mirror of
https://github.com/cheat/cheat.git
synced 2024-11-01 13:41:01 +01:00
2214 lines
49 KiB
Go
2214 lines
49 KiB
Go
package syntax
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import (
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"fmt"
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"math"
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"os"
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"sort"
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"strconv"
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"unicode"
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)
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type RegexOptions int32
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const (
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IgnoreCase RegexOptions = 0x0001 // "i"
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Multiline = 0x0002 // "m"
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ExplicitCapture = 0x0004 // "n"
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Compiled = 0x0008 // "c"
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Singleline = 0x0010 // "s"
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IgnorePatternWhitespace = 0x0020 // "x"
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RightToLeft = 0x0040 // "r"
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Debug = 0x0080 // "d"
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ECMAScript = 0x0100 // "e"
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RE2 = 0x0200 // RE2 compat mode
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)
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func optionFromCode(ch rune) RegexOptions {
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// case-insensitive
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switch ch {
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case 'i', 'I':
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return IgnoreCase
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case 'r', 'R':
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return RightToLeft
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case 'm', 'M':
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return Multiline
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case 'n', 'N':
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return ExplicitCapture
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case 's', 'S':
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return Singleline
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case 'x', 'X':
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return IgnorePatternWhitespace
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case 'd', 'D':
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return Debug
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case 'e', 'E':
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return ECMAScript
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default:
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return 0
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}
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}
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// An Error describes a failure to parse a regular expression
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// and gives the offending expression.
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type Error struct {
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Code ErrorCode
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Expr string
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Args []interface{}
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}
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func (e *Error) Error() string {
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if len(e.Args) == 0 {
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return "error parsing regexp: " + e.Code.String() + " in `" + e.Expr + "`"
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}
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return "error parsing regexp: " + fmt.Sprintf(e.Code.String(), e.Args...) + " in `" + e.Expr + "`"
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}
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// An ErrorCode describes a failure to parse a regular expression.
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type ErrorCode string
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const (
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// internal issue
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ErrInternalError ErrorCode = "regexp/syntax: internal error"
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// Parser errors
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ErrUnterminatedComment = "unterminated comment"
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ErrInvalidCharRange = "invalid character class range"
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ErrInvalidRepeatSize = "invalid repeat count"
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ErrInvalidUTF8 = "invalid UTF-8"
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ErrCaptureGroupOutOfRange = "capture group number out of range"
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ErrUnexpectedParen = "unexpected )"
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ErrMissingParen = "missing closing )"
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ErrMissingBrace = "missing closing }"
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ErrInvalidRepeatOp = "invalid nested repetition operator"
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ErrMissingRepeatArgument = "missing argument to repetition operator"
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ErrConditionalExpression = "illegal conditional (?(...)) expression"
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ErrTooManyAlternates = "too many | in (?()|)"
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ErrUnrecognizedGrouping = "unrecognized grouping construct: (%v"
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ErrInvalidGroupName = "invalid group name: group names must begin with a word character and have a matching terminator"
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ErrCapNumNotZero = "capture number cannot be zero"
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ErrUndefinedBackRef = "reference to undefined group number %v"
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ErrUndefinedNameRef = "reference to undefined group name %v"
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ErrAlternationCantCapture = "alternation conditions do not capture and cannot be named"
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ErrAlternationCantHaveComment = "alternation conditions cannot be comments"
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ErrMalformedReference = "(?(%v) ) malformed"
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ErrUndefinedReference = "(?(%v) ) reference to undefined group"
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ErrIllegalEndEscape = "illegal \\ at end of pattern"
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ErrMalformedSlashP = "malformed \\p{X} character escape"
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ErrIncompleteSlashP = "incomplete \\p{X} character escape"
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ErrUnknownSlashP = "unknown unicode category, script, or property '%v'"
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ErrUnrecognizedEscape = "unrecognized escape sequence \\%v"
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ErrMissingControl = "missing control character"
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ErrUnrecognizedControl = "unrecognized control character"
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ErrTooFewHex = "insufficient hexadecimal digits"
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ErrInvalidHex = "hex values may not be larger than 0x10FFFF"
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ErrMalformedNameRef = "malformed \\k<...> named back reference"
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ErrBadClassInCharRange = "cannot include class \\%v in character range"
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ErrUnterminatedBracket = "unterminated [] set"
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ErrSubtractionMustBeLast = "a subtraction must be the last element in a character class"
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ErrReversedCharRange = "[x-y] range in reverse order"
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)
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func (e ErrorCode) String() string {
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return string(e)
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}
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type parser struct {
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stack *regexNode
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group *regexNode
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alternation *regexNode
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concatenation *regexNode
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unit *regexNode
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patternRaw string
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pattern []rune
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currentPos int
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specialCase *unicode.SpecialCase
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autocap int
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capcount int
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captop int
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capsize int
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caps map[int]int
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capnames map[string]int
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capnumlist []int
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capnamelist []string
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options RegexOptions
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optionsStack []RegexOptions
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ignoreNextParen bool
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}
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const (
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maxValueDiv10 int = math.MaxInt32 / 10
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maxValueMod10 = math.MaxInt32 % 10
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)
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// Parse converts a regex string into a parse tree
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func Parse(re string, op RegexOptions) (*RegexTree, error) {
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p := parser{
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options: op,
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caps: make(map[int]int),
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}
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p.setPattern(re)
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if err := p.countCaptures(); err != nil {
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return nil, err
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}
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p.reset(op)
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root, err := p.scanRegex()
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if err != nil {
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return nil, err
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}
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tree := &RegexTree{
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root: root,
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caps: p.caps,
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capnumlist: p.capnumlist,
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captop: p.captop,
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Capnames: p.capnames,
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Caplist: p.capnamelist,
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options: op,
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}
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if tree.options&Debug > 0 {
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os.Stdout.WriteString(tree.Dump())
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}
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return tree, nil
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}
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func (p *parser) setPattern(pattern string) {
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p.patternRaw = pattern
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p.pattern = make([]rune, 0, len(pattern))
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//populate our rune array to handle utf8 encoding
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for _, r := range pattern {
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p.pattern = append(p.pattern, r)
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}
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}
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func (p *parser) getErr(code ErrorCode, args ...interface{}) error {
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return &Error{Code: code, Expr: p.patternRaw, Args: args}
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}
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func (p *parser) noteCaptureSlot(i, pos int) {
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if _, ok := p.caps[i]; !ok {
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// the rhs of the hashtable isn't used in the parser
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p.caps[i] = pos
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p.capcount++
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if p.captop <= i {
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if i == math.MaxInt32 {
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p.captop = i
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} else {
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p.captop = i + 1
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}
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}
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}
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}
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func (p *parser) noteCaptureName(name string, pos int) {
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if p.capnames == nil {
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p.capnames = make(map[string]int)
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}
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if _, ok := p.capnames[name]; !ok {
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p.capnames[name] = pos
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p.capnamelist = append(p.capnamelist, name)
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}
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}
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func (p *parser) assignNameSlots() {
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if p.capnames != nil {
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for _, name := range p.capnamelist {
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for p.isCaptureSlot(p.autocap) {
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p.autocap++
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}
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pos := p.capnames[name]
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p.capnames[name] = p.autocap
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p.noteCaptureSlot(p.autocap, pos)
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p.autocap++
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}
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}
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// if the caps array has at least one gap, construct the list of used slots
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if p.capcount < p.captop {
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p.capnumlist = make([]int, p.capcount)
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i := 0
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for k := range p.caps {
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p.capnumlist[i] = k
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i++
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}
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sort.Ints(p.capnumlist)
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}
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// merge capsnumlist into capnamelist
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if p.capnames != nil || p.capnumlist != nil {
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var oldcapnamelist []string
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var next int
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var k int
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if p.capnames == nil {
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oldcapnamelist = nil
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p.capnames = make(map[string]int)
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p.capnamelist = []string{}
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next = -1
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} else {
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oldcapnamelist = p.capnamelist
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p.capnamelist = []string{}
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next = p.capnames[oldcapnamelist[0]]
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}
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for i := 0; i < p.capcount; i++ {
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j := i
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if p.capnumlist != nil {
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j = p.capnumlist[i]
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}
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if next == j {
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p.capnamelist = append(p.capnamelist, oldcapnamelist[k])
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k++
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if k == len(oldcapnamelist) {
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next = -1
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} else {
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next = p.capnames[oldcapnamelist[k]]
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}
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} else {
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//feature: culture?
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str := strconv.Itoa(j)
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p.capnamelist = append(p.capnamelist, str)
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p.capnames[str] = j
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}
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}
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}
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}
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func (p *parser) consumeAutocap() int {
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r := p.autocap
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p.autocap++
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return r
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}
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// CountCaptures is a prescanner for deducing the slots used for
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// captures by doing a partial tokenization of the pattern.
