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/magiconair/properties/lex.go | 409 +++++++++++++++++++++++++ 1 file changed, 409 insertions(+) create mode 100644 vendor/github.com/magiconair/properties/lex.go (limited to 'vendor/github.com/magiconair/properties/lex.go') diff --git a/vendor/github.com/magiconair/properties/lex.go b/vendor/github.com/magiconair/properties/lex.go new file mode 100644 index 0000000..014e63f --- /dev/null +++ b/vendor/github.com/magiconair/properties/lex.go @@ -0,0 +1,409 @@ +// Copyright 2016 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 int(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) { + item := item{t, l.start, string(l.runes)} + l.items <- item + 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.IndexRune(valid, l.next()) >= 0 { + return true + } + l.backup() + return false +} + +// acceptRun consumes a run of runes from the valid set. +func (l *lexer) acceptRun(valid string) { + for strings.IndexRune(valid, l.next()) >= 0 { + } + 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 { + item := <-l.items + l.lastPos = item.pos + return item +} + +// 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.acceptRun(whitespace) + l.ignore() + return lexKey + + 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): + r := l.peek() + if isEOL(r) { + 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) +} -- cgit v1.2.3