diff options
Diffstat (limited to 'vendor/github.com/BurntSushi/toml/lex.go')
| -rw-r--r-- | vendor/github.com/BurntSushi/toml/lex.go | 768 |
1 files changed, 524 insertions, 244 deletions
diff --git a/vendor/github.com/BurntSushi/toml/lex.go b/vendor/github.com/BurntSushi/toml/lex.go index e0a742a88..28ed4dd35 100644 --- a/vendor/github.com/BurntSushi/toml/lex.go +++ b/vendor/github.com/BurntSushi/toml/lex.go @@ -2,6 +2,8 @@ package toml import ( "fmt" + "reflect" + "runtime" "strings" "unicode" "unicode/utf8" @@ -29,33 +31,20 @@ const ( itemArrayTableStart itemArrayTableEnd itemKeyStart + itemKeyEnd itemCommentStart itemInlineTableStart itemInlineTableEnd ) -const ( - eof = 0 - comma = ',' - tableStart = '[' - tableEnd = ']' - arrayTableStart = '[' - arrayTableEnd = ']' - tableSep = '.' - keySep = '=' - arrayStart = '[' - arrayEnd = ']' - commentStart = '#' - stringStart = '"' - stringEnd = '"' - rawStringStart = '\'' - rawStringEnd = '\'' - inlineTableStart = '{' - inlineTableEnd = '}' -) +const eof = 0 type stateFn func(lx *lexer) stateFn +func (p Position) String() string { + return fmt.Sprintf("at line %d; start %d; length %d", p.Line, p.Start, p.Len) +} + type lexer struct { input string start int @@ -64,26 +53,26 @@ type lexer struct { state stateFn items chan item - // Allow for backing up up to three runes. - // This is necessary because TOML contains 3-rune tokens (""" and '''). - prevWidths [3]int - nprev int // how many of prevWidths are in use - // If we emit an eof, we can still back up, but it is not OK to call - // next again. - atEOF bool + // Allow for backing up up to 4 runes. This is necessary because TOML + // contains 3-rune tokens (""" and '''). + prevWidths [4]int + nprev int // how many of prevWidths are in use + atEOF bool // If we emit an eof, we can still back up, but it is not OK to call next again. // 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. + // + // 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 + typ itemType + val string + err error + pos Position } func (lx *lexer) nextItem() item { @@ -93,6 +82,7 @@ func (lx *lexer) nextItem() item { return item default: lx.state = lx.state(lx) + //fmt.Printf(" STATE %-24s current: %-10s stack: %s\n", lx.state, lx.current(), lx.stack) } } } @@ -101,9 +91,9 @@ func lex(input string) *lexer { lx := &lexer{ input: input, state: lexTop, - line: 1, items: make(chan item, 10), stack: make([]stateFn, 0, 10), + line: 1, } return lx } @@ -125,19 +115,36 @@ func (lx *lexer) current() string { return lx.input[lx.start:lx.pos] } +func (lx lexer) getPos() Position { + p := Position{ + Line: lx.line, + Start: lx.start, + Len: lx.pos - lx.start, + } + if p.Len <= 0 { + p.Len = 1 + } + return p +} + func (lx *lexer) emit(typ itemType) { - lx.items <- item{typ, lx.current(), lx.line} + // Needed for multiline strings ending with an incomplete UTF-8 sequence. + if lx.start > lx.pos { + lx.error(errLexUTF8{lx.input[lx.pos]}) + return + } + lx.items <- item{typ: typ, pos: lx.getPos(), val: lx.current()} lx.start = lx.pos } func (lx *lexer) emitTrim(typ itemType) { - lx.items <- item{typ, strings.TrimSpace(lx.current()), lx.line} + lx.items <- item{typ: typ, pos: lx.getPos(), val: strings.TrimSpace(lx.current())} lx.start = lx.pos } func (lx *lexer) next() (r rune) { if lx.atEOF { - panic("next called after EOF") + panic("BUG in lexer: next called after EOF") } if lx.pos >= len(lx.input) { lx.atEOF = true @@ -147,12 +154,25 @@ func (lx *lexer) next() (r rune) { if lx.input[lx.pos] == '\n' { lx.line++ } + lx.prevWidths[3] = lx.prevWidths[2] lx.prevWidths[2] = lx.prevWidths[1] lx.prevWidths[1] = lx.prevWidths[0] - if lx.nprev < 3 { + if lx.nprev < 4 { lx.nprev++ } + r, w := utf8.DecodeRuneInString(lx.input[lx.pos:]) + if r == utf8.RuneError { + lx.error(errLexUTF8{lx.input[lx.pos]}) + return utf8.RuneError + } + + // Note: don't use peek() here, as this calls next(). + if isControl(r) || (r == '\r' && (len(lx.input)-1 == lx.pos || lx.input[lx.pos+1] != '\n')) { + lx.errorControlChar(r) + return utf8.RuneError + } + lx.prevWidths[0] = w lx.pos += w return r @@ -163,19 +183,21 @@ func (lx *lexer) ignore() { lx.start = lx.pos } -// backup steps back one rune. Can be called only twice between calls to next. +// backup steps back one rune. Can be called 4 times between calls to next. func (lx *lexer) backup() { if lx.atEOF { lx.atEOF = false return } if lx.nprev < 1 { - panic("backed up too far") + panic("BUG in lexer: backed up too far") } w := lx.prevWidths[0] lx.prevWidths[0] = lx.prevWidths[1] lx.prevWidths[1] = lx.prevWidths[2] + lx.prevWidths[2] = lx.prevWidths[3] lx.nprev-- + lx.pos -= w if lx.pos < len(lx.input) && lx.input[lx.pos] == '\n' { lx.line-- @@ -211,18 +233,58 @@ func (lx *lexer) skip(pred func(rune) bool) { } } -// errorf stops all lexing by emitting an error and returning `nil`. +// error 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 (newlines, tabs, etc.). +func (lx *lexer) error(err error) stateFn { + if lx.atEOF { + return lx.errorPrevLine(err) + } + lx.items <- item{typ: itemError, pos: lx.getPos(), err: err} + return nil +} + +// errorfPrevline is like error(), but sets the position to the last column of +// the previous line. +// +// This is so that unexpected EOF or NL errors don't show on a new blank line. +func (lx *lexer) errorPrevLine(err error) stateFn { + pos := lx.getPos() + pos.Line-- + pos.Len = 1 + pos.Start = lx.pos - 1 + lx.items <- item{typ: itemError, pos: pos, err: err} + return nil +} + +// errorPos is like error(), but allows explicitly setting the position. +func (lx *lexer) errorPos(start, length int, err error) stateFn { + pos := lx.getPos() + pos.Start = start + pos.Len = length + lx.items <- item{typ: itemError, pos: pos, err: err} + return nil +} + +// errorf is like error, and creates a new error. func (lx *lexer) errorf(format string, values ...interface{}) stateFn { - lx.items <- item{ - itemError, - fmt.Sprintf(format, values...), - lx.line, + if lx.atEOF { + pos := lx.getPos() + pos.Line-- + pos.Len = 1 + pos.Start = lx.pos - 1 + lx.items <- item{typ: itemError, pos: pos, err: fmt.Errorf(format, values...)} + return nil } + lx.items <- item{typ: itemError, pos: lx.getPos(), err: fmt.Errorf(format, values...)} return nil } +func (lx *lexer) errorControlChar(cc rune) stateFn { + return lx.errorPos(lx.pos-1, 1, errLexControl{cc}) +} + // lexTop consumes elements at the top level of TOML data. func lexTop(lx *lexer) stateFn { r := lx.next() @@ -230,10 +292,10 @@ func lexTop(lx *lexer) stateFn { return lexSkip(lx, lexTop) } switch r { - case commentStart: + case '#': lx.push(lexTop) return lexCommentStart - case tableStart: + case '[': return lexTableStart case eof: if lx.pos > lx.start { @@ -256,7 +318,7 @@ func lexTop(lx *lexer) stateFn { func lexTopEnd(lx *lexer) stateFn { r := lx.next() switch { - case r == commentStart: + case r == '#': // a comment will read to a newline for us. lx.push(lexTop) return lexCommentStart @@ -269,8 +331,9 @@ func lexTopEnd(lx *lexer) stateFn { lx.emit(itemEOF) return nil } - return lx.errorf("expected a top-level item to end with a newline, "+ - "comment, or EOF, but got %q instead", r) + return lx.errorf( + "expected a top-level item to end with a newline, comment, or EOF, but got %q instead", + r) } // lexTable lexes the beginning of a table. Namely, it makes sure that @@ -279,7 +342,7 @@ func lexTopEnd(lx *lexer) stateFn { // 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 { + if lx.peek() == '[' { lx.next() lx.emit(itemArrayTableStart) lx.push(lexArrayTableEnd) @@ -296,9 +359,8 @@ func lexTableEnd(lx *lexer) stateFn { } 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) + if r := lx.next(); r != ']' { + return lx.errorf("expected end of table array name delimiter ']', but got %q instead", r) } lx.emit(itemArrayTableEnd) return lexTopEnd @@ -307,31 +369,18 @@ func lexArrayTableEnd(lx *lexer) stateFn { 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: + case r == ']' || r == eof: + return lx.errorf("unexpected end of table name (table names cannot be empty)") + case r == '.': + return lx.errorf("unexpected table separator (table names cannot be empty)") + case r == '"' || r == '\'': lx.ignore() lx.push(lexTableNameEnd) - return lexValue // reuse string lexing + return lexQuotedName 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.push(lexTableNameEnd) + return lexBareName } - lx.backup() - lx.emit(itemText) - return lexTableNameEnd } // lexTableNameEnd reads the end of a piece of a table name, optionally @@ -341,69 +390,107 @@ func lexTableNameEnd(lx *lexer) stateFn { switch r := lx.next(); { case isWhitespace(r): return lexTableNameEnd - case r == tableSep: + case r == '.': lx.ignore() return lexTableNameStart - case r == tableEnd: + case r == ']': return lx.pop() default: - return lx.errorf("expected '.' or ']' to end table name, "+ - "but got %q instead", r) + 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() +// lexBareName lexes one part of a key or table. +// +// It assumes that at least one valid character for the table has already been +// read. +// +// Lexes only one part, e.g. only 'a' inside 'a.b'. +func lexBareName(lx *lexer) stateFn { + r := lx.next() + if isBareKeyChar(r) { + return lexBareName + } + lx.backup() + lx.emit(itemText) + return lx.pop() +} + +// lexBareName lexes one part of a key or table. +// +// It assumes that at least one valid character for the table has already been +// read. +// +// Lexes only one part, e.g. only '"a"' inside '"a".b'. +func lexQuotedName(lx *lexer) stateFn { + r := lx.next() 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 + case isWhitespace(r): + return lexSkip(lx, lexValue) + case r == '"': + lx.ignore() // ignore the '"' + return lexString + case r == '\'': + lx.ignore() // ignore the "'" + return lexRawString + case r == eof: + return lx.errorf("unexpected EOF; expected value") default: + return lx.errorf("expected value but found %q instead", r) + } +} + +// lexKeyStart consumes all key parts until a '='. +func lexKeyStart(lx *lexer) stateFn { + lx.skip(isWhitespace) + switch r := lx.peek(); { + case r == '=' || r == eof: + return lx.errorf("unexpected '=': key name appears blank") + case r == '.': + return lx.errorf("unexpected '.': keys cannot start with a '.'") + case r == '"' || r == '\'': lx.ignore() + fallthrough + default: // Bare key lx.emit(itemKeyStart) - return lexBareKey + return lexKeyNameStart } } -// 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 +func lexKeyNameStart(lx *lexer) stateFn { + lx.skip(isWhitespace) + switch