// Code generated by pigeon; DO NOT EDIT. package bootcommand import ( "bytes" "errors" "fmt" "io" "io/ioutil" "math" "os" "sort" "strconv" "strings" "sync" "time" "unicode" "unicode/utf8" ) var g = &grammar{ rules: []*rule{ { name: "Input", pos: position{line: 6, col: 1, offset: 26}, expr: &actionExpr{ pos: position{line: 6, col: 10, offset: 35}, run: (*parser).callonInput1, expr: &seqExpr{ pos: position{line: 6, col: 10, offset: 35}, exprs: []interface{}{ &labeledExpr{ pos: position{line: 6, col: 10, offset: 35}, label: "expr", expr: &ruleRefExpr{ pos: position{line: 6, col: 15, offset: 40}, name: "Expr", }, }, &ruleRefExpr{ pos: position{line: 6, col: 20, offset: 45}, name: "EOF", }, }, }, }, }, { name: "Expr", pos: position{line: 10, col: 1, offset: 75}, expr: &actionExpr{ pos: position{line: 10, col: 9, offset: 83}, run: (*parser).callonExpr1, expr: &labeledExpr{ pos: position{line: 10, col: 9, offset: 83}, label: "l", expr: &oneOrMoreExpr{ pos: position{line: 10, col: 11, offset: 85}, expr: &choiceExpr{ pos: position{line: 10, col: 13, offset: 87}, alternatives: []interface{}{ &ruleRefExpr{ pos: position{line: 10, col: 13, offset: 87}, name: "Wait", }, &ruleRefExpr{ pos: position{line: 10, col: 20, offset: 94}, name: "CharToggle", }, &ruleRefExpr{ pos: position{line: 10, col: 33, offset: 107}, name: "Special", }, &ruleRefExpr{ pos: position{line: 10, col: 43, offset: 117}, name: "Literal", }, }, }, }, }, }, }, { name: "Wait", pos: position{line: 14, col: 1, offset: 150}, expr: &actionExpr{ pos: position{line: 14, col: 8, offset: 157}, run: (*parser).callonWait1, expr: &seqExpr{ pos: position{line: 14, col: 8, offset: 157}, exprs: []interface{}{ &ruleRefExpr{ pos: position{line: 14, col: 8, offset: 157}, name: "ExprStart", }, &litMatcher{ pos: position{line: 14, col: 18, offset: 167}, val: "wait", ignoreCase: false, want: "\"wait\"", }, &labeledExpr{ pos: position{line: 14, col: 25, offset: 174}, label: "duration", expr: &zeroOrOneExpr{ pos: position{line: 14, col: 34, offset: 183}, expr: &choiceExpr{ pos: position{line: 14, col: 36, offset: 185}, alternatives: []interface{}{ &ruleRefExpr{ pos: position{line: 14, col: 36, offset: 185}, name: "Duration", }, &ruleRefExpr{ pos: position{line: 14, col: 47, offset: 196}, name: "Integer", }, }, }, }, }, &ruleRefExpr{ pos: position{line: 14, col: 58, offset: 207}, name: "ExprEnd", }, }, }, }, }, { name: "CharToggle", pos: position{line: 27, col: 1, offset: 453}, expr: &actionExpr{ pos: position{line: 27, col: 14, offset: 466}, run: (*parser).callonCharToggle1, expr: &seqExpr{ pos: position{line: 27, col: 14, offset: 466}, exprs: []interface{}{ &ruleRefExpr{ pos: position{line: 27, col: 14, offset: 466}, name: "ExprStart", }, &labeledExpr{ pos: position{line: 27, col: 24, offset: 476}, label: "lit", expr: &ruleRefExpr{ pos: position{line: 27, col: 29, offset: 481}, name: "Literal", }, }, &labeledExpr{ pos: position{line: 27, col: 38, offset: 490}, label: "t", expr: &choiceExpr{ pos: position{line: 27, col: 41, offset: 493}, alternatives: []interface{}{ &ruleRefExpr{ pos: position{line: 27, col: 41, offset: 493}, name: "On", }, &ruleRefExpr{ pos: position{line: 27, col: 46, offset: 498}, name: "Off", }, }, }, }, &ruleRefExpr{ pos: position{line: 27, col: 51, offset: 503}, name: "ExprEnd", }, }, }, }, }, { name: "Special", pos: position{line: 31, col: 1, offset: 574}, expr: &actionExpr{ pos: position{line: 31, col: 11, offset: 584}, run: (*parser).callonSpecial1, expr: &seqExpr{ pos: position{line: 31, col: 11, offset: 584}, exprs: []interface{}{ &ruleRefExpr{ pos: position{line: 31, col: 11, offset: 584}, name: "ExprStart", }, &labeledExpr{ pos: position{line: 31, col: 21, offset: 594}, label: "s", expr: &ruleRefExpr{ pos: position{line: 31, col: 24, offset: 597}, name: "SpecialKey", }, }, &labeledExpr{ pos: position{line: 31, col: 36, offset: 609}, label: "t", expr: &zeroOrOneExpr{ pos: position{line: 31, col: 38, offset: 611}, expr: &choiceExpr{ pos: position{line: 31, col: 39, offset: 612}, alternatives: []interface{}{ &ruleRefExpr{ pos: position{line: 31, col: 39, offset: 612}, name: "On", }, &ruleRefExpr{ pos: position{line: 31, col: 44, offset: 617}, name: "Off", }, }, }, }, }, &ruleRefExpr{ pos: position{line: 31, col: 50, offset: 623}, name: "ExprEnd", }, }, }, }, }, { name: "Number", pos: position{line: 39, col: 1, offset: 810}, expr: &actionExpr{ pos: position{line: 39, col: 10, offset: 819}, run: (*parser).callonNumber1, expr: &seqExpr{ pos: position{line: 39, col: 10, offset: 819}, exprs: []interface{}{ &zeroOrOneExpr{ pos: position{line: 39, col: 10, offset: 819}, expr: &litMatcher{ pos: position{line: 39, col: 10, offset: 819}, val: "-", ignoreCase: false, want: "\"-\"", }, }, &ruleRefExpr{ pos: position{line: 39, col: 15, offset: 824}, name: "Integer", }, &zeroOrOneExpr{ pos: position{line: 39, col: 23, offset: 832}, expr: &seqExpr{ pos: position{line: 39, col: 25, offset: 834}, exprs: []interface{}{ &litMatcher{ pos: position{line: 39, col: 25, offset: 834}, val: ".", ignoreCase: false, want: "\".