1 files changed, 451 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/hcl/json/scanner/scanner.go b/vendor/github.com/hashicorp/hcl/json/scanner/scanner.go
new file mode 100644
index 00000000..fe3f0f09
--- /dev/null
+++ b/vendor/github.com/hashicorp/hcl/json/scanner/scanner.go
@@ -0,0 +1,451 @@
+package scanner
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/hashicorp/hcl/json/token"
+)
+
+// eof represents a marker rune for the end of the reader.
+const eof = rune(0)
+
+// Scanner defines a lexical scanner
+type Scanner struct {
+	buf *bytes.Buffer // Source buffer for advancing and scanning
+	src []byte        // Source buffer for immutable access
+
+	// Source Position
+	srcPos  token.Pos // current position
+	prevPos token.Pos // previous position, used for peek() method
+
+	lastCharLen int // length of last character in bytes
+	lastLineLen int // length of last line in characters (for correct column reporting)
+
+	tokStart int // token text start position
+	tokEnd   int // token text end  position
+
+	// Error is called for each error encountered. If no Error
+	// function is set, the error is reported to os.Stderr.
+	Error func(pos token.Pos, msg string)
+
+	// ErrorCount is incremented by one for each error encountered.
+	ErrorCount int
+
+	// tokPos is the start position of most recently scanned token; set by
+	// Scan. The Filename field is always left untouched by the Scanner.  If
+	// an error is reported (via Error) and Position is invalid, the scanner is
+	// not inside a token.
+	tokPos token.Pos
+}
+
+// New creates and initializes a new instance of Scanner using src as
+// its source content.
+func New(src []byte) *Scanner {
+	// even though we accept a src, we read from a io.Reader compatible type
+	// (*bytes.Buffer). So in the future we might easily change it to streaming
+	// read.
+	b := bytes.NewBuffer(src)
+	s := &Scanner{
+		buf: b,
+		src: src,
+	}
+
+	// srcPosition always starts with 1
+	s.srcPos.Line = 1
+	return s
+}
+
+// next reads the next rune from the bufferred reader. Returns the rune(0) if
+// an error occurs (or io.EOF is returned).
+func (s *Scanner) next() rune {
+	ch, size, err := s.buf.ReadRune()
+	if err != nil {
+		// advance for error reporting
+		s.srcPos.Column++
+		s.srcPos.Offset += size
+		s.lastCharLen = size
+		return eof
+	}
+
+	if ch == utf8.RuneError && size == 1 {
+		s.srcPos.Column++
+		s.srcPos.Offset += size
+		s.lastCharLen = size
+		s.err("illegal UTF-8 encoding")
+		return ch
+	}
+
+	// remember last position
+	s.prevPos = s.srcPos
+
+	s.srcPos.Column++
+	s.lastCharLen = size
+	s.srcPos.Offset += size
+
+	if ch == '\n' {
+		s.srcPos.Line++
+		s.lastLineLen = s.srcPos.Column
+		s.srcPos.Column = 0
+	}
+
+	// debug
+	// fmt.Printf("ch: %q, offset:column: %d:%d\n", ch, s.srcPos.Offset, s.srcPos.Column)
+	return ch
+}
+
+// unread unreads the previous read Rune and updates the source position
+func (s *Scanner) unread() {
+	if err := s.buf.UnreadRune(); err != nil {
+		panic(err) // this is user fault, we should catch it
+	}
+	s.srcPos = s.prevPos // put back last position
+}
+
+// peek returns the next rune without advancing the reader.
+func (s *Scanner) peek() rune {
+	peek, _, err := s.buf.ReadRune()
+	if err != nil {
+		return eof
+	}
+
+	s.buf.UnreadRune()
+	return peek
+}
+
+// Scan scans the next token and returns the token.
