1 files changed, 407 insertions, 0 deletions
diff --git a/vendor/github.com/magiconair/properties/lex.go b/vendor/github.com/magiconair/properties/lex.go
new file mode 100644
index 00000000..c63fcc60
--- /dev/null
+++ b/vendor/github.com/magiconair/properties/lex.go
@@ -0,0 +1,407 @@
+// Copyright 2017 Frank Schroeder. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// Parts of the lexer are from the template/text/parser package
+// For these parts the following applies:
+//
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file of the go 1.2
+// distribution.
+
+package properties
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+// item represents a token or text string returned from the scanner.
+type item struct {
+	typ itemType // The type of this item.
+	pos int      // The starting position, in bytes, of this item in the input string.
+	val string   // The value of this item.
+}
+
+func (i item) String() string {
+	switch {
+	case i.typ == itemEOF:
+		return "EOF"
+	case i.typ == itemError:
+		return i.val
+	case len(i.val) > 10:
+		return fmt.Sprintf("%.10q...", i.val)
+	}
+	return fmt.Sprintf("%q", i.val)
+}
+
+// itemType identifies the type of lex items.
+type itemType int
+
+const (
+	itemError itemType = iota // error occurred; value is text of error
+	itemEOF
+	itemKey     // a key
+	itemValue   // a value
+	itemComment // a comment
+)
+
+// defines a constant for EOF
+const eof = -1
+
+// permitted whitespace characters space, FF and TAB
+const whitespace = " \f\t"
+
+// stateFn represents the state of the scanner as a function that returns the next state.
+type stateFn func(*lexer) stateFn
+
+// lexer holds the state of the scanner.
+type lexer struct {
+	input   string    // the string being scanned
+	state   stateFn   // the next lexing function to enter
+	pos     int       // current position in the input
+	start   int       // start position of this item
+	width   int       // width of last rune read from input
+	lastPos int       // position of most recent item returned by nextItem
+	runes   []rune    // scanned runes for this item
+	items   chan item // channel of scanned items
+}
+
+// next returns the next rune in the input.
+func (l *lexer) next() rune {
+	if l.pos >= len(l.input) {
+		l.width = 0
+		return eof
+	}
+	r, w := utf8.DecodeRuneInString(l.input[l.pos:])
+	l.width = w
+	l.pos += l.width
+	return r
+}
+
+// peek returns but does not consume the next rune in the input.
+func (l *lexer) peek() rune {
+	r := l.next()
+	l.backup()
+	return r
+}
+
+// backup steps back one rune. Can only be called once per call of next.
+func (l *lexer) backup() {
+	l.pos -= l.width
+}
+
+// emit passes an item back to the client.
+func (l *lexer) emit(t itemType) {
+	i := item{t, l.start, string(l.runes)}
+	l.items <- i
+	l.start = l.pos
+	l.runes = l.runes[:0]
+}
+
+// ignore skips over the pending input before this point.
+func (l *lexer) ignore() {
+	l.start = l.pos
+}
+
+// appends the rune to the current value
+func (l *lexer) appendRune(r rune) {
+	l.runes = append(l.runes, r)
+}
+
+// accept consumes the next rune if it's from the valid set.
+func (l *lexer) accept(valid string) bool {
+	if strings.ContainsRune(valid, l.next()) {
+		return true
+	}
+	l.backup()
+	return false
+}
+
+// acceptRun consumes a run of runes from the valid set.
+func (l *lexer) acceptRun(valid string) {
+	for strings.ContainsRune(valid, l.next()) {
+	}
+	l.backup()
+}
+
+// acceptRunUntil consumes a run of runes up to a terminator.
+func (l *lexer) acceptRunUntil(term rune) {
+	for term != l.next() {
+	}
+	l.backup()
+}
+
+// hasText returns true if the current parsed text is not empty.
+func (l *lexer) isNotEmpty() bool {
+	return l.pos > l.start
+}
+
+// lineNumber reports which line we're on, based on the position of
+// the previous item returned by nextItem. Doing it this way
+// means we don't have to worry about peek double counting.
+func (l *lexer) lineNumber() int {
+	return 1 + strings.Count(l.input[:l.lastPos], "\n")
+}
+
+// errorf returns an error token and terminates the scan by passing
+// back a nil pointer that will be the next state, terminating l.nextItem.
+func (l *lexer) errorf(format string, args ...interface{}) stateFn {
+	l.items <- item{itemError, l.start, fmt.Sprintf(format, args...)}
+	return nil
+}
+
+// nextItem returns the next item from the input.
+func (l *lexer) nextItem() item {
+	i := <-l.items
+	l.lastPos = i.pos
+	return i
+}
+
+// lex creates a new scanner for the input string.
+func lex(input string) *lexer {
+	l := &lexer{
+		input: input,
+		items: make(chan item),
+		runes: make([]rune, 0, 32),
+	}
+	go l.run()
+	return l
+}
+
+// run runs the state machine for the lexer.
+func (l *lexer) run() {
+	for l.state = lexBeforeKey(l); l.state != nil; {
+		l.state = l.state(l)
+	}
+}
+
+// state functions
+
+// lexBeforeKey scans until a key begins.
+func lexBeforeKey(l *lexer) stateFn {
+	switch r := l.next(); {
+	case isEOF(r):
+		l.emit(itemEOF)
+		return nil
+
+	case isEOL(r):
+		l.ignore()
+		return lexBeforeKey
+
+	case isComment(r):
+		return lexComment
+
+	case isWhitespace(r):
+		l.ignore()
+		return lexBeforeKey
+
+	default:
+		l.backup()
+		return lexKey
+	}
+}
+
+// lexComment scans a comment line. The comment character has already been scanned.