\"", }, &oneOrMoreExpr{ pos: position{line: 39, col: 29, offset: 838}, expr: &ruleRefExpr{ pos: position{line: 39, col: 29, offset: 838}, name: "Digit", }, }, }, }, }, }, }, }, }, { name: "Integer", pos: position{line: 43, col: 1, offset: 884}, expr: &choiceExpr{ pos: position{line: 43, col: 11, offset: 894}, alternatives: []interface{}{ &litMatcher{ pos: position{line: 43, col: 11, offset: 894}, val: "0", ignoreCase: false, want: "\"0\"", }, &actionExpr{ pos: position{line: 43, col: 17, offset: 900}, run: (*parser).callonInteger3, expr: &seqExpr{ pos: position{line: 43, col: 17, offset: 900}, exprs: []interface{}{ &ruleRefExpr{ pos: position{line: 43, col: 17, offset: 900}, name: "NonZeroDigit", }, &zeroOrMoreExpr{ pos: position{line: 43, col: 30, offset: 913}, expr: &ruleRefExpr{ pos: position{line: 43, col: 30, offset: 913}, name: "Digit", }, }, }, }, }, }, }, }, { name: "Duration", pos: position{line: 47, col: 1, offset: 977}, expr: &actionExpr{ pos: position{line: 47, col: 12, offset: 988}, run: (*parser).callonDuration1, expr: &oneOrMoreExpr{ pos: position{line: 47, col: 12, offset: 988}, expr: &seqExpr{ pos: position{line: 47, col: 14, offset: 990}, exprs: []interface{}{ &ruleRefExpr{ pos: position{line: 47, col: 14, offset: 990}, name: "Number", }, &ruleRefExpr{ pos: position{line: 47, col: 21, offset: 997}, name: "TimeUnit", }, }, }, }, }, }, { name: "On", pos: position{line: 51, col: 1, offset: 1060}, expr: &actionExpr{ pos: position{line: 51, col: 6, offset: 1065}, run: (*parser).callonOn1, expr: &litMatcher{ pos: position{line: 51, col: 6, offset: 1065}, val: "on", ignoreCase: true, want: "\"on\"i", }, }, }, { name: "Off", pos: position{line: 55, col: 1, offset: 1098}, expr: &actionExpr{ pos: position{line: 55, col: 7, offset: 1104}, run: (*parser).callonOff1, expr: &litMatcher{ pos: position{line: 55, col: 7, offset: 1104}, val: "off", ignoreCase: true, want: "\"off\"i", }, }, }, { name: "Literal", pos: position{line: 59, col: 1, offset: 1139}, expr: &actionExpr{ pos: position{line: 59, col: 11, offset: 1149}, run: (*parser).callonLiteral1, expr: &anyMatcher{ line: 59, col: 11, offset: 1149, }, }, }, { name: "ExprEnd", pos: position{line: 64, col: 1, offset: 1230}, expr: &litMatcher{ pos: position{line: 64, col: 11, offset: 1240}, val: ">", ignoreCase: false, want: "\">\"", }, }, { name: "ExprStart", pos: position{line: 65, col: 1, offset: 1244}, expr: &litMatcher{ pos: position{line: 65, col: 13, offset: 1256}, val: "<", ignoreCase: false, want: "\"<\"", }, }, { name: "SpecialKey", pos: position{line: 66, col: 1, offset: 1260}, expr: &choiceExpr{ pos: position{line: 66, col: 14, offset: 1273}, alternatives: []interface{}{ &litMatcher{ pos: position{line: 66, col: 14, offset: 1273}, val: "bs", ignoreCase: true, want: "\"bs\"i", }, &litMatcher{ pos: position{line: 66, col: 22, offset: 1281}, val: "del", ignoreCase: true, want: "\"del\"i", }, &litMatcher{ pos: position{line: 66, col: 31, offset: 1290}, val: "enter", ignoreCase: true, want: "\"enter\"i", }, &litMatcher{ pos: position{line: 66, col: 42, offset: 1301}, val: "esc", ignoreCase: true, want: "\"esc\"i", }, &litMatcher{ pos: position{line: 66, col: 51, offset: 1310}, val: "f10", ignoreCase: true, want: "\"f10\"i", }, &litMatcher{ pos: position{line: 66, col: 60, offset: 1319}, val: "f11", ignoreCase: true, want: "\"f11\"i", }, &litMatcher{ pos: position{line: 66, col: 69, offset: 1328}, val: "f12", ignoreCase: true, want: "\"f12\"i", }, &litMatcher{ pos: position{line: 67, col: 11, offset: 1345}, val: "f1", ignoreCase: true, want: "\"f1\"i", }, &litMatcher{ pos: position{line: 67, col: 19, offset: 1353}, val: "f2", ignoreCase: true, want: "\"f2\"i", }, &litMatcher{ pos: position{line: 67, col: 27, offset: 1361}, val: "f3", ignoreCase: true, want: "\"f3\"i", }, &litMatcher{ pos: position{line: 67, col: 35, offset: 1369}, val: "f4", ignoreCase: true, want: "\"f4\"i", }, &litMatcher{ pos: position{line: 67, col: 43, offset: 1377}, val: "f5", ignoreCase: true, want: "\"f5\"i", }, &litMatcher{ pos: position{line: 67, col: 51, offset: 1385}, val: "f6", ignoreCase: true, want: "\"f6\"i", }, &litMatcher{ pos: position{line: 67, col: 59, offset: 1393}, val: "f7", ignoreCase: true, want: "\"f7\"i", }, &litMatcher{ pos: position{line: 67, col: 67, offset: 1401}, val: "f8", ignoreCase: true, want: "\"f8\"i", }, &litMatcher{ pos: position{line: 67, col: 75, offset: 1409}, val: "f9", ignoreCase: true, want: "\"f9\"i", }, &litMatcher{ pos: position{line: 68, col: 12, offset: 1426}, val: "return", ignoreCase: true, want: "\"return\"i", }, &litMatcher{ pos: position{line: 68, col: 24, offset: 1438}, val: "tab", ignoreCase: true, want: "\"tab\"i", }, &litMatcher{ pos: position{line: 68, col: 33, offset: 1447}, val: "up", ignoreCase: true, want: "\"up\"i", }, &litMatcher{ pos: position{line: 68, col: 41, offset: 1455}, val: "down", ignoreCase: true, want: "\"down\"i", }, &litMatcher{ pos: position{line: 68, col: 51, offset: 1465}, val: "spacebar", ignoreCase: true, want: "\"spacebar\"i", }, &litMatcher{ pos: position{line: 68, col: 65, offset: 1479}, val: "insert", ignoreCase: true, want: "\"insert\"i", }, &litMatcher{ pos: position{line: 68, col: 77, offset: 1491}, val: "home", ignoreCase: true, want: "\"home\"i", }, &litMatcher{ pos: position{line: 69, col: 11, offset: 1509}, val: "end", ignoreCase: true, want: "\"end\"i", }, &litMatcher{ pos: position{line: 69, col: 20, offset: 1518}, val: "pageup", ignoreCase: true, want: "\"pageUp\"i", }, &litMatcher{ pos: position{line: 69, col: 32, offset: 1530}, val: "pagedown", ignoreCase: true, want: "\"pageDown\"i", }, &litMatcher{ pos: position{line: 69, col: 46, offset: 1544}, val: "leftalt", ignoreCase: true, want: "\"leftAlt\"i", }, &litMatcher{ pos: position{line: 69, col: 59, offset: 1557}, val: "leftctrl", ignoreCase: true, want: "\"leftCtrl\"i", }, &litMatcher{ pos: position{line: 69, col: 73, offset: 1571}, val: "leftshift", ignoreCase: true, want: "\"leftShift\"i", }, &litMatcher{ pos: position{line: 