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func (p *parser) countCaptures() error {
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var ch rune
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p.noteCaptureSlot(0, 0)
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p.autocap = 1
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for p.charsRight() > 0 {
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pos := p.textpos()
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ch = p.moveRightGetChar()
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switch ch {
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case '\\':
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if p.charsRight() > 0 {
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p.scanBackslash(true)
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}
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case '#':
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if p.useOptionX() {
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p.moveLeft()
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p.scanBlank()
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}
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case '[':
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p.scanCharSet(false, true)
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case ')':
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if !p.emptyOptionsStack() {
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p.popOptions()
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}
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case '(':
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if p.charsRight() >= 2 && p.rightChar(1) == '#' && p.rightChar(0) == '?' {
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p.moveLeft()
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p.scanBlank()
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} else {
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p.pushOptions()
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if p.charsRight() > 0 && p.rightChar(0) == '?' {
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// we have (?...
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p.moveRight(1)
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if p.charsRight() > 1 && (p.rightChar(0) == '<' || p.rightChar(0) == '\'') {
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// named group: (?<... or (?'...
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p.moveRight(1)
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ch = p.rightChar(0)
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if ch != '0' && IsWordChar(ch) {
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if ch >= '1' && ch <= '9' {
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dec, err := p.scanDecimal()
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if err != nil {
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return err
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}
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p.noteCaptureSlot(dec, pos)
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} else {
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p.noteCaptureName(p.scanCapname(), pos)
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}
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}
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} else if p.useRE2() && p.charsRight() > 2 && (p.rightChar(0) == 'P' && p.rightChar(1) == '<') {
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// RE2-compat (?P<)
|
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p.moveRight(2)
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ch = p.rightChar(0)
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if IsWordChar(ch) {
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p.noteCaptureName(p.scanCapname(), pos)
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}
|
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} else {
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// (?...
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// get the options if it's an option construct (?cimsx-cimsx...)
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p.scanOptions()
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if p.charsRight() > 0 {
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if p.rightChar(0) == ')' {
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// (?cimsx-cimsx)
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p.moveRight(1)
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p.popKeepOptions()
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} else if p.rightChar(0) == '(' {
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// alternation construct: (?(foo)yes|no)
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// ignore the next paren so we don't capture the condition
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p.ignoreNextParen = true
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// break from here so we don't reset ignoreNextParen
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continue
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}
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}
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}
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} else {
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if !p.useOptionN() && !p.ignoreNextParen {
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p.noteCaptureSlot(p.consumeAutocap(), pos)
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}
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}
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}
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p.ignoreNextParen = false
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}
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}
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p.assignNameSlots()
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return nil
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}
|
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func (p *parser) reset(topopts RegexOptions) {
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p.currentPos = 0
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p.autocap = 1
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p.ignoreNextParen = false
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if len(p.optionsStack) > 0 {
|
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p.optionsStack = p.optionsStack[:0]
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}
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p.options = topopts
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p.stack = nil
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}
|
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|
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func (p *parser) scanRegex() (*regexNode, error) {
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ch := '@' // nonspecial ch, means at beginning
|
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isQuant := false
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|
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p.startGroup(newRegexNodeMN(ntCapture, p.options, 0, -1))
|
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|
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for p.charsRight() > 0 {
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wasPrevQuantifier := isQuant
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isQuant = false
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|
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if err := p.scanBlank(); err != nil {
|
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return nil, err
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}
|
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|
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startpos := p.textpos()
|
|
|
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// move past all of the normal characters. We'll stop when we hit some kind of control character,
|
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// or if IgnorePatternWhiteSpace is on, we'll stop when we see some whitespace.
|
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if p.useOptionX() {
|
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for p.charsRight() > 0 {
|
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ch = p.rightChar(0)
|
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//UGLY: clean up, this is ugly
|
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if !(!isStopperX(ch) || (ch == '{' && !p.isTrueQuantifier())) {
|
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break
|
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}
|
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p.moveRight(1)
|
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}
|
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} else {
|
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for p.charsRight() > 0 {
|
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ch = p.rightChar(0)
|
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if !(!isSpecial(ch) || ch == '{' && !p.isTrueQuantifier()) {
|
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break
|
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}
|
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p.moveRight(1)
|
|
}
|
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}
|
|
|
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endpos := p.textpos()
|
|
|
|
p.scanBlank()
|
|
|
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if p.charsRight() == 0 {
|
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ch = '!' // nonspecial, means at end
|
|
} else if ch = p.rightChar(0); isSpecial(ch) {
|
|
isQuant = isQuantifier(ch)
|
|
p.moveRight(1)
|
|
} else {
|
|
ch = ' ' // nonspecial, means at ordinary char
|
|
}
|
|
|
|
if startpos < endpos {
|
|
cchUnquantified := endpos - startpos
|
|
if isQuant {
|
|
cchUnquantified--
|
|
}
|
|
wasPrevQuantifier = false
|
|
|
|
if cchUnquantified > 0 {
|
|
p.addToConcatenate(startpos, cchUnquantified, false)
|
|
}
|
|
|
|
if isQuant {
|
|
p.addUnitOne(p.charAt(endpos - 1))
|
|
}
|
|
}
|
|
|
|
switch ch {
|
|
case '!':
|
|
goto BreakOuterScan
|
|
|
|
case ' ':
|
|
goto ContinueOuterScan
|
|
|
|
case '[':
|
|
cc, err := p.scanCharSet(p.useOptionI(), false)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
p.addUnitSet(cc)
|
|
|
|
case '(':
|
|
p.pushOptions()
|
|
|
|
if grouper, err := p.scanGroupOpen(); err != nil {
|
|
return nil, err
|
|
} else if grouper == nil {
|
|
p.popKeepOptions()
|
|
} else {
|
|
p.pushGroup()
|
|
p.startGroup(grouper)
|
|
}
|
|
|
|
continue
|
|
|
|
case '|':
|
|
p.addAlternate()
|
|
goto ContinueOuterScan
|
|
|
|
case ')':
|
|
if p.emptyStack() {
|
|
return nil, p.getErr(ErrUnexpectedParen)
|
|
}
|
|
|
|
if err := p.addGroup(); err != nil {
|
|
return nil, err
|
|
}
|
|
if err := p.popGroup(); err != nil {
|
|
return nil, err
|
|
}
|
|
p.popOptions()
|
|
|
|
if p.unit == nil {
|
|
goto ContinueOuterScan
|
|
}
|
|
|
|
case '\\':
|
|
n, err := p.scanBackslash(false)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
p.addUnitNode(n)
|
|
|
|
case '^':
|
|
if p.useOptionM() {
|
|
p.addUnitType(ntBol)
|
|
} else {
|
|
p.addUnitType(ntBeginning)
|
|
}
|
|
|
|
case '$':
|
|
if p.useOptionM() {
|
|
p.addUnitType(ntEol)
|
|
} else {
|
|
p.addUnitType(ntEndZ)
|
|
}
|
|
|
|
case '.':
|
|
if p.useOptionE() {
|
|
p.addUnitSet(ECMAAnyClass())
|
|
} else if p.useOptionS() {
|
|
p.addUnitSet(AnyClass())
|
|
} else {
|
|
p.addUnitNotone('\n')
|
|
}
|
|
|
|
case '{', '*', '+', '?':
|
|
if p.unit == nil {
|
|
if wasPrevQuantifier {
|
|
return nil, p.getErr(ErrInvalidRepeatOp)
|
|
} else {
|
|
return nil, p.getErr(ErrMissingRepeatArgument)
|
|
}
|
|
}
|
|
p.moveLeft()
|
|
|
|
default:
|
|
return nil, p.getErr(ErrInternalError)
|
|
}
|
|
|
|
if err := p.scanBlank(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if p.charsRight() > 0 {
|
|
isQuant = p.isTrueQuantifier()
|
|
}
|
|
if p.charsRight() == 0 || !isQuant {
|
|
//maintain odd C# assignment order -- not sure if required, could clean up?
