From 649bf79117e30895108b7782d62daafd07bc5e6e Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 22 May 2016 01:23:33 +0100 Subject: Use govendor --- vendor/github.com/BurntSushi/toml/lex.go | 866 +++++++++++++++++++++++++++++++ 1 file changed, 866 insertions(+) create mode 100644 vendor/github.com/BurntSushi/toml/lex.go (limited to 'vendor/github.com/BurntSushi/toml/lex.go') diff --git a/vendor/github.com/BurntSushi/toml/lex.go b/vendor/github.com/BurntSushi/toml/lex.go new file mode 100644 index 0000000..a016dc2 --- /dev/null +++ b/vendor/github.com/BurntSushi/toml/lex.go @@ -0,0 +1,866 @@ +package toml + +import ( + "fmt" + "strings" + "unicode" + "unicode/utf8" +) + +type itemType int + +const ( + itemError itemType = iota + itemNIL // used in the parser to indicate no type + itemEOF + itemText + itemString + itemRawString + itemMultilineString + itemRawMultilineString + itemBool + itemInteger + itemFloat + itemDatetime + itemArray // the start of an array + itemArrayEnd + itemTableStart + itemTableEnd + itemArrayTableStart + itemArrayTableEnd + itemKeyStart + itemCommentStart +) + +const ( + eof = 0 + tableStart = '[' + tableEnd = ']' + arrayTableStart = '[' + arrayTableEnd = ']' + tableSep = '.' + keySep = '=' + arrayStart = '[' + arrayEnd = ']' + arrayValTerm = ',' + commentStart = '#' + stringStart = '"' + stringEnd = '"' + rawStringStart = '\'' + rawStringEnd = '\'' +) + +type stateFn func(lx *lexer) stateFn + +type lexer struct { + input string + start int + pos int + width int + line int + state stateFn + items chan item + + // A stack of state functions used to maintain context. + // The idea is to reuse parts of the state machine in various places. + // For example, values can appear at the top level or within arbitrarily + // nested arrays. The last state on the stack is used after a value has + // been lexed. Similarly for comments. + stack []stateFn +} + +type item struct { + typ itemType + val string + line int +} + +func (lx *lexer) nextItem() item { + for { + select { + case item := <-lx.items: + return item + default: + lx.state = lx.state(lx) + } + } +} + +func lex(input string) *lexer { + lx := &lexer{ + input: input + "\n", + state: lexTop, + line: 1, + items: make(chan item, 10), + stack: make([]stateFn, 0, 10), + } + return lx +} + +func (lx *lexer) push(state stateFn) { + lx.stack = append(lx.stack, state) +} + +func (lx *lexer) pop() stateFn { + if len(lx.stack) == 0 { + return lx.errorf("BUG in lexer: no states to pop.") + } + last := lx.stack[len(lx.stack)-1] + lx.stack = lx.stack[0 : len(lx.stack)-1] + return last +} + +func (lx *lexer) current() string { + return lx.input[lx.start:lx.pos] +} + +func (lx *lexer) emit(typ itemType) { + lx.items <- item{typ, lx.current(), lx.line} + lx.start = lx.pos +} + +func (lx *lexer) emitTrim(typ itemType) { + lx.items <- item{typ, strings.TrimSpace(lx.current()), lx.line} + lx.start = lx.pos +} + +func (lx *lexer) next() (r rune) { + if lx.pos >= len(lx.input) { + lx.width = 0 + return eof + } + + if lx.input[lx.pos] == '\n' { + lx.line++ + } + r, lx.width = utf8.DecodeRuneInString(lx.input[lx.pos:]) + lx.pos += lx.width + return r +} + +// ignore skips over the pending input before this point. +func (lx *lexer) ignore() { + lx.start = lx.pos +} + +// backup steps back one rune. Can be called only once per call of next. +func (lx *lexer) backup() { + lx.pos -= lx.width + if lx.pos < len(lx.input) && lx.input[lx.pos] == '\n' { + lx.line-- + } +} + +// accept consumes the next rune if it's equal to `valid`. +func (lx *lexer) accept(valid rune) bool { + if lx.next() == valid { + return true + } + lx.backup() + return false +} + +// peek returns but does not consume the next rune in the input. +func (lx *lexer) peek() rune { + r := lx.next() + lx.backup() + return r +} + +// skip ignores all input that matches the given predicate. +func (lx *lexer) skip(pred func(rune) bool) { + for { + r := lx.next() + if pred(r) { + continue + } + lx.backup() + lx.ignore() + return + } +} + +// errorf stops all lexing by emitting an error and returning `nil`. +// Note that any value that is a character is escaped if