70, col: 11, offset: 1594}, val: "rightalt", ignoreCase: true, want: "\"rightAlt\"i", }, &litMatcher{ pos: position{line: 70, col: 25, offset: 1608}, val: "rightctrl", ignoreCase: true, want: "\"rightCtrl\"i", }, &litMatcher{ pos: position{line: 70, col: 40, offset: 1623}, val: "rightshift", ignoreCase: true, want: "\"rightShift\"i", }, &litMatcher{ pos: position{line: 70, col: 56, offset: 1639}, val: "leftsuper", ignoreCase: true, want: "\"leftSuper\"i", }, &litMatcher{ pos: position{line: 70, col: 71, offset: 1654}, val: "rightsuper", ignoreCase: true, want: "\"rightSuper\"i", }, &litMatcher{ pos: position{line: 71, col: 11, offset: 1678}, val: "left", ignoreCase: true, want: "\"left\"i", }, &litMatcher{ pos: position{line: 71, col: 21, offset: 1688}, val: "right", ignoreCase: true, want: "\"right\"i", }, }, }, }, { name: "NonZeroDigit", pos: position{line: 73, col: 1, offset: 1698}, expr: &charClassMatcher{ pos: position{line: 73, col: 16, offset: 1713}, val: "[1-9]", ranges: []rune{'1', '9'}, ignoreCase: false, inverted: false, }, }, { name: "Digit", pos: position{line: 74, col: 1, offset: 1719}, expr: &charClassMatcher{ pos: position{line: 74, col: 9, offset: 1727}, val: "[0-9]", ranges: []rune{'0', '9'}, ignoreCase: false, inverted: false, }, }, { name: "TimeUnit", pos: position{line: 75, col: 1, offset: 1733}, expr: &choiceExpr{ pos: position{line: 75, col: 13, offset: 1745}, alternatives: []interface{}{ &litMatcher{ pos: position{line: 75, col: 13, offset: 1745}, val: "ns", ignoreCase: false, want: "\"ns\"", }, &litMatcher{ pos: position{line: 75, col: 20, offset: 1752}, val: "us", ignoreCase: false, want: "\"us\"", }, &litMatcher{ pos: position{line: 75, col: 27, offset: 1759}, val: "µs", ignoreCase: false, want: "\"µs\"", }, &litMatcher{ pos: position{line: 75, col: 34, offset: 1767}, val: "ms", ignoreCase: false, want: "\"ms\"", }, &litMatcher{ pos: position{line: 75, col: 41, offset: 1774}, val: "s", ignoreCase: false, want: "\"s\"", }, &litMatcher{ pos: position{line: 75, col: 47, offset: 1780}, val: "m", ignoreCase: false, want: "\"m\"", }, &litMatcher{ pos: position{line: 75, col: 53, offset: 1786}, val: "h", ignoreCase: false, want: "\"h\"", }, }, }, }, { name: "_", displayName: "\"whitespace\"", pos: position{line: 77, col: 1, offset: 1792}, expr: &zeroOrMoreExpr{ pos: position{line: 77, col: 19, offset: 1810}, expr: &charClassMatcher{ pos: position{line: 77, col: 19, offset: 1810}, val: "[ \\n\\t\\r]", chars: []rune{' ', '\n', '\t', '\r'}, ignoreCase: false, inverted: false, }, }, }, { name: "EOF", pos: position{line: 79, col: 1, offset: 1822}, expr: ¬Expr{ pos: position{line: 79, col: 8, offset: 1829}, expr: &anyMatcher{ line: 79, col: 9, offset: 1830, }, }, }, }, } func (c *current) onInput1(expr interface{}) (interface{}, error) { return expr, nil } func (p *parser) callonInput1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onInput1(stack["expr"]) } func (c *current) onExpr1(l interface{}) (interface{}, error) { return l, nil } func (p *parser) callonExpr1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onExpr1(stack["l"]) } func (c *current) onWait1(duration interface{}) (interface{}, error) { var d time.Duration switch t := duration.(type) { case time.Duration: d = t case int64: d = time.Duration(t) * time.Second default: d = time.Second } return &waitExpression{d}, nil } func (p *parser) callonWait1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onWait1(stack["duration"]) } func (c *current) onCharToggle1(lit, t interface{}) (interface{}, error) { return &literal{lit.(*literal).s, t.(KeyAction)}, nil } func (p *parser) callonCharToggle1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onCharToggle1(stack["lit"], stack["t"]) } func (c *current) onSpecial1(s, t interface{}) (interface{}, error) { l := strings.ToLower(string(s.([]byte))) if t == nil { return &specialExpression{l, KeyPress}, nil } return &specialExpression{l, t.(KeyAction)}, nil } func (p *parser) callonSpecial1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onSpecial1(stack["s"], stack["t"]) } func (c *current) onNumber1() (interface{}, error) { return string(c.text), nil } func (p *parser) callonNumber1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onNumber1() } func (c *current) onInteger3() (interface{}, error) { return strconv.ParseInt(string(c.text), 10, 64) } func (p *parser) callonInteger3() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onInteger3() } func (c *current) onDuration1() (interface{}, error) { return time.ParseDuration(string(c.text)) } func (p *parser) callonDuration1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onDuration1() } func (c *current) onOn1() (interface{}, error) { return KeyOn, nil } func (p *parser) callonOn1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onOn1() } func (c *current) onOff1() (interface{}, error) { return KeyOff, nil } func (p *parser) callonOff1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onOff1() } func (c *current) onLiteral1() (interface{}, error) { r, _ := utf8.DecodeRune(c.text) return &literal{r, KeyPress}, nil } func (p *parser) callonLiteral1() (interface{}, error) { stack := p.vstack[len(p.vstack)-1] _ = stack return p.cur.onLiteral1() } var ( // errNoRule is returned when the grammar to parse has no rule. errNoRule = errors.New("grammar has no rule") // errInvalidEntrypoint is returned when the specified entrypoint rule // does not exit. errInvalidEntrypoint = errors.New("invalid entrypoint") // errInvalidEncoding is returned when the source