|
|
p.addConcatenate()
|
|
goto ContinueOuterScan
|
|
}
|
|
|
|
ch = p.moveRightGetChar()
|
|
|
|
// Handle quantifiers
|
|
for p.unit != nil {
|
|
var min, max int
|
|
var lazy bool
|
|
|
|
switch ch {
|
|
case '*':
|
|
min = 0
|
|
max = math.MaxInt32
|
|
|
|
case '?':
|
|
min = 0
|
|
max = 1
|
|
|
|
case '+':
|
|
min = 1
|
|
max = math.MaxInt32
|
|
|
|
case '{':
|
|
{
|
|
var err error
|
|
startpos = p.textpos()
|
|
if min, err = p.scanDecimal(); err != nil {
|
|
return nil, err
|
|
}
|
|
max = min
|
|
if startpos < p.textpos() {
|
|
if p.charsRight() > 0 && p.rightChar(0) == ',' {
|
|
p.moveRight(1)
|
|
if p.charsRight() == 0 || p.rightChar(0) == '}' {
|
|
max = math.MaxInt32
|
|
} else {
|
|
if max, err = p.scanDecimal(); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if startpos == p.textpos() || p.charsRight() == 0 || p.moveRightGetChar() != '}' {
|
|
p.addConcatenate()
|
|
p.textto(startpos - 1)
|
|
goto ContinueOuterScan
|
|
}
|
|
}
|
|
|
|
default:
|
|
return nil, p.getErr(ErrInternalError)
|
|
}
|
|
|
|
if err := p.scanBlank(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if p.charsRight() == 0 || p.rightChar(0) != '?' {
|
|
lazy = false
|
|
} else {
|
|
p.moveRight(1)
|
|
lazy = true
|
|
}
|
|
|
|
if min > max {
|
|
return nil, p.getErr(ErrInvalidRepeatSize)
|
|
}
|
|
|
|
p.addConcatenate3(lazy, min, max)
|
|
}
|
|
|
|
ContinueOuterScan:
|
|
}
|
|
|
|
BreakOuterScan:
|
|
;
|
|
|
|
if !p.emptyStack() {
|
|
return nil, p.getErr(ErrMissingParen)
|
|
}
|
|
|
|
if err := p.addGroup(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return p.unit, nil
|
|
|
|
}
|
|
|
|
/*
|
|
* Simple parsing for replacement patterns
|
|
*/
|
|
func (p *parser) scanReplacement() (*regexNode, error) {
|
|
var c, startpos int
|
|
|
|
p.concatenation = newRegexNode(ntConcatenate, p.options)
|
|
|
|
for {
|
|
c = p.charsRight()
|
|
if c == 0 {
|
|
break
|
|
}
|
|
|
|
startpos = p.textpos()
|
|
|
|
for c > 0 && p.rightChar(0) != '$' {
|
|
p.moveRight(1)
|
|
c--
|
|
}
|
|
|
|
p.addToConcatenate(startpos, p.textpos()-startpos, true)
|
|
|
|
if c > 0 {
|
|
if p.moveRightGetChar() == '$' {
|
|
n, err := p.scanDollar()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
p.addUnitNode(n)
|
|
}
|
|
p.addConcatenate()
|
|
}
|
|
}
|
|
|
|
return p.concatenation, nil
|
|
}
|
|
|
|
/*
|
|
* Scans $ patterns recognized within replacement patterns
|
|
*/
|
|
func (p *parser) scanDollar() (*regexNode, error) {
|
|
if p.charsRight() == 0 {
|
|
return newRegexNodeCh(ntOne, p.options, '$'), nil
|
|
}
|
|
|
|
ch := p.rightChar(0)
|
|
angled := false
|
|
backpos := p.textpos()
|
|
lastEndPos := backpos
|
|
|
|
// Note angle
|
|
|
|
if ch == '{' && p.charsRight() > 1 {
|
|
angled = true
|
|
p.moveRight(1)
|
|
ch = p.rightChar(0)
|
|
}
|
|
|
|
// Try to parse backreference: \1 or \{1} or \{cap}
|
|
|
|
if ch >= '0' && ch <= '9' {
|
|
if !angled && p.useOptionE() {
|
|
capnum := -1
|
|
newcapnum := int(ch - '0')
|
|
p.moveRight(1)
|
|
if p.isCaptureSlot(newcapnum) {
|
|
capnum = newcapnum
|
|
lastEndPos = p.textpos()
|
|
}
|
|
|
|
for p.charsRight() > 0 {
|
|
ch = p.rightChar(0)
|
|
if ch < '0' || ch > '9' {
|
|
break
|
|
}
|
|
digit := int(ch - '0')
|
|
if newcapnum > maxValueDiv10 || (newcapnum == maxValueDiv10 && digit > maxValueMod10) {
|
|
return nil, p.getErr(ErrCaptureGroupOutOfRange)
|
|
}
|
|
|
|
newcapnum = newcapnum*10 + digit
|
|
|
|
p.moveRight(1)
|
|
if p.isCaptureSlot(newcapnum) {
|
|
capnum = newcapnum
|
|
lastEndPos = p.textpos()
|
|
}
|
|
}
|
|
p.textto(lastEndPos)
|
|
if capnum >= 0 {
|
|
return newRegexNodeM(ntRef, p.options, capnum), nil
|
|
}
|
|
} else {
|
|
capnum, err := p.scanDecimal()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if !angled || p.charsRight() > 0 && p.moveRightGetChar() == '}' {
|
|
if p.isCaptureSlot(capnum) {
|
|
return newRegexNodeM(ntRef, p.options, capnum), nil
|
|
}
|
|
}
|
|
}
|
|
} else if angled && IsWordChar(ch) {
|
|
capname := p.scanCapname()
|
|
|
|
if p.charsRight() > 0 && p.moveRightGetChar() == '}' {
|
|
if p.isCaptureName(capname) {
|
|
return newRegexNodeM(ntRef, p.options, p.captureSlotFromName(capname)), nil
|
|
}
|
|
}
|
|
} else if !angled {
|
|
capnum := 1
|
|
|
|
switch ch {
|
|
case '$':
|
|
p.moveRight(1)
|
|
return newRegexNodeCh(ntOne, p.options, '$'), nil
|
|
case '&':
|
|
capnum = 0
|
|
case '`':
|
|
capnum = replaceLeftPortion
|
|
case '\'':
|
|
capnum = replaceRightPortion
|
|
case '+':
|
|
capnum = replaceLastGroup
|
|
case '_':
|
|
capnum = replaceWholeString
|
|
}
|
|
|
|
if capnum != 1 {
|
|
p.moveRight(1)
|
|
return newRegexNodeM(ntRef, p.options, capnum), nil
|
|
}
|
|
}
|
|
|
|
// unrecognized $: literalize
|
|
|
|
p.textto(backpos)
|
|
return newRegexNodeCh(ntOne, p.options, '$'), nil
|
|
}
|
|
|
|
// scanGroupOpen scans chars following a '(' (not counting the '('), and returns
|
|
// a RegexNode for the type of group scanned, or nil if the group
|
|
// simply changed options (?cimsx-cimsx) or was a comment (#...).
|
|
func (p *parser) scanGroupOpen() (*regexNode, error) {
|
|
var ch rune
|
|
var nt nodeType
|
|
var err error
|
|
close := '>'
|
|
start := p.textpos()
|
|
|
|
// just return a RegexNode if we have:
|
|
// 1. "(" followed by nothing
|
|
// 2. "(x" where x != ?
|
|
// 3. "(?)"