it's a special +// character (new lines, tabs, etc.). +func (lx *lexer) errorf(format string, values ...interface{}) stateFn { + lx.items <- item{ + itemError, + fmt.Sprintf(format, values...), + lx.line, + } + return nil +} + +// lexTop consumes elements at the top level of TOML data. +func lexTop(lx *lexer) stateFn { + r := lx.next() + if isWhitespace(r) || isNL(r) { + return lexSkip(lx, lexTop) + } + + switch r { + case commentStart: + lx.push(lexTop) + return lexCommentStart + case tableStart: + return lexTableStart + case eof: + if lx.pos > lx.start { + return lx.errorf("Unexpected EOF.") + } + lx.emit(itemEOF) + return nil + } + + // At this point, the only valid item can be a key, so we back up + // and let the key lexer do the rest. + lx.backup() + lx.push(lexTopEnd) + return lexKeyStart +} + +// lexTopEnd is entered whenever a top-level item has been consumed. (A value +// or a table.) It must see only whitespace, and will turn back to lexTop +// upon a new line. If it sees EOF, it will quit the lexer successfully. +func lexTopEnd(lx *lexer) stateFn { + r := lx.next() + switch { + case r == commentStart: + // a comment will read to a new line for us. + lx.push(lexTop) + return lexCommentStart + case isWhitespace(r): + return lexTopEnd + case isNL(r): + lx.ignore() + return lexTop + case r == eof: + lx.ignore() + return lexTop + } + return lx.errorf("Expected a top-level item to end with a new line, "+ + "comment or EOF, but got %q instead.", r) +} + +// lexTable lexes the beginning of a table. Namely, it makes sure that +// it starts with a character other than '.' and ']'. +// It assumes that '[' has already been consumed. +// It also handles the case that this is an item in an array of tables. +// e.g., '[[name]]'. +func lexTableStart(lx *lexer) stateFn { + if lx.peek() == arrayTableStart { + lx.next() + lx.emit(itemArrayTableStart) + lx.push(lexArrayTableEnd) + } else { + lx.emit(itemTableStart) + lx.push(lexTableEnd) + } + return lexTableNameStart +} + +func lexTableEnd(lx *lexer) stateFn { + lx.emit(itemTableEnd) + return lexTopEnd +} + +func lexArrayTableEnd(lx *lexer) stateFn { + if r := lx.next(); r != arrayTableEnd { + return lx.errorf("Expected end of table array name delimiter %q, "+ + "but got %q instead.", arrayTableEnd, r) + } + lx.emit(itemArrayTableEnd) + return lexTopEnd +} + +func lexTableNameStart(lx *lexer) stateFn { + lx.skip(isWhitespace) + switch r := lx.peek(); { + case r == tableEnd || r == eof: + return lx.errorf("Unexpected end of table name. (Table names cannot " + + "be empty.)") + case r == tableSep: + return lx.errorf("Unexpected table separator. (Table names cannot " + + "be empty.)") + case r == stringStart || r == rawStringStart: + lx.ignore() + lx.push(lexTableNameEnd) + return lexValue // reuse string lexing + default: + return lexBareTableName + } +} + +// lexBareTableName lexes the name of a table. It assumes that at least one +// valid character for the table has already been read. +func lexBareTableName(lx *lexer) stateFn { + r := lx.next() + if isBareKeyChar(r) { + return lexBareTableName + } + lx.backup() + lx.emit(itemText) + return lexTableNameEnd +} + +// lexTableNameEnd reads the end of a piece of a table name, optionally +// consuming whitespace. +func lexTableNameEnd(lx *lexer) stateFn { + lx.skip(isWhitespace) + switch r := lx.next(); { + case isWhitespace(r): + return lexTableNameEnd + case r == tableSep: + lx.ignore() + return lexTableNameStart + case r == tableEnd: + return lx.pop() + default: + return lx.errorf("Expected '.' or ']' to end table name, but got %q "+ + "instead.", r) + } +} + +// lexKeyStart consumes a key name up until the first non-whitespace character. +// lexKeyStart will ignore whitespace. +func lexKeyStart(lx *lexer) stateFn { + r := lx.peek() + switch { + case r == keySep: + return lx.errorf("Unexpected key separator %q.", keySep) + case isWhitespace(r) || isNL(r): + lx.next() + return lexSkip(lx, lexKeyStart) + case r == stringStart || r == rawStringStart: + lx.ignore() + lx.emit(itemKeyStart) + lx.push(lexKeyEnd) + return lexValue // reuse string lexing + default: + lx.ignore() + lx.emit(itemKeyStart) + return