.nextStart() +} + +func (l *queryLexer) next() rune { + if l.pos >= len(l.input) { + l.width = 0 + return eof + } + var r rune + r, l.width = utf8.DecodeRuneInString(l.input[l.pos:]) + l.pos += l.width + return r +} + +func (l *queryLexer) ignore() { + l.nextStart() +} + +func (l *queryLexer) backup() { + l.pos -= l.width +} + +func (l *queryLexer) errorf(format string, args ...interface{}) queryLexStateFn { + l.tokens <- token{ + Position: toml.Position{Line: l.line, Col: l.col}, + typ: tokenError, + val: fmt.Sprintf(format, args...), + } + return nil +} + +func (l *queryLexer) peek() rune { + r := l.next() + l.backup() + return r +} + +func (l *queryLexer) accept(valid string) bool { + if strings.ContainsRune(valid, l.next()) { + return true + } + l.backup() + return false +} + +func (l *queryLexer) follow(next string) bool { + return strings.HasPrefix(l.input[l.pos:], next) +} + +func (l *queryLexer) lexVoid() queryLexStateFn { + for { + next := l.peek() + switch next { + case '$': + l.pos++ + l.emit(tokenDollar) + continue + case '.': + if l.follow("..") { + l.pos += 2 + l.emit(tokenDotDot) + } else { + l.pos++ + l.emit(tokenDot) + } + continue + case '[': + l.pos++ + l.emit(tokenLeftBracket) + continue + case ']': + l.pos++ + l.emit(tokenRightBracket) + continue + case ',': + l.pos++ + l.emit(tokenComma) + continue + case '*': + l.pos++ + l.emit(tokenStar) + continue + case '(': + l.pos++ + l.emit(tokenLeftParen) + continue + case ')': + l.pos++ + l.emit(tokenRightParen) + continue + case '?': + l.pos++ + l.emit(tokenQuestion) + continue + case ':': + l.pos++ + l.emit(tokenColon) + continue + case '\'': + l.ignore() + l.stringTerm = string(next) + return l.lexString + case '"': + l.ignore() + l.stringTerm = string(next) + return l.lexString + } + + if isSpace(next) { + l.next() + l.ignore() + continue + } + + if isAlphanumeric(next) { + return l.lexKey + } + + if next == '+' || next == '-' || isDigit(next) { + return l.lexNumber + } + + if l.next() == eof { + break + } + + return l.errorf("unexpected char: '%v'", next) + } + l.emit(tokenEOF) + return nil +} + +func (l *queryLexer) lexKey() queryLexStateFn { + for { + next := l.peek() + if !isAlphanumeric(next) { + l.emit(tokenKey) + return l.lexVoid + } + + if l.next() == eof { + break + } + } + l.emit(tokenEOF) + return nil +} + +func (l *queryLexer) lexString() queryLexStateFn { + l.pos++ + l.ignore() + growingString := "" + + for { + if l.follow(l.stringTerm) { + l.emitWithValue(tokenString, growingString) + l.pos++ + l.ignore() + return l.lexVoid + } + + if l.follow("\\\"") { + l.pos++ + growingString += "\"" + } else if l.follow("\\'") { + l.pos++ + growingString += "'" + } else if l.follow("\\n") { + l.pos++ + growingString += "\n" + } else if l.follow("\\b") { + l.pos++ + growingString += "\b" + } else if l.follow("\\f") { + l.pos++ + growingString += "\f" + } else if l.follow("\\/") { + l.pos++ + growingString += "/" + } else if l.follow("\\t") { + l.pos++ + growingString += "\t" + } else if l.follow("\\r") { + l.pos++ + growingString += "\r" + } else if l.follow("\\\\") { + l.pos++ + growingString += "\\" + } else if l.follow("\\u") { + l.pos += 2 + code := "" + for i := 0; i < 4; i++ { + c := l.peek() + l.pos++ + if !isHexDigit(c) { + return l.errorf("unfinished unicode escape") + } + code = code + string(c) + } + l.pos-- + intcode, err := strconv.ParseInt(code, 16, 32) + if err != nil { + return l.errorf("invalid unicode escape: \\u" + code) + } + growingString += string(rune(intcode)) + } else if l.follow("\\U") { + l.pos += 2 + code := "" + for i := 0; i < 8; i++ { + c := l.peek() + l.pos++ + if !isHexDigit(c) { + return l.errorf("unfinished unicode escape") + } + code = code + string(c) + } + l.pos-- + intcode, err := strconv.ParseInt(code, 16, 32) + if err != nil { + return l.errorf("invalid unicode escape: \\u" + code) + } + growingString += string(rune(intcode)) + } else if l.follow("\\") { + l.pos++ + return l.errorf("invalid escape sequence: \\" + string(l.peek())) + } else { + growingString += string(l.peek()) + } + + if l.next() == eof { + break + } + } + + return l.errorf("unclosed string") +} + +func (l *queryLexer) lexNumber() queryLexStateFn { + l.ignore() + if !l.accept("+") { + l.accept("-") + } + pointSeen := false + digitSeen := false + for { + next := l.next() + if next == '.' { + if pointSeen { + return l.errorf("cannot have two dots in one float") + } + if !isDigit(l.peek()) { + return l.errorf("float cannot end with a dot") + } + pointSeen = true + } else if isDigit(next) { + digitSeen = true + } else { + l.backup() + break + } + if pointSeen && !digitSeen { + return l.errorf("cannot start float with a dot") + } + } + + if !digitSeen { + return l.errorf("no digit in that number") + } + if pointSeen { + l.emit(tokenFloat) + } else { + l.emit(tokenInteger) + } + return l.lexVoid +} + +// Entry point +func lexQuery(input string) chan token { + l := &queryLexer{ + input: input, + tokens: make(chan token), + line: 1, + col: 1, + } + go l.run() + return l.tokens +} |