|
|
if p.charsRight() == 0 || p.rightChar(0) != '?' || (p.rightChar(0) == '?' && (p.charsRight() > 1 && p.rightChar(1) == ')')) {
|
|
if p.useOptionN() || p.ignoreNextParen {
|
|
p.ignoreNextParen = false
|
|
return newRegexNode(ntGroup, p.options), nil
|
|
}
|
|
return newRegexNodeMN(ntCapture, p.options, p.consumeAutocap(), -1), nil
|
|
}
|
|
|
|
p.moveRight(1)
|
|
|
|
for {
|
|
if p.charsRight() == 0 {
|
|
break
|
|
}
|
|
|
|
switch ch = p.moveRightGetChar(); ch {
|
|
case ':':
|
|
nt = ntGroup
|
|
|
|
case '=':
|
|
p.options &= ^RightToLeft
|
|
nt = ntRequire
|
|
|
|
case '!':
|
|
p.options &= ^RightToLeft
|
|
nt = ntPrevent
|
|
|
|
case '>':
|
|
nt = ntGreedy
|
|
|
|
case '\'':
|
|
close = '\''
|
|
fallthrough
|
|
|
|
case '<':
|
|
if p.charsRight() == 0 {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
switch ch = p.moveRightGetChar(); ch {
|
|
case '=':
|
|
if close == '\'' {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
p.options |= RightToLeft
|
|
nt = ntRequire
|
|
|
|
case '!':
|
|
if close == '\'' {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
p.options |= RightToLeft
|
|
nt = ntPrevent
|
|
|
|
default:
|
|
p.moveLeft()
|
|
capnum := -1
|
|
uncapnum := -1
|
|
proceed := false
|
|
|
|
// grab part before -
|
|
|
|
if ch >= '0' && ch <= '9' {
|
|
if capnum, err = p.scanDecimal(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if !p.isCaptureSlot(capnum) {
|
|
capnum = -1
|
|
}
|
|
|
|
// check if we have bogus characters after the number
|
|
if p.charsRight() > 0 && !(p.rightChar(0) == close || p.rightChar(0) == '-') {
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
if capnum == 0 {
|
|
return nil, p.getErr(ErrCapNumNotZero)
|
|
}
|
|
} else if IsWordChar(ch) {
|
|
capname := p.scanCapname()
|
|
|
|
if p.isCaptureName(capname) {
|
|
capnum = p.captureSlotFromName(capname)
|
|
}
|
|
|
|
// check if we have bogus character after the name
|
|
if p.charsRight() > 0 && !(p.rightChar(0) == close || p.rightChar(0) == '-') {
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
} else if ch == '-' {
|
|
proceed = true
|
|
} else {
|
|
// bad group name - starts with something other than a word character and isn't a number
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
|
|
// grab part after - if any
|
|
|
|
if (capnum != -1 || proceed == true) && p.charsRight() > 0 && p.rightChar(0) == '-' {
|
|
p.moveRight(1)
|
|
|
|
//no more chars left, no closing char, etc
|
|
if p.charsRight() == 0 {
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
|
|
ch = p.rightChar(0)
|
|
if ch >= '0' && ch <= '9' {
|
|
if uncapnum, err = p.scanDecimal(); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if !p.isCaptureSlot(uncapnum) {
|
|
return nil, p.getErr(ErrUndefinedBackRef, uncapnum)
|
|
}
|
|
|
|
// check if we have bogus characters after the number
|
|
if p.charsRight() > 0 && p.rightChar(0) != close {
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
} else if IsWordChar(ch) {
|
|
uncapname := p.scanCapname()
|
|
|
|
if !p.isCaptureName(uncapname) {
|
|
return nil, p.getErr(ErrUndefinedNameRef, uncapname)
|
|
}
|
|
uncapnum = p.captureSlotFromName(uncapname)
|
|
|
|
// check if we have bogus character after the name
|
|
if p.charsRight() > 0 && p.rightChar(0) != close {
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
} else {
|
|
// bad group name - starts with something other than a word character and isn't a number
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
}
|
|
|
|
// actually make the node
|
|
|
|
if (capnum != -1 || uncapnum != -1) && p.charsRight() > 0 && p.moveRightGetChar() == close {
|
|
return newRegexNodeMN(ntCapture, p.options, capnum, uncapnum), nil
|
|
}
|
|
goto BreakRecognize
|
|
}
|
|
|
|
case '(':
|
|
// alternation construct (?(...) | )
|
|
|
|
parenPos := p.textpos()
|
|
if p.charsRight() > 0 {
|
|
ch = p.rightChar(0)
|
|
|
|
// check if the alternation condition is a backref
|
|
if ch >= '0' && ch <= '9' {
|
|
var capnum int
|
|
if capnum, err = p.scanDecimal(); err != nil {
|
|
return nil, err
|
|
}
|
|
if p.charsRight() > 0 && p.moveRightGetChar() == ')' {
|
|
if p.isCaptureSlot(capnum) {
|
|
return newRegexNodeM(ntTestref, p.options, capnum), nil
|
|
}
|
|
return nil, p.getErr(ErrUndefinedReference, capnum)
|
|
}
|
|
|
|
return nil, p.getErr(ErrMalformedReference, capnum)
|
|
|
|
} else if IsWordChar(ch) {
|
|
capname := p.scanCapname()
|
|
|
|
if p.isCaptureName(capname) && p.charsRight() > 0 && p.moveRightGetChar() == ')' {
|
|
return newRegexNodeM(ntTestref, p.options, p.captureSlotFromName(capname)), nil
|
|
}
|
|
}
|
|
}
|
|
// not a backref
|
|
nt = ntTestgroup
|
|
p.textto(parenPos - 1) // jump to the start of the parentheses
|
|
p.ignoreNextParen = true // but make sure we don't try to capture the insides
|
|
|
|
charsRight := p.charsRight()
|
|
if charsRight >= 3 && p.rightChar(1) == '?' {
|
|
rightchar2 := p.rightChar(2)
|
|
// disallow comments in the condition
|
|
if rightchar2 == '#' {
|
|
return nil, p.getErr(ErrAlternationCantHaveComment)
|
|
}
|
|
|
|
// disallow named capture group (?<..>..) in the condition
|
|
if rightchar2 == '\'' {
|
|
return nil, p.getErr(ErrAlternationCantCapture)
|
|
}
|
|
|
|
if charsRight >= 4 && (rightchar2 == '<' && p.rightChar(3) != '!' && p.rightChar(3) != '=') {
|
|
return nil, p.getErr(ErrAlternationCantCapture)
|
|
}
|
|
}
|
|
|
|
case 'P':
|
|
if p.useRE2() {
|
|
// support for P<name> syntax
|
|
if p.charsRight() < 3 {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
ch = p.moveRightGetChar()
|
|
if ch != '<' {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
ch = p.moveRightGetChar()
|
|
p.moveLeft()
|
|
|
|
if IsWordChar(ch) {
|
|
capnum := -1
|
|
capname := p.scanCapname()
|
|
|
|
if p.isCaptureName(capname) {
|
|
capnum = p.captureSlotFromName(capname)
|
|
}
|
|
|
|
// check if we have bogus character after the name
|
|
if p.charsRight() > 0 && p.rightChar(0) != '>' {
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
|
|
// actually make the node
|
|
|
|
if capnum != -1 && p.charsRight() > 0 && p.moveRightGetChar() == '>' {
|
|
return newRegexNodeMN(ntCapture, p.options, capnum, -1), nil
|
|
}
|
|
goto BreakRecognize
|
|
|
|
} else {
|
|
// bad group name - starts with something other than a word character and isn't a number
|
|
return nil, p.getErr(ErrInvalidGroupName)
|
|
}
|
|
}
|
|
// if we're not using RE2 compat mode then
|
|
// we just behave like normal
|
|
fallthrough
|
|
|
|
default:
|
|
p.moveLeft()
|
|
|
|
nt = ntGroup
|
|
// disallow options in the children of a testgroup node
|
|
if p.group.t != ntTestgroup {
|
|
p.scanOptions()
|
|
}
|
|
if p.charsRight() == 0 {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
if ch = p.moveRightGetChar(); ch == ')' {
|
|
return nil, nil
|
|
}
|
|
|
|
if ch != ':' {
|
|
goto BreakRecognize
|
|
}
|
|
|
|
}
|
|
|
|
return newRegexNode(nt, p.options), nil
|
|
}
|
|
|
|
BreakRecognize:
|
|
|
|
// break Recognize comes here
|
|
|
|
return nil, p.getErr(ErrUnrecognizedGrouping, string(p.pattern[start:p.textpos()]))
|
|