lexBareKey + } +} + +// lexBareKey consumes the text of a bare key. Assumes that the first character +// (which is not whitespace) has not yet been consumed. +func lexBareKey(lx *lexer) stateFn { + switch r := lx.next(); { + case isBareKeyChar(r): + return lexBareKey + case isWhitespace(r): + lx.backup() + lx.emit(itemText) + return lexKeyEnd + case r == keySep: + lx.backup() + lx.emit(itemText) + return lexKeyEnd + default: + return lx.errorf("Bare keys cannot contain %q.", r) + } +} + +// lexKeyEnd consumes the end of a key and trims whitespace (up to the key +// separator). +func lexKeyEnd(lx *lexer) stateFn { + switch r := lx.next(); { + case r == keySep: + return lexSkip(lx, lexValue) + case isWhitespace(r): + return lexSkip(lx, lexKeyEnd) + default: + return lx.errorf("Expected key separator %q, but got %q instead.", + keySep, r) + } +} + +// lexValue starts the consumption of a value anywhere a value is expected. +// lexValue will ignore whitespace. +// After a value is lexed, the last state on the next is popped and returned. +func lexValue(lx *lexer) stateFn { + // We allow whitespace to precede a value, but NOT new lines. + // In array syntax, the array states are responsible for ignoring new + // lines. + r := lx.next() + switch { + case isWhitespace(r): + return lexSkip(lx, lexValue) + case isDigit(r): + lx.backup() // avoid an extra state and use the same as above + return lexNumberOrDateStart + } + switch r { + case arrayStart: + lx.ignore() + lx.emit(itemArray) + return lexArrayValue + case stringStart: + if lx.accept(stringStart) { + if lx.accept(stringStart) { + lx.ignore() // Ignore """ + return lexMultilineString + } + lx.backup() + } + lx.ignore() // ignore the '"' + return lexString + case rawStringStart: + if lx.accept(rawStringStart) { + if lx.accept(rawStringStart) { + lx.ignore() // Ignore """ + return lexMultilineRawString + } + lx.backup() + } + lx.ignore() // ignore the "'" + return lexRawString + case '+', '-': + return lexNumberStart + case '.': // special error case, be kind to users + return lx.errorf("Floats must start with a digit, not '.'.") + } + if unicode.IsLetter(r) { + // Be permissive here; lexBool will give a nice error if the + // user wrote something like + // x = foo + // (i.e. not 'true' or 'false' but is something else word-like.) + lx.backup() + return lexBool + } + return lx.errorf("Expected value but found %q instead.", r) +} + +// lexArrayValue consumes one value in an array. It assumes that '[' or ',' +// have already been consumed. All whitespace and new lines are ignored. +func lexArrayValue(lx *lexer) stateFn { + r := lx.next() + switch { + case isWhitespace(r) || isNL(r): + return lexSkip(lx, lexArrayValue) + case r == commentStart: + lx.push(lexArrayValue) + return lexCommentStart + case r == arrayValTerm: + return lx.errorf("Unexpected array value terminator %q.", + arrayValTerm) + case r == arrayEnd: + return lexArrayEnd + } + + lx.backup() + lx.push(lexArrayValueEnd) + return lexValue +} + +// lexArrayValueEnd consumes the cruft between values of an array. Namely, +// it ignores whitespace and expects either a ',' or a ']'. +func lexArrayValueEnd(lx *lexer) stateFn { + r := lx.next() + switch { + case isWhitespace(r) || isNL(r): + return lexSkip(lx, lexArrayValueEnd) + case r == commentStart: + lx.push(lexArrayValueEnd) + return lexCommentStart + case r == arrayValTerm: + lx.ignore() + return lexArrayValue // move on to the next value + case r == arrayEnd: + return lexArrayEnd + } + return lx.errorf("Expected an array value terminator %q or an array "+ + "terminator %q, but got %q instead.", arrayValTerm, arrayEnd, r) +} + +// lexArrayEnd finishes the lexing of an array. It assumes that a ']' has +// just been consumed. +func lexArrayEnd(lx *lexer) stateFn { + lx.ignore() + lx.emit(itemArrayEnd) + return lx.pop() +} + +// lexString consumes the inner contents of a string. It assumes that the +// beginning '"' has already been consumed and ignored. +func lexString(lx *lexer) stateFn { + r := lx.next() + switch { + case isNL(r): + return lx.errorf("Strings cannot contain new lines.") + case