r := lx.peek(); { + case r == '=' || r == eof: + return lx.errorf("unexpected '='") + case r == '.': + return lx.errorf("unexpected '.'") + case r == '"' || r == '\'': + lx.ignore() + lx.push(lexKeyEnd) + return lexQuotedName default: - return lx.errorf("bare keys cannot contain %q", r) + lx.push(lexKeyEnd) + return lexBareName } } // lexKeyEnd consumes the end of a key and trims whitespace (up to the key // separator). func lexKeyEnd(lx *lexer) stateFn { + lx.skip(isWhitespace) switch r := lx.next(); { - case r == keySep: - return lexSkip(lx, lexValue) case isWhitespace(r): return lexSkip(lx, lexKeyEnd) + case r == eof: + return lx.errorf("unexpected EOF; expected key separator '='") + case r == '.': + lx.ignore() + return lexKeyNameStart + case r == '=': + lx.emit(itemKeyEnd) + return lexSkip(lx, lexValue) default: - return lx.errorf("expected key separator %q, but got %q instead", - keySep, r) + return lx.errorf("expected '.' or '=', but got %q instead", r) } } @@ -422,17 +509,17 @@ func lexValue(lx *lexer) stateFn { return lexNumberOrDateStart } switch r { - case arrayStart: + case '[': lx.ignore() lx.emit(itemArray) return lexArrayValue - case inlineTableStart: + case '{': lx.ignore() lx.emit(itemInlineTableStart) return lexInlineTableValue - case stringStart: - if lx.accept(stringStart) { - if lx.accept(stringStart) { + case '"': + if lx.accept('"') { + if lx.accept('"') { lx.ignore() // Ignore """ return lexMultilineString } @@ -440,9 +527,9 @@ func lexValue(lx *lexer) stateFn { } lx.ignore() // ignore the '"' return lexString - case rawStringStart: - if lx.accept(rawStringStart) { - if lx.accept(rawStringStart) { + case '\'': + if lx.accept('\'') { + if lx.accept('\'') { lx.ignore() // Ignore """ return lexMultilineRawString } @@ -450,10 +537,15 @@ func lexValue(lx *lexer) stateFn { } 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 '.'") + case 'i', 'n': + if (lx.accept('n') && lx.accept('f')) || (lx.accept('a') && lx.accept('n')) { + lx.emit(itemFloat) + return lx.pop() + } + case '-', '+': + return lexDecimalNumberStart } if unicode.IsLetter(r) { // Be permissive here; lexBool will give a nice error if the @@ -463,6 +555,9 @@ func lexValue(lx *lexer) stateFn { lx.backup() return lexBool } + if r == eof { + return lx.errorf("unexpected EOF; expected value") + } return lx.errorf("expected value but found %q instead", r) } @@ -473,14 +568,12 @@ func lexArrayValue(lx *lexer) stateFn { switch { case isWhitespace(r) || isNL(r): return lexSkip(lx, lexArrayValue) - case r == commentStart: + case r == '#': lx.push(lexArrayValue) return lexCommentStart - case r == comma: + case r == ',': return lx.errorf("unexpected comma") - case r == arrayEnd: - // NOTE(caleb): The spec isn't clear about whether you can have - // a trailing comma or not, so we'll allow it. + case r == ']': return lexArrayEnd } @@ -493,23 +586,20 @@ func lexArrayValue(lx *lexer) stateFn { // the next value (or the end of the array): it ignores whitespace and newlines // and expects either a ',' or a ']'. func lexArrayValueEnd(lx *lexer) stateFn { - r := lx.next() - switch { + switch r := lx.next(); { case isWhitespace(r) || isNL(r): return lexSkip(lx, lexArrayValueEnd) - case r == commentStart: + case r == '#': lx.push(lexArrayValueEnd) return lexCommentStart - case r == comma: + case r == ',': lx.ignore() return lexArrayValue // move on to the next value - case r == arrayEnd: + case r == ']': return lexArrayEnd + default: + return lx.errorf("expected a comma (',') or array terminator (']'), but got %s", runeOrEOF(r)) } - return lx.errorf( - "expected a comma or array terminator %q, but got %q instead", - arrayEnd, r, - ) } // lexArrayEnd finishes the lexing of an array. @@ -528,13 +618,13 @@ func lexInlineTableValue(lx *lexer) stateFn { case isWhitespace(r): return lexSkip(lx, lexInlineTableValue) case isNL(r): - return lx.errorf("newlines not allowed within inline tables") - case r == commentStart: + return lx.errorPrevLine(errLexInlineTableNL{}) + case r == '#': lx.push(lexInlineTableValue) return lexCommentStart - case r == comma: + case r == ',': return lx.errorf("unexpected comma") - case r == inlineTableEnd: + case r == '}': return lexInlineTableEnd } lx.backup() @@ -546,23 +636,33 @@ func lexInlineTableValue(lx *lexer) stateFn { // key/value pair and the next pair (or the end of the table): // it ignores whitespace and expects either a ',' or a '}'. func lexInlineTableValueEnd(lx *lexer) stateFn { - r := lx.next() - switch { + switch r := lx.next(); { case isWhitespace(r): return lexSkip(lx, lexInlineTableValueEnd) case isNL(r): - return lx.errorf("newlines not allowed within inline tables") - case r == commentStart: + return lx.errorPrevLine(errLexInlineTableNL{}) + case r == '#': lx.push(lexInlineTableValueEnd) return lexCommentStart - case r == comma: + case r == ',': lx.ignore() + lx.skip(isWhitespace) + if lx.peek() == '}' { + return lx.errorf("trailing comma not allowed in inline tables") + } return lexInlineTableValue - case r == inlineTableEnd: + case r == '}': return lexInlineTableEnd + default: + return lx.errorf("expected a comma or an inline table terminator '}', but got %s instead", runeOrEOF(r)) } - return lx.errorf("expected a comma or an inline table terminator %q, "+ - "but got %q instead", inlineTableEnd, r) +} + +func runeOrEOF(r rune) string { + if r == eof { + return "end of file" + } + return "'" + string(r) + "'" } // lexInlineTableEnd finishes the lexing of an inline table. @@ -579,13 +679,13 @@ func lexString(lx *lexer) stateFn { r := lx.next() switch { case r == eof: - return lx.errorf("unexpected EOF") + return lx.errorf(`unexpected EOF; expected '"'`) case isNL(r): - return lx.errorf("strings cannot contain newlines") + return lx.errorPrevLine(errLexStringNL{}) case r == '\\': lx.push(lexString) return lexStringEscape - case r == stringEnd: + case r == '"': lx.backup() lx.emit(itemString) lx.next() @@ -598,19 +698,47 @@ func lexString(lx *lexer) stateFn { // lexMultilineString consumes the inner contents of a string. It assumes that // the beginning '"""' has already been consumed and ignored. func lexMultilineString(lx *lexer) stateFn { - switch lx.next() { + r := lx.next() + switch r { + default: + return lexMultilineString case eof: - return lx.errorf("unexpected EOF") + return lx.errorf(`unexpected EOF; expected '"""'`) case '\\': return lexMultilineStringEscape - case stringEnd: - if lx.accept(stringEnd) { - if lx.accept(stringEnd) { - lx.backup() + case '"': + /// Found " → try to read two more "". + if lx.accept('"') { + if lx.accept('"') { + /// Peek ahead: the string can contain " and "", including at the + /// end: """str""""" + /// 6 or more at the end, however, is an error. + if lx.peek() == '"' { + /// Check if we already lexed 5 's; if so we have 6 now, and + /// that's just too many man! + /// + /// Second check is for the edge case: + /// + /// two quotes allowed. + /// vv + /// """lol \"""""" + /// ^^ ^^^---- closing three + /// escaped + /// + /// But ugly, but it works + if