is not properly // utf8-encoded. errInvalidEncoding = errors.New("invalid encoding") // errMaxExprCnt is used to signal that the maximum number of // expressions have been parsed. errMaxExprCnt = errors.New("max number of expresssions parsed") ) // Option is a function that can set an option on the parser. It returns // the previous setting as an Option. type Option func(*parser) Option // MaxExpressions creates an Option to stop parsing after the provided // number of expressions have been parsed, if the value is 0 then the parser will // parse for as many steps as needed (possibly an infinite number). // // The default for maxExprCnt is 0. func MaxExpressions(maxExprCnt uint64) Option { return func(p *parser) Option { oldMaxExprCnt := p.maxExprCnt p.maxExprCnt = maxExprCnt return MaxExpressions(oldMaxExprCnt) } } // Entrypoint creates an Option to set the rule name to use as entrypoint. // The rule name must have been specified in the -alternate-entrypoints // if generating the parser with the -optimize-grammar flag, otherwise // it may have been optimized out. Passing an empty string sets the // entrypoint to the first rule in the grammar. // // The default is to start parsing at the first rule in the grammar. func Entrypoint(ruleName string) Option { return func(p *parser) Option { oldEntrypoint := p.entrypoint p.entrypoint = ruleName if ruleName == "" { p.entrypoint = g.rules[0].name } return Entrypoint(oldEntrypoint) } } // Statistics adds a user provided Stats struct to the parser to allow // the user to process the results after the parsing has finished. // Also the key for the "no match" counter is set. // // Example usage: // // input := "input" // stats := Stats{} // _, err := Parse("input-file", []byte(input), Statistics(&stats, "no match")) // if err != nil { // log.Panicln(err) // } // b, err := json.MarshalIndent(stats.ChoiceAltCnt, "", " ") // if err != nil { // log.Panicln(err) // } // fmt.Println(string(b)) // func Statistics(stats *Stats, choiceNoMatch string) Option { return func(p *parser) Option { oldStats := p.Stats p.Stats = stats oldChoiceNoMatch := p.choiceNoMatch p.choiceNoMatch = choiceNoMatch if p.Stats.ChoiceAltCnt == nil { p.Stats.ChoiceAltCnt = make(map[string]map[string]int) } return Statistics(oldStats, oldChoiceNoMatch) } } // Debug creates an Option to set the debug flag to b. When set to true, // debugging information is printed to stdout while parsing. // // The default is false. func Debug(b bool) Option { return func(p *parser) Option { old := p.debug p.debug = b return Debug(old) } } // Memoize creates an Option to set the memoize flag to b. When set to true, // the parser will cache all results so each expression is evaluated only // once. This guarantees linear parsing time even for pathological cases, // at the expense of more memory and slower times for typical cases. // // The default is false. func Memoize(b bool) Option { return func(p *parser) Option { old := p.memoize p.memoize = b return Memoize(old) } } // AllowInvalidUTF8 creates an Option to allow invalid UTF-8 bytes. // Every invalid UTF-8 byte is treated as a utf8.RuneError (U+FFFD) // by character class matchers and is matched by the any matcher. // The returned matched value, c.text and c.offset are NOT affected. // // The default is false. func AllowInvalidUTF8(b bool) Option { return func(p *parser) Option { old := p.allowInvalidUTF8 p.allowInvalidUTF8 = b return AllowInvalidUTF8(old) } } // Recover creates an Option to set the recover flag to b. When set to // true, this causes the parser to recover from panics and convert it // to an error. Setting it to false can be useful while debugging to // access the full stack trace. // // The default is true. func Recover(b bool) Option { return func(p *parser) Option { old := p.recover p.recover = b return Recover(old) } } // GlobalStore creates an Option to set a key to a certain value in // the globalStore. func GlobalStore(key string, value interface{}) Option { return func(p *parser) Option { old := p.cur.globalStore[key] p.cur.globalStore[key] = value return GlobalStore(key, old) } } // InitState creates an Option to set a key to a certain value in // the global "state" store. func InitState(key string, value interface{}) Option { return func(p *parser) Option { old := p.cur.state[key] p.cur.state[key] = value return InitState(key, old) } } // ParseFile parses the file identified by filename. func ParseFile(filename string, opts ...Option) (i interface{}, err error) { f, err := os.Open(filename) if err != nil { return nil, err } defer func() { if closeErr := f.Close(); closeErr != nil { err = closeErr } }() return ParseReader(filename, f, opts...) } // ParseReader parses the data from r using filename as information in the // error messages. func ParseReader(filename string, r io.Reader, opts ...Option) (interface{}, error) { b, err := ioutil.ReadAll(r) if err != nil { return nil, err } return Parse(filename, b, opts...) } // Parse parses the data from b using filename as information in the // error messages. func Parse(filename string, b []byte, opts ...Option) (interface{}, error) { return newParser(filename, b, opts...).parse(g) } // position records a position in the text. type position struct { line, col, offset int } func (p position) String() string { return strconv.Itoa(p.line) + ":" + strconv.Itoa(p.col) + " [" + strconv.Itoa(p.offset) + "]" } // savepoint stores all state required to go back to this point in the // parser. type savepoint struct { position rn rune