+func lexComment(l *lexer) stateFn {
+	l.acceptRun(whitespace)
+	l.ignore()
+	for {
+		switch r := l.next(); {
+		case isEOF(r):
+			l.ignore()
+			l.emit(itemEOF)
+			return nil
+		case isEOL(r):
+			l.emit(itemComment)
+			return lexBeforeKey
+		default:
+			l.appendRune(r)
+		}
+	}
+}
+
+// lexKey scans the key up to a delimiter
+func lexKey(l *lexer) stateFn {
+	var r rune
+
+Loop:
+	for {
+		switch r = l.next(); {
+
+		case isEscape(r):
+			err := l.scanEscapeSequence()
+			if err != nil {
+				return l.errorf(err.Error())
+			}
+
+		case isEndOfKey(r):
+			l.backup()
+			break Loop
+
+		case isEOF(r):
+			break Loop
+
+		default:
+			l.appendRune(r)
+		}
+	}
+
+	if len(l.runes) > 0 {
+		l.emit(itemKey)
+	}
+
+	if isEOF(r) {
+		l.emit(itemEOF)
+		return nil
+	}
+
+	return lexBeforeValue
+}
+
+// lexBeforeValue scans the delimiter between key and value.
+// Leading and trailing whitespace is ignored.
+// We expect to be just after the key.
+func lexBeforeValue(l *lexer) stateFn {
+	l.acceptRun(whitespace)
+	l.accept(":=")
+	l.acceptRun(whitespace)
+	l.ignore()
+	return lexValue
+}
+
+// lexValue scans text until the end of the line. We expect to be just after the delimiter.
+func lexValue(l *lexer) stateFn {
+	for {
+		switch r := l.next(); {
+		case isEscape(r):
+			if isEOL(l.peek()) {
+				l.next()
+				l.acceptRun(whitespace)
+			} else {
+				err := l.scanEscapeSequence()
+				if err != nil {
+					return l.errorf(err.Error())
+				}
+			}
+
+		case isEOL(r):
+			l.emit(itemValue)
+			l.ignore()
+			return lexBeforeKey
+
+		case isEOF(r):
+			l.emit(itemValue)
+			l.emit(itemEOF)
+			return nil
+
+		default:
+			l.appendRune(r)
+		}
+	}
+}
+
+// scanEscapeSequence scans either one of the escaped characters
+// or a unicode literal. We expect to be after the escape character.
+func (l *lexer) scanEscapeSequence() error {
+	switch r := l.next(); {
+
+	case isEscapedCharacter(r):
+		l.appendRune(decodeEscapedCharacter(r))
+		return nil
+
+	case atUnicodeLiteral(r):
+		return l.scanUnicodeLiteral()
+
+	case isEOF(r):
+		return fmt.Errorf("premature EOF")
+
+	// silently drop the escape character and append the rune as is
+	default:
+		l.appendRune(r)
+		return nil
+	}
+}
+
+// scans a unicode literal in the form \uXXXX. We expect to be after the \u.
+func (l *lexer) scanUnicodeLiteral() error {
+	// scan the digits
+	d := make([]rune, 4)
+	for i := 0; i < 4; i++ {
+		d[i] = l.next()
+		if d[i] == eof || !strings.ContainsRune("0123456789abcdefABCDEF", d[i]) {
+			return fmt.Errorf("invalid unicode literal")
+		}
+	}
+
+	// decode the digits into a rune
+	r, err := strconv.ParseInt(string(d), 16, 0)
+	if err != nil {
+		return err
+	}
+
+	l.appendRune(rune(r))
+	return nil
+}
+
+// decodeEscapedCharacter returns the unescaped rune. We expect to be after the escape character.
+func decodeEscapedCharacter(r rune) rune {
+	switch r {
+	case 'f':
+		return '\f'
+	case 'n':
+		return '\n'
+	case 'r':
+		return '\r'
+	case 't':
+		return '\t'
+	default:
+		return r
+	}
+}
+
+// atUnicodeLiteral reports whether we are at a unicode literal.
+// The escape character has already been consumed.
+func atUnicodeLiteral(r rune) bool {
+	return r == 'u'
+}
+
+// isComment reports whether we are at the start of a comment.
+func isComment(r rune) bool {
+	return r == '#' || r == '!'
+}
+
+// isEndOfKey reports whether the rune terminates the current key.
+func isEndOfKey(r rune) bool {
+	return strings.ContainsRune(" \f\t\r\n:=", r)
+}
+
+// isEOF reports whether we are at EOF.
+func isEOF(r rune) bool {
+	return r == eof
+}
+
+// isEOL reports whether we are at a new line character.
+func isEOL(r rune) bool {
+	return r == '\n' || r == '\r'
+}
+
+// isEscape reports whether the rune is the escape character which
+// prefixes unicode literals and other escaped characters.
+func isEscape(r rune) bool {
+	return r == '\\'
+}
+
+// isEscapedCharacter reports whether we are at one of the characters that need escaping.
+// The escape character has already been consumed.
+func isEscapedCharacter(r rune) bool {
+	return strings.ContainsRune(" :=fnrt", r)
+}
+
+// isWhitespace reports whether the rune is a whitespace character.
+func isWhitespace(r rune) bool {
+	return strings.ContainsRune(whitespace, r)
+}