}
|
|
|
|
// scans backslash specials and basics
|
|
func (p *parser) scanBackslash(scanOnly bool) (*regexNode, error) {
|
|
|
|
if p.charsRight() == 0 {
|
|
return nil, p.getErr(ErrIllegalEndEscape)
|
|
}
|
|
|
|
switch ch := p.rightChar(0); ch {
|
|
case 'b', 'B', 'A', 'G', 'Z', 'z':
|
|
p.moveRight(1)
|
|
return newRegexNode(p.typeFromCode(ch), p.options), nil
|
|
|
|
case 'w':
|
|
p.moveRight(1)
|
|
if p.useOptionE() {
|
|
return newRegexNodeSet(ntSet, p.options, ECMAWordClass()), nil
|
|
}
|
|
return newRegexNodeSet(ntSet, p.options, WordClass()), nil
|
|
|
|
case 'W':
|
|
p.moveRight(1)
|
|
if p.useOptionE() {
|
|
return newRegexNodeSet(ntSet, p.options, NotECMAWordClass()), nil
|
|
}
|
|
return newRegexNodeSet(ntSet, p.options, NotWordClass()), nil
|
|
|
|
case 's':
|
|
p.moveRight(1)
|
|
if p.useOptionE() {
|
|
return newRegexNodeSet(ntSet, p.options, ECMASpaceClass()), nil
|
|
}
|
|
return newRegexNodeSet(ntSet, p.options, SpaceClass()), nil
|
|
|
|
case 'S':
|
|
p.moveRight(1)
|
|
if p.useOptionE() {
|
|
return newRegexNodeSet(ntSet, p.options, NotECMASpaceClass()), nil
|
|
}
|
|
return newRegexNodeSet(ntSet, p.options, NotSpaceClass()), nil
|
|
|
|
case 'd':
|
|
p.moveRight(1)
|
|
if p.useOptionE() {
|
|
return newRegexNodeSet(ntSet, p.options, ECMADigitClass()), nil
|
|
}
|
|
return newRegexNodeSet(ntSet, p.options, DigitClass()), nil
|
|
|
|
case 'D':
|
|
p.moveRight(1)
|
|
if p.useOptionE() {
|
|
return newRegexNodeSet(ntSet, p.options, NotECMADigitClass()), nil
|
|
}
|
|
return newRegexNodeSet(ntSet, p.options, NotDigitClass()), nil
|
|
|
|
case 'p', 'P':
|
|
p.moveRight(1)
|
|
prop, err := p.parseProperty()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cc := &CharSet{}
|
|
cc.addCategory(prop, (ch != 'p'), p.useOptionI(), p.patternRaw)
|
|
if p.useOptionI() {
|
|
cc.addLowercase()
|
|
}
|
|
|
|
return newRegexNodeSet(ntSet, p.options, cc), nil
|
|
|
|
default:
|
|
return p.scanBasicBackslash(scanOnly)
|
|
}
|
|
}
|
|
|
|
// Scans \-style backreferences and character escapes
|
|
func (p *parser) scanBasicBackslash(scanOnly bool) (*regexNode, error) {
|
|
if p.charsRight() == 0 {
|
|
return nil, p.getErr(ErrIllegalEndEscape)
|
|
}
|
|
angled := false
|
|
close := '\x00'
|
|
|
|
backpos := p.textpos()
|
|
ch := p.rightChar(0)
|
|
|
|
// allow \k<foo> instead of \<foo>, which is now deprecated
|
|
|
|
if ch == 'k' {
|
|
if p.charsRight() >= 2 {
|
|
p.moveRight(1)
|
|
ch = p.moveRightGetChar()
|
|
|
|
if ch == '<' || ch == '\'' {
|
|
angled = true
|
|
if ch == '\'' {
|
|
close = '\''
|
|
} else {
|
|
close = '>'
|
|
}
|
|
}
|
|
}
|
|
|
|
if !angled || p.charsRight() <= 0 {
|
|
return nil, p.getErr(ErrMalformedNameRef)
|
|
}
|
|
|
|
ch = p.rightChar(0)
|
|
|
|
} else if (ch == '<' || ch == '\'') && p.charsRight() > 1 { // Note angle without \g
|
|
angled = true
|
|
if ch == '\'' {
|
|
close = '\''
|
|
} else {
|
|
close = '>'
|
|
}
|
|
|
|
p.moveRight(1)
|
|
ch = p.rightChar(0)
|
|
}
|
|
|
|
// Try to parse backreference: \<1> or \<cap>
|
|
|
|
if angled && ch >= '0' && ch <= '9' {
|
|
capnum, err := p.scanDecimal()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if p.charsRight() > 0 && p.moveRightGetChar() == close {
|
|
if p.isCaptureSlot(capnum) {
|
|
return newRegexNodeM(ntRef, p.options, capnum), nil
|
|
}
|
|
return nil, p.getErr(ErrUndefinedBackRef, capnum)
|
|
}
|
|
} else if !angled && ch >= '1' && ch <= '9' { // Try to parse backreference or octal: \1
|
|
capnum, err := p.scanDecimal()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if scanOnly {
|
|
return nil, nil
|
|
}
|
|
|
|
if p.isCaptureSlot(capnum) {
|
|
return newRegexNodeM(ntRef, p.options, capnum), nil
|
|
}
|
|
if capnum <= 9 && !p.useOptionE() {
|
|
return nil, p.getErr(ErrUndefinedBackRef, capnum)
|
|
}
|
|
|
|
} else if angled && IsWordChar(ch) {
|
|
capname := p.scanCapname()
|
|
|
|
if p.charsRight() > 0 && p.moveRightGetChar() == close {
|
|
if p.isCaptureName(capname) {
|
|
return newRegexNodeM(ntRef, p.options, p.captureSlotFromName(capname)), nil
|
|
}
|
|
return nil, p.getErr(ErrUndefinedNameRef, capname)
|
|
}
|
|
}
|
|
|
|
// Not backreference: must be char code
|
|
|
|
p.textto(backpos)
|
|
ch, err := p.scanCharEscape()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if p.useOptionI() {
|
|
ch = unicode.ToLower(ch)
|
|
}
|
|
|
|
return newRegexNodeCh(ntOne, p.options, ch), nil
|
|
}
|
|
|
|
// Scans X for \p{X} or \P{X}
|
|
func (p *parser) parseProperty() (string, error) {
|
|
if p.charsRight() < 3 {
|
|
return "", p.getErr(ErrIncompleteSlashP)
|
|
}
|
|
ch := p.moveRightGetChar()
|
|
if ch != '{' {
|
|
return "", p.getErr(ErrMalformedSlashP)
|
|
}
|
|
|
|
startpos := p.textpos()
|
|
for p.charsRight() > 0 {
|
|
ch = p.moveRightGetChar()
|
|
if !(IsWordChar(ch) || ch == '-') {
|
|
p.moveLeft()
|
|
break
|
|
}
|
|
}
|
|
capname := string(p.pattern[startpos:p.textpos()])
|
|
|
|
if p.charsRight() == 0 || p.moveRightGetChar() != '}' {
|
|
return "", p.getErr(ErrIncompleteSlashP)
|
|
}
|
|
|
|
if !isValidUnicodeCat(capname) {
|
|
return "", p.getErr(ErrUnknownSlashP, capname)
|
|
}
|
|
|
|
return capname, nil
|
|
}
|
|
|
|
// Returns ReNode type for zero-length assertions with a \ code.
|
|
func (p *parser) typeFromCode(ch rune) nodeType {
|
|
switch ch {
|
|
case 'b':
|
|
if p.useOptionE() {
|
|
return ntECMABoundary
|
|
}
|
|
return ntBoundary
|
|
case 'B':
|
|
if p.useOptionE() {
|
|
return ntNonECMABoundary
|
|
}
|
|
return ntNonboundary
|
|
case 'A':
|
|
return ntBeginning
|
|
case 'G':
|
|
return ntStart
|
|
case 'Z':
|
|
return ntEndZ
|
|
case 'z':
|
|
return ntEnd
|
|
default:
|
|
return ntNothing
|
|
}
|
|
}
|
|
|
|
// Scans whitespace or x-mode comments.
|
|
func (p *parser) scanBlank() error {
|
|
if p.useOptionX() {
|
|
for {
|
|
for p.charsRight() > 0 && isSpace(p.rightChar(0)) {
|
|
p.moveRight(1)
|
|
}
|
|
|
|
if p.charsRight() == 0 {
|
|
break
|
|
}
|
|
|
|
if p.rightChar(0) == '#' {
|
|
for p.charsRight() > 0 && p.rightChar(0) != '\n' {
|
|
p.moveRight(1)
|
|
}
|
|
} else if p.charsRight() >= 3 && p.rightChar(2) == '#' &&
|
|
p.rightChar(1) == '?' && p.rightChar(0) == '(' {
|
|
for p.charsRight() > 0 && p.rightChar(0) != ')' {
|
|
p.moveRight(1)
|
|
}
|
|
if p.charsRight() == 0 {
|
|
return p.getErr(ErrUnterminatedComment)
|
|
}
|
|
p.moveRight(1)
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
} else {
|
|
for {
|
|
if p.charsRight() < 3 || p.rightChar(2) != '#' ||
|
|
p.rightChar(1) != '?' || p.rightChar(0) != '(' {
|
|
return nil
|
|
}
|
|
|
|
for p.charsRight() > 0 && p.rightChar(0) != ')' {
|
|
p.moveRight(1)
|
|
}
|
|
if p.charsRight() == 0 {
|
|
return p.getErr(ErrUnterminatedComment)
|
|
}
|
|
p.moveRight(1)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (p *parser) scanCapname() string {
|
|
startpos := p.textpos()
|
|
|
|
for p.charsRight() > 0 {
|
|
if !IsWordChar(p.moveRightGetChar()) {
|
|
p.moveLeft()
|
|
break
|
|
}
|
|
}
|
|
|
|
return string(p.pattern[startpos:p.textpos()])
|
|
}
|
|
|
|
//Scans contents of [] (not including []'s), and converts to a set.