r == '\\': + lx.push(lexString) + return lexStringEscape + case r == stringEnd: + lx.backup() + lx.emit(itemString) + lx.next() + lx.ignore() + return lx.pop() + } + return lexString +} + +// lexMultilineString consumes the inner contents of a string. It assumes that +// the beginning '"""' has already been consumed and ignored. +func lexMultilineString(lx *lexer) stateFn { + r := lx.next() + switch { + case r == '\\': + return lexMultilineStringEscape + case r == stringEnd: + if lx.accept(stringEnd) { + if lx.accept(stringEnd) { + lx.backup() + lx.backup() + lx.backup() + lx.emit(itemMultilineString) + lx.next() + lx.next() + lx.next() + lx.ignore() + return lx.pop() + } + lx.backup() + } + } + return lexMultilineString +} + +// lexRawString consumes a raw string. Nothing can be escaped in such a string. +// It assumes that the beginning "'" has already been consumed and ignored. +func lexRawString(lx *lexer) stateFn { + r := lx.next() + switch { + case isNL(r): + return lx.errorf("Strings cannot contain new lines.") + case r == rawStringEnd: + lx.backup() + lx.emit(itemRawString) + lx.next() + lx.ignore() + return lx.pop() + } + return lexRawString +} + +// lexMultilineRawString consumes a raw string. Nothing can be escaped in such +// a string. It assumes that the beginning "'" has already been consumed and +// ignored. +func lexMultilineRawString(lx *lexer) stateFn { + r := lx.next() + switch { + case r == rawStringEnd: + if lx.accept(rawStringEnd) { + if lx.accept(rawStringEnd) { + lx.backup() + lx.backup() + lx.backup() + lx.emit(itemRawMultilineString) + lx.next() + lx.next() + lx.next() + lx.ignore() + return lx.pop() + } + lx.backup() + } + } + return lexMultilineRawString +} + +// lexMultilineStringEscape consumes an escaped character. It assumes that the +// preceding '\\' has already been consumed. +func lexMultilineStringEscape(lx *lexer) stateFn { + // Handle the special case first: + if isNL(lx.next()) { + return lexMultilineString + } else { + lx.backup() + lx.push(lexMultilineString) + return lexStringEscape(lx) + } +} + +func lexStringEscape(lx *lexer) stateFn { + r := lx.next() + switch r { + case 'b': + fallthrough + case 't': + fallthrough + case 'n': + fallthrough + case 'f': + fallthrough + case 'r': + fallthrough + case '"': + fallthrough + case '\\': + return lx.pop() + case 'u': + return lexShortUnicodeEscape + case 'U': + return lexLongUnicodeEscape + } + return lx.errorf("Invalid escape character %q. Only the following "+ + "escape characters are allowed: "+ + "\\b, \\t, \\n, \\f, \\r, \\\", \\/, \\\\, "+ + "\\uXXXX and \\UXXXXXXXX.", r) +} + +func lexShortUnicodeEscape(lx *lexer) stateFn { + var r rune + for i := 0; i < 4; i++ { + r = lx.next() + if !isHexadecimal(r) { + return lx.errorf("Expected four hexadecimal digits after '\\u', "+ + "but got '%s' instead.", lx.current()) + } + } + return lx.pop() +} + +func lexLongUnicodeEscape(lx *lexer) stateFn { + var r rune + for i := 0; i < 8; i++ { + r = lx.next() + if !isHexadecimal(r) { + return lx.errorf("Expected eight hexadecimal digits after '\\U', "+ + "but got '%s' instead.", lx.current()) + } + } + return lx.pop() +} + +// lexNumberOrDateStart consumes either an integer, a float, or datetime. +func lexNumberOrDateStart(lx *lexer) stateFn { + r := lx.next() + if isDigit(r) { + return lexNumberOrDate + } + switch r { + case '_': + return lexNumber + case 'e', 'E': + return lexFloat + case '.': + return lx.errorf("Floats must start with a digit, not '.'.") + } + return lx.errorf("Expected a digit but got %q.", r) +} + +// lexNumberOrDate consumes either an integer, float or datetime. +func lexNumberOrDate(lx *lexer) stateFn { + r := lx.next() + if isDigit(r) { + return lexNumberOrDate + } + switch r { + case '-': + return lexDatetime + case '_': + return lexNumber + case '.', 'e', 'E': + return lexFloat + } + + lx.backup() + lx.emit(itemInteger) + return lx.pop() +} + +// lexDatetime consumes a Datetime, to a first approximation. +// The parser validates that it matches one of the accepted formats. +func lexDatetime(lx *lexer) stateFn { + r := lx.next() + if isDigit(r) { + return lexDatetime + } + switch r { + case '-', 'T', ':', '.', 'Z': + return lexDatetime + } + + lx.backup() + lx.emit(itemDatetime) + return lx.pop() +} + +// lexNumberStart consumes either an integer or a float. It assumes that a sign +// has already been read, but that *no* digits have been consumed. +// lexNumberStart will move to the appropriate integer or float states. +func lexNumberStart(lx *lexer) stateFn { + // We MUST see a digit. Even floats have to start with a digit. + r := lx.next() + if !isDigit(r) { + if r == '.' { + return lx.errorf("Floats must start with a digit, not '.'