+func (s *Scanner) Scan() token.Token {
+	ch := s.next()
+
+	// skip white space
+	for isWhitespace(ch) {
+		ch = s.next()
+	}
+
+	var tok token.Type
+
+	// token text markings
+	s.tokStart = s.srcPos.Offset - s.lastCharLen
+
+	// token position, initial next() is moving the offset by one(size of rune
+	// actually), though we are interested with the starting point
+	s.tokPos.Offset = s.srcPos.Offset - s.lastCharLen
+	if s.srcPos.Column > 0 {
+		// common case: last character was not a '\n'
+		s.tokPos.Line = s.srcPos.Line
+		s.tokPos.Column = s.srcPos.Column
+	} else {
+		// last character was a '\n'
+		// (we cannot be at the beginning of the source
+		// since we have called next() at least once)
+		s.tokPos.Line = s.srcPos.Line - 1
+		s.tokPos.Column = s.lastLineLen
+	}
+
+	switch {
+	case isLetter(ch):
+		lit := s.scanIdentifier()
+		if lit == "true" || lit == "false" {
+			tok = token.BOOL
+		} else if lit == "null" {
+			tok = token.NULL
+		} else {
+			s.err("illegal char")
+		}
+	case isDecimal(ch):
+		tok = s.scanNumber(ch)
+	default:
+		switch ch {
+		case eof:
+			tok = token.EOF
+		case '"':
+			tok = token.STRING
+			s.scanString()
+		case '.':
+			tok = token.PERIOD
+			ch = s.peek()
+			if isDecimal(ch) {
+				tok = token.FLOAT
+				ch = s.scanMantissa(ch)
+				ch = s.scanExponent(ch)
+			}
+		case '[':
+			tok = token.LBRACK
+		case ']':
+			tok = token.RBRACK
+		case '{':
+			tok = token.LBRACE
+		case '}':
+			tok = token.RBRACE
+		case ',':
+			tok = token.COMMA
+		case ':':
+			tok = token.COLON
+		case '-':
+			if isDecimal(s.peek()) {
+				ch := s.next()
+				tok = s.scanNumber(ch)
+			} else {
+				s.err("illegal char")
+			}
+		default:
+			s.err("illegal char: " + string(ch))
+		}
+	}
+
+	// finish token ending
+	s.tokEnd = s.srcPos.Offset
+
+	// create token literal
+	var tokenText string
+	if s.tokStart >= 0 {
+		tokenText = string(s.src[s.tokStart:s.tokEnd])
+	}
+	s.tokStart = s.tokEnd // ensure idempotency of tokenText() call
+
+	return token.Token{
+		Type: tok,
+		Pos:  s.tokPos,
+		Text: tokenText,
+	}
+}
+
+// scanNumber scans a HCL number definition starting with the given rune
+func (s *Scanner) scanNumber(ch rune) token.Type {
+	zero := ch == '0'
+	pos := s.srcPos
+
+	s.scanMantissa(ch)
+	ch = s.next() // seek forward
+	if ch == 'e' || ch == 'E' {
+		ch = s.scanExponent(ch)
+		return token.FLOAT
+	}
+
+	if ch == '.' {
+		ch = s.scanFraction(ch)
+		if ch == 'e' || ch == 'E' {
+			ch = s.next()
+			ch = s.scanExponent(ch)
+		}
+		return token.FLOAT
+	}
+
+	if ch != eof {
+		s.unread()
+	}
+
+	// If we have a larger number and this is zero, error
+	if zero && pos != s.srcPos {
+		s.err("numbers cannot start with 0")
+	}
+
+	return token.NUMBER
+}
+
+// scanMantissa scans the mantissa beginning from the rune. It returns the next
+// non decimal rune. It's used to determine wheter it's a fraction or exponent.
+func (s *Scanner) scanMantissa(ch rune) rune {
+	scanned := false
+	for isDecimal(ch) {
+		ch = s.next()
+		scanned = true
+	}
+
+	if scanned && ch != eof {
+		s.unread()
+	}
+	return ch
+}
+
+// scanFraction scans the fraction after the '.' rune
+func (s *Scanner) scanFraction(ch rune) rune {
+	if ch == '.' {
+		ch = s.peek() // we peek just to see if we can move forward
+		ch = s.scanMantissa(ch)
+	}
+	return ch
+}
+
+// scanExponent scans the remaining parts of an exponent after the 'e' or 'E'
+// rune.