|
|
func (p *parser) scanCharSet(caseInsensitive, scanOnly bool) (*CharSet, error) {
|
|
ch := '\x00'
|
|
chPrev := '\x00'
|
|
inRange := false
|
|
firstChar := true
|
|
closed := false
|
|
|
|
var cc *CharSet
|
|
if !scanOnly {
|
|
cc = &CharSet{}
|
|
}
|
|
|
|
if p.charsRight() > 0 && p.rightChar(0) == '^' {
|
|
p.moveRight(1)
|
|
if !scanOnly {
|
|
cc.negate = true
|
|
}
|
|
}
|
|
|
|
for ; p.charsRight() > 0; firstChar = false {
|
|
fTranslatedChar := false
|
|
ch = p.moveRightGetChar()
|
|
if ch == ']' {
|
|
if !firstChar {
|
|
closed = true
|
|
break
|
|
} else if p.useOptionE() {
|
|
if !scanOnly {
|
|
cc.addRanges(NoneClass().ranges)
|
|
}
|
|
closed = true
|
|
break
|
|
}
|
|
|
|
} else if ch == '\\' && p.charsRight() > 0 {
|
|
switch ch = p.moveRightGetChar(); ch {
|
|
case 'D', 'd':
|
|
if !scanOnly {
|
|
if inRange {
|
|
return nil, p.getErr(ErrBadClassInCharRange, ch)
|
|
}
|
|
cc.addDigit(p.useOptionE(), ch == 'D', p.patternRaw)
|
|
}
|
|
continue
|
|
|
|
case 'S', 's':
|
|
if !scanOnly {
|
|
if inRange {
|
|
return nil, p.getErr(ErrBadClassInCharRange, ch)
|
|
}
|
|
cc.addSpace(p.useOptionE(), ch == 'S')
|
|
}
|
|
continue
|
|
|
|
case 'W', 'w':
|
|
if !scanOnly {
|
|
if inRange {
|
|
return nil, p.getErr(ErrBadClassInCharRange, ch)
|
|
}
|
|
|
|
cc.addWord(p.useOptionE(), ch == 'W')
|
|
}
|
|
continue
|
|
|
|
case 'p', 'P':
|
|
if !scanOnly {
|
|
if inRange {
|
|
return nil, p.getErr(ErrBadClassInCharRange, ch)
|
|
}
|
|
prop, err := p.parseProperty()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cc.addCategory(prop, (ch != 'p'), caseInsensitive, p.patternRaw)
|
|
} else {
|
|
p.parseProperty()
|
|
}
|
|
|
|
continue
|
|
|
|
case '-':
|
|
if !scanOnly {
|
|
cc.addRange(ch, ch)
|
|
}
|
|
continue
|
|
|
|
default:
|
|
p.moveLeft()
|
|
var err error
|
|
ch, err = p.scanCharEscape() // non-literal character
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
fTranslatedChar = true
|
|
break // this break will only break out of the switch
|
|
}
|
|
} else if ch == '[' {
|
|
// This is code for Posix style properties - [:Ll:] or [:IsTibetan:].
|
|
// It currently doesn't do anything other than skip the whole thing!
|
|
if p.charsRight() > 0 && p.rightChar(0) == ':' && !inRange {
|
|
savePos := p.textpos()
|
|
|
|
p.moveRight(1)
|
|
negate := false
|
|
if p.charsRight() > 1 && p.rightChar(0) == '^' {
|
|
negate = true
|
|
p.moveRight(1)
|
|
}
|
|
|
|
nm := p.scanCapname() // snag the name
|
|
if !scanOnly && p.useRE2() {
|
|
// look up the name since these are valid for RE2
|
|
// add the group based on the name
|
|
if ok := cc.addNamedASCII(nm, negate); !ok {
|
|
return nil, p.getErr(ErrInvalidCharRange)
|
|
}
|
|
}
|
|
if p.charsRight() < 2 || p.moveRightGetChar() != ':' || p.moveRightGetChar() != ']' {
|
|
p.textto(savePos)
|
|
} else if p.useRE2() {
|
|
// move on
|
|
continue
|
|
}
|
|
}
|
|
}
|
|
|
|
if inRange {
|
|
inRange = false
|
|
if !scanOnly {
|
|
if ch == '[' && !fTranslatedChar && !firstChar {
|
|
// We thought we were in a range, but we're actually starting a subtraction.
|
|
// In that case, we'll add chPrev to our char class, skip the opening [, and
|
|
// scan the new character class recursively.
|
|
cc.addChar(chPrev)
|
|
sub, err := p.scanCharSet(caseInsensitive, false)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cc.addSubtraction(sub)
|
|
|
|
if p.charsRight() > 0 && p.rightChar(0) != ']' {
|
|
return nil, p.getErr(ErrSubtractionMustBeLast)
|
|
}
|
|
} else {
|
|
// a regular range, like a-z
|
|
if chPrev > ch {
|
|
return nil, p.getErr(ErrReversedCharRange)
|
|
}
|
|
cc.addRange(chPrev, ch)
|
|
}
|
|
}
|
|
} else if p.charsRight() >= 2 && p.rightChar(0) == '-' && p.rightChar(1) != ']' {
|
|
// this could be the start of a range
|
|
chPrev = ch
|
|
inRange = true
|
|
p.moveRight(1)
|
|
} else if p.charsRight() >= 1 && ch == '-' && !fTranslatedChar && p.rightChar(0) == '[' && !firstChar {
|
|
// we aren't in a range, and now there is a subtraction. Usually this happens
|
|
// only when a subtraction follows a range, like [a-z-[b]]
|
|
if !scanOnly {
|
|
p.moveRight(1)
|
|
sub, err := p.scanCharSet(caseInsensitive, false)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cc.addSubtraction(sub)
|
|
|
|
if p.charsRight() > 0 && p.rightChar(0) != ']' {
|
|
return nil, p.getErr(ErrSubtractionMustBeLast)
|
|
}
|
|
} else {
|
|
p.moveRight(1)
|
|
p.scanCharSet(caseInsensitive, true)
|
|
}
|
|
} else {
|
|
if !scanOnly {
|
|
cc.addRange(ch, ch)
|
|
}
|
|
}
|
|
}
|
|
|
|
if !closed {
|
|
return nil, p.getErr(ErrUnterminatedBracket)
|
|
}
|
|
|
|
if !scanOnly && caseInsensitive {
|
|
cc.addLowercase()
|
|
}
|
|
|
|
return cc, nil
|
|
}
|
|
|
|
// Scans any number of decimal digits (pegs value at 2^31-1 if too large)
|
|
func (p *parser) scanDecimal() (int, error) {
|
|
i := 0
|
|
var d int
|
|
|
|
for p.charsRight() > 0 {
|
|
d = int(p.rightChar(0) - '0')
|
|
if d < 0 || d > 9 {
|
|
break
|
|
}
|
|
p.moveRight(1)
|
|
|
|
if i > maxValueDiv10 || (i == maxValueDiv10 && d > maxValueMod10) {
|
|
return 0, p.getErr(ErrCaptureGroupOutOfRange)
|
|
}
|
|
|
|
i *= 10
|
|
i += d
|
|
}
|
|
|
|
return int(i), nil
|
|
}
|
|
|
|
// Returns true for options allowed only at the top level
|
|
func isOnlyTopOption(option RegexOptions) bool {
|
|
return option == RightToLeft || option == ECMAScript || option == RE2
|
|
}
|
|
|
|
// Scans cimsx-cimsx option string, stops at the first unrecognized char.
|
|
func (p *parser) scanOptions() {
|
|
|
|
for off := false; p.charsRight() > 0; p.moveRight(1) {
|
|
ch := p.rightChar(0)
|
|
|
|
if ch == '-' {
|
|
off = true
|
|
} else if ch == '+' {
|
|
off = false
|
|
} else {
|
|
option := optionFromCode(ch)
|
|
if option == 0 || isOnlyTopOption(option) {
|
|
return
|
|
}
|
|
|
|
if off {
|
|
p.options &= ^option
|
|
} else {
|
|
p.options |= option
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Scans \ code for escape codes that map to single unicode chars.
|
|
func (p *parser) scanCharEscape() (r rune, err error) {
|
|
|
|
ch := p.moveRightGetChar()
|
|
|
|
if ch >= '0' && ch <= '7' {
|
|
p.moveLeft()
|
|
return p.scanOctal(), nil
|
|
}
|
|
|
|
pos := p.textpos()
|
|
|
|
switch ch {
|
|
case 'x':
|
|
// support for \x{HEX} syntax from Perl and PCRE
|
|
if p.charsRight() > 0 && p.rightChar(0) == '{' {
|
|
if p.useOptionE() {
|
|
return ch, nil
|
|
}
|
|
p.moveRight(1)
|
|
return p.scanHexUntilBrace()
|
|
} else {
|
|
r, err = p.scanHex(2)
|
|
}
|
|
case 'u':
|
|
r, err = p.scanHex(4)
|
|
case 'a':
|
|
return '\u0007', nil
|
|
case 'b':
|
|
return '\b', nil
|
|
case 'e':
|
|
return '\u001B', nil
|
|
case 'f':
|
|
return '\f', nil
|
|
case 'n':
|
|
return '\n', nil
|
|
case 'r':
|
|
return '\r', nil
|
|
case 't':
|
|
return '\t', nil
|
|
case 'v':
|
|
return '\u000B', nil
|
|
case 'c':
|
|
r, err = p.scanControl()
|
|
default:
|
|
if !p.useOptionE() && IsWordChar(ch) {
|
|
return 0, p.getErr(ErrUnrecognizedEscape, string(ch))
|
|
}
|
|
return ch, nil
|
|
}
|
|
if err != nil && p.useOptionE() {
|
|
p.textto(pos)
|
|
return ch, nil
|
|
}
|
|
return
|
|
}
|
|
|
|
// Grabs and converts an ascii control character
|
|
func (p *parser) scanControl() (rune, error) {
|
|
if p.charsRight() <= 0 {
|
|
return 0, p.getErr(ErrMissingControl)
|
|
}
|
|
|
|
ch := p.moveRightGetChar()
|
|
|
|
// \ca interpreted as \cA
|
|
|
|
if ch >= 'a' && ch <= 'z' {
|
|
ch = (ch - ('a' - 'A'))
|
|
}
|
|
ch = (ch - '@')
|
|
if ch >= 0 && ch < ' ' {
|
|
return ch, nil
|
|
}
|
|
|
|
return 0, p.getErr(ErrUnrecognizedControl)
|
|
|
|
}
|
|
|
|
// Scan hex digits until we hit a closing brace.