strings.HasSuffix(lx.current(), `"""""`) && !strings.HasSuffix(lx.current(), `\"""""`) { + return lx.errorf(`unexpected '""""""'`) + } + lx.backup() + lx.backup() + return lexMultilineString + } + + lx.backup() /// backup: don't include the """ in the item. lx.backup() lx.backup() lx.emit(itemMultilineString) - lx.next() + lx.next() /// Read over ''' again and discard it. lx.next() lx.next() lx.ignore() @@ -618,8 +746,8 @@ func lexMultilineString(lx *lexer) stateFn { } lx.backup() } + return lexMultilineString } - return lexMultilineString } // lexRawString consumes a raw string. Nothing can be escaped in such a string. @@ -627,35 +755,54 @@ func lexMultilineString(lx *lexer) stateFn { func lexRawString(lx *lexer) stateFn { r := lx.next() switch { + default: + return lexRawString case r == eof: - return lx.errorf("unexpected EOF") + return lx.errorf(`unexpected EOF; expected "'"`) case isNL(r): - return lx.errorf("strings cannot contain newlines") - case r == rawStringEnd: + return lx.errorPrevLine(errLexStringNL{}) + case r == '\'': 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 { - switch lx.next() { + r := lx.next() + switch r { + default: + return lexMultilineRawString case eof: - return lx.errorf("unexpected EOF") - case rawStringEnd: - if lx.accept(rawStringEnd) { - if lx.accept(rawStringEnd) { - lx.backup() + return lx.errorf(`unexpected EOF; expected "'''"`) + case '\'': + /// Found ' → try to read two more ''. + if lx.accept('\'') { + if lx.accept('\'') { + /// Peek ahead: the string can contain ' and '', including at the + /// end: '''str''''' + /// 6 or more at the end, however, is an error. + if lx.peek() == '\'' { + /// Check if we already lexed 5 's; if so we have 6 now, and + /// that's just too many man! + if strings.HasSuffix(lx.current(), "'''''") { + return lx.errorf(`unexpected "''''''"`) + } + lx.backup() + lx.backup() + return lexMultilineRawString + } + + lx.backup() /// backup: don't include the ''' in the item. lx.backup() lx.backup() lx.emit(itemRawMultilineString) - lx.next() + lx.next() /// Read over ''' again and discard it. lx.next() lx.next() lx.ignore() @@ -663,15 +810,14 @@ func lexMultilineRawString(lx *lexer) stateFn { } lx.backup() } + return lexMultilineRawString } - 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()) { + if isNL(lx.next()) { /// \ escaping newline. return lexMultilineString } lx.backup() @@ -694,6 +840,10 @@ func lexStringEscape(lx *lexer) stateFn { fallthrough case '"': fallthrough + case ' ', '\t': + // Inside """ .. """ strings you can use \ to escape newlines, and any + // amount of whitespace can be between the \ and \n. + fallthrough case '\\': return lx.pop() case 'u': @@ -701,9 +851,7 @@ func lexStringEscape(lx *lexer) stateFn { 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) + return lx.error(errLexEscape{r}) } func lexShortUnicodeEscape(lx *lexer) stateFn { @@ -711,8 +859,9 @@ func lexShortUnicodeEscape(lx *lexer) stateFn { for i := 0; i < 4; i++ { r = lx.next() if !isHexadecimal(r) { - return lx.errorf(`expected four hexadecimal digits after '\u', `+ - "but got %q instead", lx.current()) + return lx.errorf( + `expected four hexadecimal digits after '\u', but got %q instead`, + lx.current()) } } return lx.pop() @@ -723,28 +872,33 @@ func lexLongUnicodeEscape(lx *lexer) stateFn { for i := 0; i < 8; i++ { r = lx.next() if !isHexadecimal(r) { - return lx.errorf(`expected eight hexadecimal digits after '\U', `+ - "but got %q instead", lx.current()) + return lx.errorf( + `expected eight hexadecimal digits after '\U', but got %q instead`, + lx.current()) } } return lx.pop() } -// lexNumberOrDateStart consumes either an integer, a float, or datetime. +// lexNumberOrDateStart processes the first character of a value which begins +// with a digit. It exists to catch values starting with '0', so that +// lexBaseNumberOrDate can differentiate base prefixed integers from other +// types. 