w int } type current struct { pos position // start position of the match text []byte // raw text of the match // state is a store for arbitrary key,value pairs that the user wants to be // tied to the backtracking of the parser. // This is always rolled back if a parsing rule fails. state storeDict // globalStore is a general store for the user to store arbitrary key-value // pairs that they need to manage and that they do not want tied to the // backtracking of the parser. This is only modified by the user and never // rolled back by the parser. It is always up to the user to keep this in a // consistent state. globalStore storeDict } type storeDict map[string]interface{} // the AST types... type grammar struct { pos position rules []*rule } type rule struct { pos position name string displayName string expr interface{} } type choiceExpr struct { pos position alternatives []interface{} } type actionExpr struct { pos position expr interface{} run func(*parser) (interface{}, error) } type recoveryExpr struct { pos position expr interface{} recoverExpr interface{} failureLabel []string } type seqExpr struct { pos position exprs []interface{} } type throwExpr struct { pos position label string } type labeledExpr struct { pos position label string expr interface{} } type expr struct { pos position expr interface{} } type andExpr expr type notExpr expr type zeroOrOneExpr expr type zeroOrMoreExpr expr type oneOrMoreExpr expr type ruleRefExpr struct { pos position name string } type stateCodeExpr struct { pos position run func(*parser) error } type andCodeExpr struct { pos position run func(*parser) (bool, error) } type notCodeExpr struct { pos position run func(*parser) (bool, error) } type litMatcher struct { pos position val string ignoreCase bool want string } type charClassMatcher struct { pos position val string basicLatinChars [128]bool chars []rune ranges []rune classes []*unicode.RangeTable ignoreCase bool inverted bool } type anyMatcher position // errList cumulates the errors found by the parser. type errList []error func (e *errList) add(err error) { *e = append(*e, err) } func (e errList) err() error { if len(e) == 0 { return nil } e.dedupe() return e } func (e *errList) dedupe() { var cleaned []error set := make(map[string]bool) for _, err := range *e { if msg := err.Error(); !set[msg] { set[msg] = true cleaned = append(cleaned, err) } } *e = cleaned } func (e errList) Error() string { switch len(e) { case 0: return "" case 1: return e[0].Error() default: var buf bytes.Buffer for i, err := range e { if i > 0 { buf.WriteRune('\n') } buf.WriteString(err.Error()) } return buf.String() } } // parserError wraps an error with a prefix indicating the rule in which // the error occurred. The original error is stored in the Inner field. type parserError struct { Inner error pos position prefix string expected []string } // Error returns the error message. func (p *parserError) Error() string { return p.prefix + ": " + p.Inner.Error() } // newParser creates a parser with the specified input source and options. func newParser(filename string, b []byte, opts ...Option) *parser { stats := Stats{ ChoiceAltCnt: make(map[string]map[string]int), } p := &parser{ filename: filename, errs: new(errList), data: b, pt: savepoint{position: position{line: 1}}, recover: true, cur: current{ state: make(storeDict), globalStore: make(storeDict), }, maxFailPos: position{col: 1, line: 1}, maxFailExpected: make([]string, 0, 20), Stats: &stats, // start rule is rule [0] unless an alternate entrypoint is specified entrypoint: g.rules[0].name, } p.setOptions(opts) if p.maxExprCnt == 0 { p.maxExprCnt = math.MaxUint64 } return p } // setOptions applies the options to the parser. func (p *parser) setOptions(opts []Option) { for _, opt := range opts { opt(p) } } type resultTuple struct { v interface{} b bool end savepoint } const choiceNoMatch = -1 // Stats stores some statistics, gathered during parsing type Stats struct { // ExprCnt counts the number of expressions processed during parsing // This value is compared to the maximum number of expressions allowed // (set by the MaxExpressions option). ExprCnt uint64 // ChoiceAltCnt is used to count for each ordered choice expression, // which alternative is used how may times. // These numbers allow to optimize the order of the ordered choice expression // to increase the performance of the parser // // The outer key of ChoiceAltCnt is composed of the name of the rule as well // as the line and the column of the ordered choice. // The inner key of ChoiceAltCnt is the number (one-based) of the matching alternative. // For each alternative the number of matches are counted. If an ordered choice does not // match, a special counter is incremented. The name of this counter is set with // the parser option Statistics. // For an alternative to be included in ChoiceAltCnt, it has to match at least once. ChoiceAltCnt map[string]map[string]int } type parser struct { filename string pt savepoint cur current data []byte errs *errList depth int recover bool debug bool memoize bool // memoization table for the packrat algorithm: // map[offset in source] map[expression or rule] {value, match} memo map[int]map[interface{}]resultTuple // rules table, maps the rule identifier to the rule node rules map[string]*rule // variables stack, map of label to value vstack []map[string]interface{} // rule stack, allows identification of the current rule in errors rstack []*rule // parse fail maxFailPos position maxFailExpected []string