.") + } else { + return lx.errorf("Expected a digit but got %q.", r) + } + } + return lexNumber +} + +// lexNumber consumes an integer or a float after seeing the first digit. +func lexNumber(lx *lexer) stateFn { + r := lx.next() + if isDigit(r) { + return lexNumber + } + switch r { + case '_': + return lexNumber + case '.', 'e', 'E': + return lexFloat + } + + lx.backup() + lx.emit(itemInteger) + return lx.pop() +} + +// lexFloat consumes the elements of a float. It allows any sequence of +// float-like characters, so floats emitted by the lexer are only a first +// approximation and must be validated by the parser. +func lexFloat(lx *lexer) stateFn { + r := lx.next() + if isDigit(r) { + return lexFloat + } + switch r { + case '_', '.', '-', '+', 'e', 'E': + return lexFloat + } + + lx.backup() + lx.emit(itemFloat) + return lx.pop() +} + +// lexBool consumes a bool string: 'true' or 'false. +func lexBool(lx *lexer) stateFn { + var rs []rune + for { + r := lx.next() + if r == eof || isWhitespace(r) || isNL(r) { + lx.backup() + break + } + rs = append(rs, r) + } + s := string(rs) + switch s { + case "true", "false": + lx.emit(itemBool) + return lx.pop() + } + return lx.errorf("Expected value but found %q instead.", s) +} + +// lexCommentStart begins the lexing of a comment. It will emit +// itemCommentStart and consume no characters, passing control to lexComment. +func lexCommentStart(lx *lexer) stateFn { + lx.ignore() + lx.emit(itemCommentStart) + return lexComment +} + +// lexComment lexes an entire comment. It assumes that '#' has been consumed. +// It will consume *up to* the first new line character, and pass control +// back to the last state on the stack. +func lexComment(lx *lexer) stateFn { + r := lx.peek() + if isNL(r) || r == eof { + lx.emit(itemText) + return lx.pop() + } + lx.next() + return lexComment +} + +// lexSkip ignores all slurped input and moves on to the next state. +func lexSkip(lx *lexer, nextState stateFn) stateFn { + return func(lx *lexer) stateFn { + lx.ignore() + return nextState + } +} + +// isWhitespace returns true if `r` is a whitespace character according +// to the spec. +func isWhitespace(r rune) bool { + return r == '\t' || r == ' ' +} + +func isNL(r rune) bool { + return r == '\n' || r == '\r' +} + +func isDigit(r rune) bool { + return r >= '0' && r <= '9' +} + +func isHexadecimal(r rune) bool { + return (r >= '0' && r <= '9') || + (r >= 'a' && r <= 'f') || + (r >= 'A' && r <= 'F') +} + +func isBareKeyChar(r rune) bool { + return (r >= 'A' && r <= 'Z') || + (r >= 'a' && r <= 'z') || + (r >= '0' && r <= '9') || + r == '_' || + r == '-' +} + +func (itype itemType) String() string { + switch itype { + case itemError: + return "Error" + case itemNIL: + return "NIL" + case itemEOF: + return "EOF" + case itemText: + return "Text" + case itemString: + return "String" + case itemRawString: + return "String" + case itemMultilineString: + return "String" + case itemRawMultilineString: + return "String" + case itemBool: + return "Bool" + case itemInteger: + return "Integer" + case itemFloat: + return "Float" + case itemDatetime: + return "DateTime" + case itemTableStart: + return "TableStart" + case itemTableEnd: + return "TableEnd" + case itemKeyStart: + return "KeyStart" + case itemArray: + return "Array" + case itemArrayEnd: + return "ArrayEnd" + case itemCommentStart: + return "CommentStart" + } + panic(fmt.Sprintf("BUG: Unknown type '%d'.", int(itype))) +} + +func (item item) String() string { + return fmt.Sprintf("(%s, %s)", item.typ.String(), item.val) +} -- cgit v1.2.3