|
|
// Non-hex digits, hex value too large for UTF-8, or running out of chars are errors
|
|
func (p *parser) scanHexUntilBrace() (rune, error) {
|
|
// PCRE spec reads like unlimited hex digits are allowed, but unicode has a limit
|
|
// so we can enforce that
|
|
i := 0
|
|
hasContent := false
|
|
|
|
for p.charsRight() > 0 {
|
|
ch := p.moveRightGetChar()
|
|
if ch == '}' {
|
|
// hit our close brace, we're done here
|
|
// prevent \x{}
|
|
if !hasContent {
|
|
return 0, p.getErr(ErrTooFewHex)
|
|
}
|
|
return rune(i), nil
|
|
}
|
|
hasContent = true
|
|
// no brace needs to be hex digit
|
|
d := hexDigit(ch)
|
|
if d < 0 {
|
|
return 0, p.getErr(ErrMissingBrace)
|
|
}
|
|
|
|
i *= 0x10
|
|
i += d
|
|
|
|
if i > unicode.MaxRune {
|
|
return 0, p.getErr(ErrInvalidHex)
|
|
}
|
|
}
|
|
|
|
// we only make it here if we run out of digits without finding the brace
|
|
return 0, p.getErr(ErrMissingBrace)
|
|
}
|
|
|
|
// Scans exactly c hex digits (c=2 for \xFF, c=4 for \uFFFF)
|
|
func (p *parser) scanHex(c int) (rune, error) {
|
|
|
|
i := 0
|
|
|
|
if p.charsRight() >= c {
|
|
for c > 0 {
|
|
d := hexDigit(p.moveRightGetChar())
|
|
if d < 0 {
|
|
break
|
|
}
|
|
i *= 0x10
|
|
i += d
|
|
c--
|
|
}
|
|
}
|
|
|
|
if c > 0 {
|
|
return 0, p.getErr(ErrTooFewHex)
|
|
}
|
|
|
|
return rune(i), nil
|
|
}
|
|
|
|
// Returns n <= 0xF for a hex digit.
|
|
func hexDigit(ch rune) int {
|
|
|
|
if d := uint(ch - '0'); d <= 9 {
|
|
return int(d)
|
|
}
|
|
|
|
if d := uint(ch - 'a'); d <= 5 {
|
|
return int(d + 0xa)
|
|
}
|
|
|
|
if d := uint(ch - 'A'); d <= 5 {
|
|
return int(d + 0xa)
|
|
}
|
|
|
|
return -1
|
|
}
|
|
|
|
// Scans up to three octal digits (stops before exceeding 0377).
|
|
func (p *parser) scanOctal() rune {
|
|
// Consume octal chars only up to 3 digits and value 0377
|
|
|
|
c := 3
|
|
|
|
if c > p.charsRight() {
|
|
c = p.charsRight()
|
|
}
|
|
|
|
//we know the first char is good because the caller had to check
|
|
i := 0
|
|
d := int(p.rightChar(0) - '0')
|
|
for c > 0 && d <= 7 && d >= 0 {
|
|
if i >= 0x20 && p.useOptionE() {
|
|
break
|
|
}
|
|
i *= 8
|
|
i += d
|
|
c--
|
|
|
|
p.moveRight(1)
|
|
if !p.rightMost() {
|
|
d = int(p.rightChar(0) - '0')
|
|
}
|
|
}
|
|
|
|
// Octal codes only go up to 255. Any larger and the behavior that Perl follows
|
|
// is simply to truncate the high bits.
|
|
i &= 0xFF
|
|
|
|
return rune(i)
|
|
}
|
|
|
|
// Returns the current parsing position.
|
|
func (p *parser) textpos() int {
|
|
return p.currentPos
|
|
}
|
|
|
|
// Zaps to a specific parsing position.
|
|
func (p *parser) textto(pos int) {
|
|
p.currentPos = pos
|
|
}
|
|
|
|
// Returns the char at the right of the current parsing position and advances to the right.
|
|
func (p *parser) moveRightGetChar() rune {
|
|
ch := p.pattern[p.currentPos]
|
|
p.currentPos++
|
|
return ch
|
|
}
|
|
|
|
// Moves the current position to the right.
|
|
func (p *parser) moveRight(i int) {
|
|
// default would be 1
|
|
p.currentPos += i
|
|
}
|
|
|
|
// Moves the current parsing position one to the left.
|
|
func (p *parser) moveLeft() {
|
|
p.currentPos--
|
|
}
|
|
|
|
// Returns the char left of the current parsing position.
|
|
func (p *parser) charAt(i int) rune {
|
|
return p.pattern[i]
|
|
}
|
|
|
|
// Returns the char i chars right of the current parsing position.
|
|
func (p *parser) rightChar(i int) rune {
|
|
// default would be 0
|
|
return p.pattern[p.currentPos+i]
|
|
}
|
|
|
|
// Number of characters to the right of the current parsing position.
|
|
func (p *parser) charsRight() int {
|
|
return len(p.pattern) - p.currentPos
|
|
}
|
|
|
|
func (p *parser) rightMost() bool {
|
|
return p.currentPos == len(p.pattern)
|
|
}
|
|
|
|
// Looks up the slot number for a given name
|
|
func (p *parser) captureSlotFromName(capname string) int {
|
|
return p.capnames[capname]
|
|
}
|
|
|
|
// True if the capture slot was noted
|
|
func (p *parser) isCaptureSlot(i int) bool {
|
|
if p.caps != nil {
|
|
_, ok := p.caps[i]
|
|
return ok
|
|
}
|
|
|
|
return (i >= 0 && i < p.capsize)
|
|
}
|
|
|
|
// Looks up the slot number for a given name
|
|
func (p *parser) isCaptureName(capname string) bool {
|
|
if p.capnames == nil {
|
|
return false
|
|
}
|
|
|
|
_, ok := p.capnames[capname]
|
|
return ok
|
|
}
|
|
|
|
// option shortcuts
|
|
|
|
// True if N option disabling '(' autocapture is on.
|
|
func (p *parser) useOptionN() bool {
|
|
return (p.options & ExplicitCapture) != 0
|
|
}
|
|
|
|
// True if I option enabling case-insensitivity is on.
|
|
func (p *parser) useOptionI() bool {
|
|
return (p.options & IgnoreCase) != 0
|
|
}
|
|
|
|
// True if M option altering meaning of $ and ^ is on.
|
|
func (p *parser) useOptionM() bool {
|
|
return (p.options & Multiline) != 0
|
|
}
|
|
|
|
// True if S option altering meaning of . is on.
|
|
func (p *parser) useOptionS() bool {
|
|
return (p.options & Singleline) != 0
|
|
}
|
|
|
|
// True if X option enabling whitespace/comment mode is on.
|
|
func (p *parser) useOptionX() bool {
|
|
return (p.options & IgnorePatternWhitespace) != 0
|
|
}
|
|
|
|
// True if E option enabling ECMAScript behavior on.
|
|
func (p *parser) useOptionE() bool {
|
|
return (p.options & ECMAScript) != 0
|
|
}
|
|
|
|
// true to use RE2 compatibility parsing behavior.
|
|
func (p *parser) useRE2() bool {
|
|
return (p.options & RE2) != 0
|
|
}
|
|
|
|
// True if options stack is empty.