+func (s *Scanner) scanExponent(ch rune) rune {
+	if ch == 'e' || ch == 'E' {
+		ch = s.next()
+		if ch == '-' || ch == '+' {
+			ch = s.next()
+		}
+		ch = s.scanMantissa(ch)
+	}
+	return ch
+}
+
+// scanString scans a quoted string
+func (s *Scanner) scanString() {
+	braces := 0
+	for {
+		// '"' opening already consumed
+		// read character after quote
+		ch := s.next()
+
+		if ch == '\n' || ch < 0 || ch == eof {
+			s.err("literal not terminated")
+			return
+		}
+
+		if ch == '"' {
+			break
+		}
+
+		// If we're going into a ${} then we can ignore quotes for awhile
+		if braces == 0 && ch == '$' && s.peek() == '{' {
+			braces++
+			s.next()
+		} else if braces > 0 && ch == '{' {
+			braces++
+		}
+		if braces > 0 && ch == '}' {
+			braces--
+		}
+
+		if ch == '\\' {
+			s.scanEscape()
+		}
+	}
+
+	return
+}
+
+// scanEscape scans an escape sequence
+func (s *Scanner) scanEscape() rune {
+	// http://en.cppreference.com/w/cpp/language/escape
+	ch := s.next() // read character after '/'
+	switch ch {
+	case 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', '"':
+		// nothing to do
+	case '0', '1', '2', '3', '4', '5', '6', '7':
+		// octal notation
+		ch = s.scanDigits(ch, 8, 3)
+	case 'x':
+		// hexademical notation
+		ch = s.scanDigits(s.next(), 16, 2)
+	case 'u':
+		// universal character name
+		ch = s.scanDigits(s.next(), 16, 4)
+	case 'U':
+		// universal character name
+		ch = s.scanDigits(s.next(), 16, 8)
+	default:
+		s.err("illegal char escape")
+	}
+	return ch
+}
+
+// scanDigits scans a rune with the given base for n times. For example an
+// octal notation \184 would yield in scanDigits(ch, 8, 3)
+func (s *Scanner) scanDigits(ch rune, base, n int) rune {
+	for n > 0 && digitVal(ch) < base {
+		ch = s.next()
+		n--
+	}
+	if n > 0 {
+		s.err("illegal char escape")
+	}
+
+	// we scanned all digits, put the last non digit char back
+	s.unread()
+	return ch
+}
+
+// scanIdentifier scans an identifier and returns the literal string
+func (s *Scanner) scanIdentifier() string {
+	offs := s.srcPos.Offset - s.lastCharLen
+	ch := s.next()
+	for isLetter(ch) || isDigit(ch) || ch == '-' {
+		ch = s.next()
+	}
+
+	if ch != eof {
+		s.unread() // we got identifier, put back latest char
+	}
+
+	return string(s.src[offs:s.srcPos.Offset])
+}
+
+// recentPosition returns the position of the character immediately after the
+// character or token returned by the last call to Scan.
+func (s *Scanner) recentPosition() (pos token.Pos) {
+	pos.Offset = s.srcPos.Offset - s.lastCharLen
+	switch {
+	case s.srcPos.Column > 0:
+		// common case: last character was not a '\n'
+		pos.Line = s.srcPos.Line
+		pos.Column = s.srcPos.Column
+	case s.lastLineLen > 0:
+		// last character was a '\n'
+		// (we cannot be at the beginning of the source
+		// since we have called next() at least once)
+		pos.Line = s.srcPos.Line - 1
+		pos.Column = s.lastLineLen
+	default:
+		// at the beginning of the source
+		pos.Line = 1
+		pos.Column = 1
+	}
+	return
+}
+
+// err prints the error of any scanning to s.Error function. If the function is
+// not defined, by default it prints them to os.Stderr
+func (s *Scanner) err(msg string) {
+	s.ErrorCount++
+	pos := s.recentPosition()
+
+	if s.Error != nil {
+		s.Error(pos, msg)
+		return
+	}
+
+	fmt.Fprintf(os.Stderr, "%s: %s\n", pos, msg)
+}
+
+// isHexadecimal returns true if the given rune is a letter
+func isLetter(ch rune) bool {
+	return 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' || ch == '_' || ch >= 0x80 && unicode.IsLetter(ch)
+}
+
+// isHexadecimal returns true if the given rune is a decimal digit
+func isDigit(ch rune) bool {
+	return '0' <= ch && ch <= '9' || ch >= 0x80 && unicode.IsDigit(ch)
+}
+
+// isHexadecimal returns true if the given rune is a decimal number
+func isDecimal(ch rune) bool {
+	return '0' <= ch && ch <= '9'
+}
+
+// isHexadecimal returns true if the given rune is an hexadecimal number
+func isHexadecimal(ch rune) bool {
+	return '0' <= ch && ch <= '9' || 'a' <= ch && ch <= 'f' || 'A' <= ch && ch <= 'F'
+}
+
+// isWhitespace returns true if the rune is a space, tab, newline or carriage return
+func isWhitespace(ch rune) bool {
+	return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r'
+}
+
+// digitVal returns the integer value of a given octal,decimal or hexadecimal rune
+func digitVal(ch rune) int {
+	switch {
+	case '0' <= ch && ch <= '9':
+		return int(ch - '0')
+	case 'a' <= ch && ch <= 'f':
+		return int(ch - 'a' + 10)
+	case 'A' <= ch && ch <= 'F':
+		return int(ch - 'A' + 10)
+	}
+	return 16 // larger than any legal digit val
+}