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 '.'") + case '0': + return lexBaseNumberOrDate } - return lx.errorf("expected a digit but got %q", r) + + if !isDigit(r) { + // The only way to reach this state is if the value starts + // with a digit, so specifically treat anything else as an + // error. + return lx.errorf("expected a digit but got %q", r) + } + + return lexNumberOrDate } // lexNumberOrDate consumes either an integer, float or datetime. @@ -754,10 +908,10 @@ func lexNumberOrDate(lx *lexer) stateFn { return lexNumberOrDate } switch r { - case '-': + case '-', ':': return lexDatetime case '_': - return lexNumber + return lexDecimalNumber case '.', 'e', 'E': return lexFloat } @@ -775,41 +929,156 @@ func lexDatetime(lx *lexer) stateFn { return lexDatetime } switch r { - case '-', 'T', ':', '.', 'Z', '+': + case '-', ':', 'T', 't', ' ', '.', 'Z', 'z', '+': return lexDatetime } lx.backup() - lx.emit(itemDatetime) + lx.emitTrim(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. +// lexHexInteger consumes a hexadecimal integer after seeing the '0x' prefix. +func lexHexInteger(lx *lexer) stateFn { r := lx.next() - if !isDigit(r) { - if r == '.' { - return lx.errorf("floats must start with a digit, not '.'") + if isHexadecimal(r) { + return lexHexInteger + } + switch r { + case '_': + return lexHexInteger + } + + lx.backup() + lx.emit(itemInteger) + return lx.pop() +} + +// lexOctalInteger consumes an octal integer after seeing the '0o' prefix. +func lexOctalInteger(lx *lexer) stateFn { + r := lx.next() + if isOctal(r) { + return lexOctalInteger + } + switch r { + case '_': + return lexOctalInteger + } + + lx.backup() + lx.emit(itemInteger) + return lx.pop() +} + +// lexBinaryInteger consumes a binary integer after seeing the '0b' prefix. +func lexBinaryInteger(lx *lexer) stateFn { + r := lx.next() + if isBinary(r) { + return lexBinaryInteger + } + switch r { + case '_': + return lexBinaryInteger + } + + lx.backup() + lx.emit(itemInteger) + return lx.pop() +} + +// lexDecimalNumber consumes a decimal float or integer. +func lexDecimalNumber(lx *lexer) stateFn { + r := lx.next() + if isDigit(r) { + return lexDecimalNumber + } + switch r { + case '.', 'e', 'E': + return lexFloat + case '_': + return lexDecimalNumber + } + + lx.backup() + lx.emit(itemInteger) + return lx.pop() +} + +// lexDecimalNumber consumes the first digit of a number beginning with a sign. +// It assumes the sign has already been consumed. Values which start with a sign +// are only allowed to be decimal integers or floats. +// +// The special "nan" and "inf" values are also recognized. +func lexDecimalNumberStart(lx *lexer) stateFn { + r := lx.next() + + // Special error cases to give users better error messages + switch r { + case 'i': + if !lx.accept('n') || !lx.accept('f') { + return lx.errorf("invalid float: '%s'", lx.current()) } - return lx.errorf("expected a digit but got %q", r) + lx.emit(itemFloat) + return lx.pop() + case 'n': + if !lx.accept('a') || !lx.accept('n') { + return lx.errorf("invalid float: '%s'", lx.current()) + } + lx.emit(itemFloat) + return lx.pop() + case '0': + p := lx.peek() + switch