maxFailInvertExpected bool // max number of expressions to be parsed maxExprCnt uint64 // entrypoint for the parser entrypoint string allowInvalidUTF8 bool *Stats choiceNoMatch string // recovery expression stack, keeps track of the currently available recovery expression, these are traversed in reverse recoveryStack []map[string]interface{} } // push a variable set on the vstack. func (p *parser) pushV() { if cap(p.vstack) == len(p.vstack) { // create new empty slot in the stack p.vstack = append(p.vstack, nil) } else { // slice to 1 more p.vstack = p.vstack[:len(p.vstack)+1] } // get the last args set m := p.vstack[len(p.vstack)-1] if m != nil && len(m) == 0 { // empty map, all good return } m = make(map[string]interface{}) p.vstack[len(p.vstack)-1] = m } // pop a variable set from the vstack. func (p *parser) popV() { // if the map is not empty, clear it m := p.vstack[len(p.vstack)-1] if len(m) > 0 { // GC that map p.vstack[len(p.vstack)-1] = nil } p.vstack = p.vstack[:len(p.vstack)-1] } // push a recovery expression with its labels to the recoveryStack func (p *parser) pushRecovery(labels []string, expr interface{}) { if cap(p.recoveryStack) == len(p.recoveryStack) { // create new empty slot in the stack p.recoveryStack = append(p.recoveryStack, nil) } else { // slice to 1 more p.recoveryStack = p.recoveryStack[:len(p.recoveryStack)+1] } m := make(map[string]interface{}, len(labels)) for _, fl := range labels { m[fl] = expr } p.recoveryStack[len(p.recoveryStack)-1] = m } // pop a recovery expression from the recoveryStack func (p *parser) popRecovery() { // GC that map p.recoveryStack[len(p.recoveryStack)-1] = nil p.recoveryStack = p.recoveryStack[:len(p.recoveryStack)-1] } func (p *parser) print(prefix, s string) string { if !p.debug { return s } fmt.Printf("%s %d:%d:%d: %s [%#U]\n", prefix, p.pt.line, p.pt.col, p.pt.offset, s, p.pt.rn) return s } func (p *parser) in(s string) string { p.depth++ return p.print(strings.Repeat(" ", p.depth)+">", s) } func (p *parser) out(s string) string { p.depth-- return p.print(strings.Repeat(" ", p.depth)+"<", s) } func (p *parser) addErr(err error) { p.addErrAt(err, p.pt.position, []string{}) } func (p *parser) addErrAt(err error, pos position, expected []string) { var buf bytes.Buffer if p.filename != "" { buf.WriteString(p.filename) } if buf.Len() > 0 { buf.WriteString(":") } buf.WriteString(fmt.Sprintf("%d:%d (%d)", pos.line, pos.col, pos.offset)) if len(p.rstack) > 0 { if buf.Len() > 0 { buf.WriteString(": ") } rule := p.rstack[len(p.rstack)-1] if rule.displayName != "" { buf.WriteString("rule " + rule.displayName) } else { buf.WriteString("rule " + rule.name) } } pe := &parserError{Inner: err, pos: pos, prefix: buf.String(), expected: expected} p.errs.add(pe) } func (p *parser) failAt(fail bool, pos position, want string) { // process fail if parsing fails and not inverted or parsing succeeds and invert is set if fail == p.maxFailInvertExpected { if pos.offset < p.maxFailPos.offset { return } if pos.offset > p.maxFailPos.offset { p.maxFailPos = pos p.maxFailExpected = p.maxFailExpected[:0] } if p.maxFailInvertExpected { want = "!" + want } p.maxFailExpected = append(p.maxFailExpected, want) } } // read advances the parser to the next rune. func (p *parser) read() { p.pt.offset += p.pt.w rn, n := utf8.DecodeRune(p.data[p.pt.offset:]) p.pt.rn = rn p.pt.w = n p.pt.col++ if rn == '\n' { p.pt.line++ p.pt.col = 0 } if rn == utf8.RuneError && n == 1 { // see utf8.DecodeRune if !p.allowInvalidUTF8 { p.addErr(errInvalidEncoding) } } } // restore parser position to the savepoint pt. func (p *parser) restore(pt savepoint) { if p.debug { defer p.out(p.in("restore")) } if pt.offset == p.pt.offset { return } p.pt = pt } // Cloner is implemented by any value that has a Clone method, which returns a // copy of the value. This is mainly used for types which are not passed by // value (e.g map, slice, chan) or structs that contain such types. // // This is used in conjunction with the global state feature to create proper // copies of the state to allow the parser to properly restore the state in // the case of backtracking. type Cloner interface { Clone() interface{} } var statePool = &sync.Pool{ New: func() interface{} { return make(storeDict) }, } func (sd storeDict) Discard() { for k := range sd { delete(sd, k) } statePool.Put(sd) } // clone and return parser current state. func (p *parser) cloneState() storeDict { if p.debug { defer p.out(p.in("cloneState")) } state := statePool.Get().(storeDict) for k, v := range p.cur.state { if c, ok := v.(Cloner); ok { state[k] = c.Clone() } else { state[k] = v } } return state } // restore parser current state to the state storeDict. // every restoreState should applied only one time for every cloned state func (p *parser) restoreState(state storeDict) { if p.debug { defer p.out(p.in("restoreState")) } p.cur.state.Discard() p.cur.state = state } // get the slice of bytes from the savepoint start to the current position. func (p *parser) sliceFrom(start savepoint) []byte { return p.data[start.position.offset:p.pt.position.offset] } func (p *parser) getMemoized(node interface{}) (resultTuple, bool) { if len(p.memo) == 0 { return resultTuple{}, false } m := p.memo[p.pt.offset] if len(m) == 0 { return resultTuple{}, false } res, ok := m[node] return res, ok } func (p *parser) setMemoized(pt savepoint, node interface{}, tuple resultTuple) { if p.memo == nil { p.memo = make(map[int]map[interface{}]resultTuple) } m := p.memo[pt.offset] if m == nil { m = make(map[interface{}]resultTuple) p.memo[pt.offset] = m } m[node] = tuple } func (p *parser) buildRulesTable(g *grammar) { p.rules = make(map[string]*rule, len(g.rules)) for _, r := range g.rules { p.rules[r.name] = r } } func (p *parser) parse(g *grammar) (val interface{}, err error) { if len(g.rules) == 0 { p.addErr(errNoRule) return nil, p.errs.err() } // TODO : not super critical but this could be generated p.buildRulesTable(g) if p.recover { // panic can be used in action code to stop parsing immediately // and return the panic as an error. defer func() { if e := recover(); e != nil { if p.debug { defer p.out(p.in("panic handler")) } val = nil switch e := e.