From 649bf79117e30895108b7782d62daafd07bc5e6e Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 22 May 2016 01:23:33 +0100 Subject: Use govendor --- .../hashicorp/hcl/hcl/scanner/scanner.go | 629 +++++++++++++++++++++ 1 file changed, 629 insertions(+) create mode 100644 vendor/github.com/hashicorp/hcl/hcl/scanner/scanner.go (limited to 'vendor/github.com/hashicorp/hcl/hcl/scanner/scanner.go') diff --git a/vendor/github.com/hashicorp/hcl/hcl/scanner/scanner.go b/vendor/github.com/hashicorp/hcl/hcl/scanner/scanner.go new file mode 100644 index 0000000..a3f34a7 --- /dev/null +++ b/vendor/github.com/hashicorp/hcl/hcl/scanner/scanner.go @@ -0,0 +1,629 @@ +// Package scanner implements a scanner for HCL (HashiCorp Configuration +// Language) source text. +package scanner + +import ( + "bytes" + "fmt" + "os" + "regexp" + "unicode" + "unicode/utf8" + + "github.com/hashicorp/hcl/hcl/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): + tok = token.IDENT + lit := s.scanIdentifier() + if lit == "true" || lit == "false" { + tok = token.BOOL + } + case isDecimal(ch): + tok = s.scanNumber(ch) + default: + switch ch { + case eof: + tok = token.EOF + case '"': + tok = token.STRING + s.scanString() + case '#', '/': + tok = token.COMMENT + s.scanComment(ch) + case '.': + tok = token.PERIOD + ch = s.peek() + if isDecimal(ch) { + tok = token.FLOAT + ch = s.scanMantissa(ch) + ch = s.scanExponent(ch) + } + case '<': + tok = token.HEREDOC + s.scanHeredoc() + case '[': + tok = token.LBRACK + case ']': + tok = token.RBRACK + case '{': + tok = token.LBRACE + case '}': + tok = token.RBRACE + case ',': + tok = token.COMMA + case '=': + tok = token.ASSIGN + case '+': + tok = token.ADD + case '-': + if isDecimal(s.peek()) { + ch := s.next() + tok = s.scanNumber(ch) + } else { + tok = token.SUB + } + default: + s.err("illegal char") + } + } + + // 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, + } +} + +func (s *Scanner) scanComment(ch rune) { + // single line comments + if ch == '#' || (ch == '/' && s.peek() != '*') { + ch = s.next() + for ch != '\n' && ch >= 0 && ch != eof { + ch = s.next() + } + if ch != eof && ch >= 0 { + s.unread() + } + return + } + + // be sure we get the character after /* This allows us to find comment's + // that are not erminated + if ch == '/' { + s.next() + ch = s.next() // read character after "/*" + } + + // look for /* - style comments + for { + if ch < 0 || ch == eof { + s.err("comment not terminated") + break + } + + ch0 := ch + ch = s.next() + if ch0 == '*' && ch == '/' { + break + } + } +} + +// scanNumber scans a HCL number definition starting with the given rune +func (s *Scanner) scanNumber(ch rune) token.Type { + if ch == '0' { + // check for hexadecimal, octal or float + ch = s.next() + if ch == 'x' || ch == 'X' { + // hexadecimal + ch = s.next() + found := false + for isHexadecimal(ch) { + ch = s.next() + found = true + } + + if !found { + s.err("illegal hexadecimal number") + } + + if ch != eof { + s.unread() + } + + return token.NUMBER + } + + // now it's either something like: 0421(octal) or 0.1231(float) + illegalOctal := false + for isDecimal(ch) { + ch = s.next() + if ch == '8' || ch == '9' { + // this is just a possibility. For example 0159 is illegal, but + // 0159.23 is valid. So we mark a possible illegal octal. If + // the next character is not a period, we'll print the error. + illegalOctal = true + } + } + + 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 illegalOctal { + s.err("illegal octal number") + } + + if ch != eof { + s.unread() + } + return token.NUMBER + } + + 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() + } + return token.NUMBER +} + +// scanMantissa scans the mantissa begining 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 +} + +// scanHeredoc scans a heredoc string +func (s *Scanner) scanHeredoc() { + // Scan the second '<' in example: '<= len(identBytes) && identRegexp.Match(s.src[lineStart:s.srcPos.Offset-s.lastCharLen]) { + break + } + + // Not an anchor match, record the start of a new line + lineStart = s.srcPos.Offset + } + + if ch == eof { + s.err("heredoc not terminated") + return + } + } + + return +} + +// 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 == '"' && braces == 0 { + 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 == '.' { + 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) +} + +// isDigit 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) +} + +// isDecimal 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 +} -- cgit v1.2.3