p { + case 'b', 'o', 'x': + return lx.errorf("cannot use sign with non-decimal numbers: '%s%c'", lx.current(), p) + } + case '.': + return lx.errorf("floats must start with a digit, not '.'") } - return lexNumber + + if isDigit(r) { + return lexDecimalNumber + } + + return lx.errorf("expected a digit but got %q", r) } -// lexNumber consumes an integer or a float after seeing the first digit. -func lexNumber(lx *lexer) stateFn { +// lexBaseNumberOrDate differentiates between the possible values which +// start with '0'. It assumes that before reaching this state, the initial '0' +// has been consumed. +func lexBaseNumberOrDate(lx *lexer) stateFn { r := lx.next() + // Note: All datetimes start with at least two digits, so we don't + // handle date characters (':', '-', etc.) here. if isDigit(r) { - return lexNumber + return lexNumberOrDate } switch r { case '_': - return lexNumber + // Can only be decimal, because there can't be an underscore + // between the '0' and the base designator, and dates can't + // contain underscores. + return lexDecimalNumber case '.', 'e', 'E': return lexFloat + case 'b': + r = lx.peek() + if !isBinary(r) { + lx.errorf("not a binary number: '%s%c'", lx.current(), r) + } + return lexBinaryInteger + case 'o': + r = lx.peek() + if !isOctal(r) { + lx.errorf("not an octal number: '%s%c'", lx.current(), r) + } + return lexOctalInteger + case 'x': + r = lx.peek() + if !isHexadecimal(r) { + lx.errorf("not a hexidecimal number: '%s%c'", lx.current(), r) + } + return lexHexInteger } lx.backup() @@ -867,49 +1136,31 @@ func lexCommentStart(lx *lexer) stateFn { // It will consume *up to* the first newline 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 { + switch r := lx.next(); { + case isNL(r) || r == eof: + lx.backup() lx.emit(itemText) return lx.pop() + default: + return lexComment } - 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') + lx.ignore() + return nextState } -func isBareKeyChar(r rune) bool { - return (r >= 'A' && r <= 'Z') || - (r >= 'a' && r <= 'z') || - (r >= '0' && r <= '9') || - r == '_' || - r == '-' +func (s stateFn) String() string { + name := runtime.FuncForPC(reflect.ValueOf(s).Pointer()).Name() + if i := strings.LastIndexByte(name, '.'); i > -1 { + name = name[i+1:] + } + if s == nil { + name = "<nil>" + } + return name + "()" } func (itype itemType) String() string { @@ -938,12 +1189,18 @@ func (itype itemType) String() string { return "TableEnd" case itemKeyStart: return "KeyStart" + case itemKeyEnd: + return "KeyEnd" case itemArray: return "Array" case itemArrayEnd: return "ArrayEnd" case itemCommentStart: return "CommentStart" + case itemInlineTableStart: + return "InlineTableStart" + case itemInlineTableEnd: + return "InlineTableEnd" } panic(fmt.Sprintf("BUG: Unknown type '%d'.", int(itype))) } @@ -951,3 +1208,26 @@ func (itype itemType) String() string { func (item item) String() string { return fmt.Sprintf("(%s, %s)", item.typ.String(), item.val) } + +func isWhitespace(r rune) bool { return r == '\t' || r == ' ' } +func isNL(r rune) bool { return r == '\n' || r == '\r' } +func isControl(r rune) bool { // Control characters except \t, \r, \n + switch r { + case '\t', '\r', '\n': + return false + default: + return (r >= 0x00 && r <= 0x1f) || r == 0x7f + } +} +func isDigit(r rune) bool { return r >= '0' && r <= '9' } +func isBinary(r rune) bool { return r == '0' || r == '1' } +func isOctal(r rune) bool { return r >= '0' && r <= '7' } +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 == '-' +} |