(type) { case error: p.addErr(e) default: p.addErr(fmt.Errorf("%v", e)) } err = p.errs.err() } }() } startRule, ok := p.rules[p.entrypoint] if !ok { p.addErr(errInvalidEntrypoint) return nil, p.errs.err() } p.read() // advance to first rune val, ok = p.parseRule(startRule) if !ok { if len(*p.errs) == 0 { // If parsing fails, but no errors have been recorded, the expected values // for the farthest parser position are returned as error. maxFailExpectedMap := make(map[string]struct{}, len(p.maxFailExpected)) for _, v := range p.maxFailExpected { maxFailExpectedMap[v] = struct{}{} } expected := make([]string, 0, len(maxFailExpectedMap)) eof := false if _, ok := maxFailExpectedMap["!."]; ok { delete(maxFailExpectedMap, "!.") eof = true } for k := range maxFailExpectedMap { expected = append(expected, k) } sort.Strings(expected) if eof { expected = append(expected, "EOF") } p.addErrAt(errors.New("no match found, expected: "+listJoin(expected, ", ", "or")), p.maxFailPos, expected) } return nil, p.errs.err() } return val, p.errs.err() } func listJoin(list []string, sep string, lastSep string) string { switch len(list) { case 0: return "" case 1: return list[0] default: return strings.Join(list[:len(list)-1], sep) + " " + lastSep + " " + list[len(list)-1] } } func (p *parser) parseRule(rule *rule) (interface{}, bool) { if p.debug { defer p.out(p.in("parseRule " + rule.name)) } if p.memoize { res, ok := p.getMemoized(rule) if ok { p.restore(res.end) return res.v, res.b } } start := p.pt p.rstack = append(p.rstack, rule) p.pushV() val, ok := p.parseExpr(rule.expr) p.popV() p.rstack = p.rstack[:len(p.rstack)-1] if ok && p.debug { p.print(strings.Repeat(" ", p.depth)+"MATCH", string(p.sliceFrom(start))) } if p.memoize { p.setMemoized(start, rule, resultTuple{val, ok, p.pt}) } return val, ok } func (p *parser) parseExpr(expr interface{}) (interface{}, bool) { var pt savepoint if p.memoize { res, ok := p.getMemoized(expr) if ok { p.restore(res.end) return res.v, res.b } pt = p.pt } p.ExprCnt++ if p.ExprCnt > p.maxExprCnt { panic(errMaxExprCnt) } var val interface{} var ok bool switch expr := expr.(type) { case *actionExpr: val, ok = p.parseActionExpr(expr) case *andCodeExpr: val, ok = p.parseAndCodeExpr(expr) case *andExpr: val, ok = p.parseAndExpr(expr) case *anyMatcher: val, ok = p.parseAnyMatcher(expr) case *charClassMatcher: val, ok = p.parseCharClassMatcher(expr) case *choiceExpr: val, ok = p.parseChoiceExpr(expr) case *labeledExpr: val, ok = p.parseLabeledExpr(expr) case *litMatcher: val, ok = p.parseLitMatcher(expr) case *notCodeExpr: val, ok = p.parseNotCodeExpr(expr) case *notExpr: val, ok = p.parseNotExpr(expr) case *oneOrMoreExpr: val, ok = p.parseOneOrMoreExpr(expr) case *recoveryExpr: val, ok = p.parseRecoveryExpr(expr) case *ruleRefExpr: val, ok = p.parseRuleRefExpr(expr) case *seqExpr: val, ok = p.parseSeqExpr(expr) case *stateCodeExpr: val, ok = p.parseStateCodeExpr(expr) case *throwExpr: val, ok = p.parseThrowExpr(expr) case *zeroOrMoreExpr: val, ok = p.parseZeroOrMoreExpr(expr) case *zeroOrOneExpr: val, ok = p.parseZeroOrOneExpr(expr) default: panic(fmt.Sprintf("unknown expression type %T", expr)) } if p.memoize { p.setMemoized(pt, expr, resultTuple{val, ok, p.pt}) } return val, ok } func (p *parser) parseActionExpr(act *actionExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseActionExpr")) } start := p.pt val, ok := p.parseExpr(act.expr) if ok { p.cur.pos = start.position p.cur.text = p.sliceFrom(start) state := p.cloneState() actVal, err := act.run(p) if err != nil { p.addErrAt(err, start.position, []string{}) } p.restoreState(state) val = actVal } if ok && p.debug { p.print(strings.Repeat(" ", p.depth)+"MATCH", string(p.sliceFrom(start))) } return val, ok } func (p *parser) parseAndCodeExpr(and *andCodeExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseAndCodeExpr")) } state := p.cloneState() ok, err := and.run(p) if err != nil { p.addErr(err) } p.restoreState(state) return nil, ok } func (p *parser) parseAndExpr(and *andExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseAndExpr")) } pt := p.pt state := p.cloneState() p.pushV() _, ok := p.parseExpr(and.expr) p.popV() p.restoreState(state) p.restore(pt) return nil, ok } func (p *parser) parseAnyMatcher(any *anyMatcher) (interface{}, bool) { if p.debug { defer p.out(p.in("parseAnyMatcher")) } if p.pt.rn == utf8.RuneError && p.pt.w == 0 { // EOF - see utf8.DecodeRune p.failAt(false, p.pt.position, ".") return nil, false } start := p.pt p.read() p.failAt(true, start.position, ".") return p.sliceFrom(start), true } func (p *parser) parseCharClassMatcher(chr *charClassMatcher) (interface{}, bool) { if p.debug { defer p.out(p.in("parseCharClassMatcher")) } cur := p.pt.rn start := p.pt // can't match EOF if cur == utf8.RuneError && p.pt.w == 0 { // see utf8.DecodeRune p.failAt(false, start.position, chr.val) return nil, false } if