|
|
func (p *parser) emptyOptionsStack() bool {
|
|
return len(p.optionsStack) == 0
|
|
}
|
|
|
|
// Finish the current quantifiable (when a quantifier is not found or is not possible)
|
|
func (p *parser) addConcatenate() {
|
|
// The first (| inside a Testgroup group goes directly to the group
|
|
p.concatenation.addChild(p.unit)
|
|
p.unit = nil
|
|
}
|
|
|
|
// Finish the current quantifiable (when a quantifier is found)
|
|
func (p *parser) addConcatenate3(lazy bool, min, max int) {
|
|
p.concatenation.addChild(p.unit.makeQuantifier(lazy, min, max))
|
|
p.unit = nil
|
|
}
|
|
|
|
// Sets the current unit to a single char node
|
|
func (p *parser) addUnitOne(ch rune) {
|
|
if p.useOptionI() {
|
|
ch = unicode.ToLower(ch)
|
|
}
|
|
|
|
p.unit = newRegexNodeCh(ntOne, p.options, ch)
|
|
}
|
|
|
|
// Sets the current unit to a single inverse-char node
|
|
func (p *parser) addUnitNotone(ch rune) {
|
|
if p.useOptionI() {
|
|
ch = unicode.ToLower(ch)
|
|
}
|
|
|
|
p.unit = newRegexNodeCh(ntNotone, p.options, ch)
|
|
}
|
|
|
|
// Sets the current unit to a single set node
|
|
func (p *parser) addUnitSet(set *CharSet) {
|
|
p.unit = newRegexNodeSet(ntSet, p.options, set)
|
|
}
|
|
|
|
// Sets the current unit to a subtree
|
|
func (p *parser) addUnitNode(node *regexNode) {
|
|
p.unit = node
|
|
}
|
|
|
|
// Sets the current unit to an assertion of the specified type
|
|
func (p *parser) addUnitType(t nodeType) {
|
|
p.unit = newRegexNode(t, p.options)
|
|
}
|
|
|
|
// Finish the current group (in response to a ')' or end)
|
|
func (p *parser) addGroup() error {
|
|
if p.group.t == ntTestgroup || p.group.t == ntTestref {
|
|
p.group.addChild(p.concatenation.reverseLeft())
|
|
if (p.group.t == ntTestref && len(p.group.children) > 2) || len(p.group.children) > 3 {
|
|
return p.getErr(ErrTooManyAlternates)
|
|
}
|
|
} else {
|
|
p.alternation.addChild(p.concatenation.reverseLeft())
|
|
p.group.addChild(p.alternation)
|
|
}
|
|
|
|
p.unit = p.group
|
|
return nil
|
|
}
|
|
|
|
// Pops the option stack, but keeps the current options unchanged.
|
|
func (p *parser) popKeepOptions() {
|
|
lastIdx := len(p.optionsStack) - 1
|
|
p.optionsStack = p.optionsStack[:lastIdx]
|
|
}
|
|
|
|
// Recalls options from the stack.
|
|
func (p *parser) popOptions() {
|
|
lastIdx := len(p.optionsStack) - 1
|
|
// get the last item on the stack and then remove it by reslicing
|
|
p.options = p.optionsStack[lastIdx]
|
|
p.optionsStack = p.optionsStack[:lastIdx]
|
|
}
|
|
|
|
// Saves options on a stack.
|
|
func (p *parser) pushOptions() {
|
|
p.optionsStack = append(p.optionsStack, p.options)
|
|
}
|
|
|
|
// Add a string to the last concatenate.
|
|
func (p *parser) addToConcatenate(pos, cch int, isReplacement bool) {
|
|
var node *regexNode
|
|
|
|
if cch == 0 {
|
|
return
|
|
}
|
|
|
|
if cch > 1 {
|
|
str := p.pattern[pos : pos+cch]
|
|
|
|
if p.useOptionI() && !isReplacement {
|
|
// We do the ToLower character by character for consistency. With surrogate chars, doing
|
|
// a ToLower on the entire string could actually change the surrogate pair. This is more correct
|
|
// linguistically, but since Regex doesn't support surrogates, it's more important to be
|
|
// consistent.
|
|
for i := 0; i < len(str); i++ {
|
|
str[i] = unicode.ToLower(str[i])
|
|
}
|
|
}
|
|
|
|
node = newRegexNodeStr(ntMulti, p.options, str)
|
|
} else {
|
|
ch := p.charAt(pos)
|
|
|
|
if p.useOptionI() && !isReplacement {
|
|
ch = unicode.ToLower(ch)
|
|
}
|
|
|
|
node = newRegexNodeCh(ntOne, p.options, ch)
|
|
}
|
|
|
|
p.concatenation.addChild(node)
|
|
}
|
|
|
|
// Push the parser state (in response to an open paren)
|
|
func (p *parser) pushGroup() {
|
|
p.group.next = p.stack
|
|
p.alternation.next = p.group
|
|
p.concatenation.next = p.alternation
|
|
p.stack = p.concatenation
|
|
}
|
|
|
|
// Remember the pushed state (in response to a ')')
|
|
func (p *parser) popGroup() error {
|
|
p.concatenation = p.stack
|
|
p.alternation = p.concatenation.next
|
|
p.group = p.alternation.next
|
|
p.stack = p.group.next
|
|
|
|
// The first () inside a Testgroup group goes directly to the group
|
|
if p.group.t == ntTestgroup && len(p.group.children) == 0 {
|
|
if p.unit == nil {
|
|
return p.getErr(ErrConditionalExpression)
|
|
}
|
|
|
|
p.group.addChild(p.unit)
|
|
p.unit = nil
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// True if the group stack is empty.
|
|
func (p *parser) emptyStack() bool {
|
|
return p.stack == nil
|
|
}
|
|
|
|
// Start a new round for the parser state (in response to an open paren or string start)
|
|
func (p *parser) startGroup(openGroup *regexNode) {
|
|
p.group = openGroup
|
|
p.alternation = newRegexNode(ntAlternate, p.options)
|
|
p.concatenation = newRegexNode(ntConcatenate, p.options)
|
|
}
|
|
|
|
// Finish the current concatenation (in response to a |)
|
|
func (p *parser) addAlternate() {
|
|
// The | parts inside a Testgroup group go directly to the group
|
|
|
|
if p.group.t == ntTestgroup || p.group.t == ntTestref {
|
|
p.group.addChild(p.concatenation.reverseLeft())
|
|
} else {
|
|
p.alternation.addChild(p.concatenation.reverseLeft())
|
|
}
|
|
|
|
p.concatenation = newRegexNode(ntConcatenate, p.options)
|
|
}
|
|
|
|
// For categorizing ascii characters.
|
|
|
|
const (
|
|
Q byte = 5 // quantifier
|
|
S = 4 // ordinary stopper
|
|
Z = 3 // ScanBlank stopper
|
|
X = 2 // whitespace
|
|
E = 1 // should be escaped
|
|
)
|
|
|
|
var _category = []byte{
|
|
//01 2 3 4 5 6 7 8 9 A B C D E F 0 1 2 3 4 5 6 7 8 9 A B C D E F
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, X, X, X, X, X, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
// ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
|
|
X, 0, 0, Z, S, 0, 0, 0, S, S, Q, Q, 0, 0, S, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, Q,
|
|
//@A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, S, S, 0, S, 0,
|
|
//'a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, Q, S, 0, 0, 0,
|
|
}
|
|
|
|
func isSpace(ch rune) bool {
|
|
return (ch <= ' ' && _category[ch] == X)
|
|
}
|
|
|
|
// Returns true for those characters that terminate a string of ordinary chars.
|
|
func isSpecial(ch rune) bool {
|
|
return (ch <= '|' && _category[ch] >= S)
|
|
}
|
|
|
|
// Returns true for those characters that terminate a string of ordinary chars.
|
|
func isStopperX(ch rune) bool {
|
|
return (ch <= '|' && _category[ch] >= X)
|
|
}
|
|
|
|
// Returns true for those characters that begin a quantifier.
|
|
func isQuantifier(ch rune) bool {
|
|
return (ch <= '{' && _category[ch] >= Q)
|
|
}
|
|
|
|
func (p *parser) isTrueQuantifier() bool {
|
|
nChars := p.charsRight()
|
|
if nChars == 0 {
|
|
return false
|
|
}
|
|
|
|
startpos := p.textpos()
|
|
ch := p.charAt(startpos)
|
|
if ch != '{' {
|
|
return ch <= '{' && _category[ch] >= Q
|
|
}
|
|
|
|
//UGLY: this is ugly -- the original code was ugly too
|
|
pos := startpos
|
|
for {
|
|
nChars--
|
|
if nChars <= 0 {
|
|
break
|
|
}
|
|
pos++
|
|
ch = p.charAt(pos)
|
|
if ch < '0' || ch > '9' {
|
|
break
|
|
}
|
|
}
|
|
|
|
if nChars == 0 || pos-startpos == 1 {
|
|
return false
|
|
}
|
|
if ch == '}' {
|
|
return true
|
|
}
|
|
if ch != ',' {
|
|
return false
|
|
}
|
|
for {
|
|
nChars--
|
|
if nChars <= 0 {
|
|
break
|
|
}
|
|
pos++
|
|
ch = p.charAt(pos)
|
|
if ch < '0' || ch > '9' {
|
|
break
|
|
}
|
|
}
|
|
|
|
return nChars > 0 && ch == '}'
|
|
}
|