chr.ignoreCase { cur = unicode.ToLower(cur) } // try to match in the list of available chars for _, rn := range chr.chars { if rn == cur { if chr.inverted { p.failAt(false, start.position, chr.val) return nil, false } p.read() p.failAt(true, start.position, chr.val) return p.sliceFrom(start), true } } // try to match in the list of ranges for i := 0; i < len(chr.ranges); i += 2 { if cur >= chr.ranges[i] && cur <= chr.ranges[i+1] { if chr.inverted { p.failAt(false, start.position, chr.val) return nil, false } p.read() p.failAt(true, start.position, chr.val) return p.sliceFrom(start), true } } // try to match in the list of Unicode classes for _, cl := range chr.classes { if unicode.Is(cl, cur) { if chr.inverted { p.failAt(false, start.position, chr.val) return nil, false } p.read() p.failAt(true, start.position, chr.val) return p.sliceFrom(start), true } } if chr.inverted { p.read() p.failAt(true, start.position, chr.val) return p.sliceFrom(start), true } p.failAt(false, start.position, chr.val) return nil, false } func (p *parser) incChoiceAltCnt(ch *choiceExpr, altI int) { choiceIdent := fmt.Sprintf("%s %d:%d", p.rstack[len(p.rstack)-1].name, ch.pos.line, ch.pos.col) m := p.ChoiceAltCnt[choiceIdent] if m == nil { m = make(map[string]int) p.ChoiceAltCnt[choiceIdent] = m } // We increment altI by 1, so the keys do not start at 0 alt := strconv.Itoa(altI + 1) if altI == choiceNoMatch { alt = p.choiceNoMatch } m[alt]++ } func (p *parser) parseChoiceExpr(ch *choiceExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseChoiceExpr")) } for altI, alt := range ch.alternatives { // dummy assignment to prevent compile error if optimized _ = altI state := p.cloneState() p.pushV() val, ok := p.parseExpr(alt) p.popV() if ok { p.incChoiceAltCnt(ch, altI) return val, ok } p.restoreState(state) } p.incChoiceAltCnt(ch, choiceNoMatch) return nil, false } func (p *parser) parseLabeledExpr(lab *labeledExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseLabeledExpr")) } p.pushV() val, ok := p.parseExpr(lab.expr) p.popV() if ok && lab.label != "" { m := p.vstack[len(p.vstack)-1] m[lab.label] = val } return val, ok } func (p *parser) parseLitMatcher(lit *litMatcher) (interface{}, bool) { if p.debug { defer p.out(p.in("parseLitMatcher")) } start := p.pt for _, want := range lit.val { cur := p.pt.rn if lit.ignoreCase { cur = unicode.ToLower(cur) } if cur != want { p.failAt(false, start.position, lit.want) p.restore(start) return nil, false } p.read() } p.failAt(true, start.position, lit.want) return p.sliceFrom(start), true } func (p *parser) parseNotCodeExpr(not *notCodeExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseNotCodeExpr")) } state := p.cloneState() ok, err := not.run(p) if err != nil { p.addErr(err) } p.restoreState(state) return nil, !ok } func (p *parser) parseNotExpr(not *notExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseNotExpr")) } pt := p.pt state := p.cloneState() p.pushV() p.maxFailInvertExpected = !p.maxFailInvertExpected _, ok := p.parseExpr(not.expr) p.maxFailInvertExpected = !p.maxFailInvertExpected p.popV() p.restoreState(state) p.restore(pt) return nil, !ok } func (p *parser) parseOneOrMoreExpr(expr *oneOrMoreExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseOneOrMoreExpr")) } var vals []interface{} for { p.pushV() val, ok := p.parseExpr(expr.expr) p.popV() if !ok { if len(vals) == 0 { // did not match once, no match return nil, false } return vals, true } vals = append(vals, val) } } func (p *parser) parseRecoveryExpr(recover *recoveryExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseRecoveryExpr (" + strings.Join(recover.failureLabel, ",") + ")")) } p.pushRecovery(recover.failureLabel, recover.recoverExpr) val, ok := p.parseExpr(recover.expr) p.popRecovery() return val, ok } func (p *parser) parseRuleRefExpr(ref *ruleRefExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseRuleRefExpr " + ref.name)) } if ref.name == "" { panic(fmt.Sprintf("%s: invalid rule: missing name", ref.pos)) } rule := p.rules[ref.name] if rule == nil { p.addErr(fmt.Errorf("undefined rule: %s", ref.name)) return nil, false } return p.parseRule(rule) } func (p *parser) parseSeqExpr(seq *seqExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseSeqExpr")) } vals := make([]interface{}, 0, len(seq.exprs)) pt := p.pt state := p.cloneState() for _, expr := range seq.exprs { val, ok := p.parseExpr(expr) if !ok { p.restoreState(state) p.restore(pt) return nil, false } vals = append(vals, val) } return vals, true } func (p *parser) parseStateCodeExpr(state *stateCodeExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseStateCodeExpr")) } err := state.run(p) if err != nil { p.addErr(err) } return nil, true } func (p *parser) parseThrowExpr(expr *throwExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseThrowExpr")) } for i := len(p.recoveryStack) - 1; i >= 0; i-- { if recoverExpr, ok := p.recoveryStack[i][expr.label]; ok { if val, ok := p.parseExpr(recoverExpr); ok { return val, ok } } } return nil, false } func (p *parser) parseZeroOrMoreExpr(expr *zeroOrMoreExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseZeroOrMoreExpr")) } var vals []interface{} for { p.pushV() val, ok := p.parseExpr(expr.expr) p.popV() if !ok { return vals, true } vals = append(vals, val) } } func (p *parser) parseZeroOrOneExpr(expr *zeroOrOneExpr) (interface{}, bool) { if p.debug { defer p.out(p.in("parseZeroOrOneExpr")) } p.pushV() val, _ := p.parseExpr(expr.expr) p.popV() // whether it matched or not, consider it a match return val, true }