/**************************************************************************** ** ** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved. ** ** This file is part of the QtCore module of the Qt Toolkit. ** ** This file may be used under the terms of the GNU General Public ** License version 2.0 as published by the Free Software Foundation ** and appearing in the file LICENSE.GPL included in the packaging of ** this file. Please review the following information to ensure GNU ** General Public Licensing requirements will be met: ** http://trolltech.com/products/qt/licenses/licensing/opensource/ ** ** If you are unsure which license is appropriate for your use, please ** review the following information: ** http://trolltech.com/products/qt/licenses/licensing/licensingoverview ** or contact the sales department at sales@trolltech.com. ** ** In addition, as a special exception, Trolltech gives you certain ** additional rights. These rights are described in the Trolltech GPL ** Exception version 1.0, which can be found at ** http://www.trolltech.com/products/qt/gplexception/ and in the file ** GPL_EXCEPTION.txt in this package. ** ** In addition, as a special exception, Trolltech, as the sole copyright ** holder for Qt Designer, grants users of the Qt/Eclipse Integration ** plug-in the right for the Qt/Eclipse Integration to link to ** functionality provided by Qt Designer and its related libraries. ** ** Trolltech reserves all rights not expressly granted herein. ** ** Trolltech ASA (c) 2007 ** ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ** ****************************************************************************/ #include "qregexp.h" #include "qalgorithms.h" #include "qbitarray.h" #include "qcache.h" #include "qdatastream.h" #include "qlist.h" #include "qmap.h" #include "qmutex.h" #include "qstring.h" #include "qstringlist.h" #include "qvector.h" #include // error strings for the regexp parser #define RXERR_OK QT_TRANSLATE_NOOP("QRegExp", "no error occurred") #define RXERR_DISABLED QT_TRANSLATE_NOOP("QRegExp", "disabled feature used") #define RXERR_CHARCLASS QT_TRANSLATE_NOOP("QRegExp", "bad char class syntax") #define RXERR_LOOKAHEAD QT_TRANSLATE_NOOP("QRegExp", "bad lookahead syntax") #define RXERR_REPETITION QT_TRANSLATE_NOOP("QRegExp", "bad repetition syntax") #define RXERR_OCTAL QT_TRANSLATE_NOOP("QRegExp", "invalid octal value") #define RXERR_LEFTDELIM QT_TRANSLATE_NOOP("QRegExp", "missing left delim") #define RXERR_END QT_TRANSLATE_NOOP("QRegExp", "unexpected end") #define RXERR_LIMIT QT_TRANSLATE_NOOP("QRegExp", "met internal limit") /* WARNING! Be sure to read qregexp.tex before modifying this file. */ /*! \class QRegExp \reentrant \brief The QRegExp class provides pattern matching using regular expressions. \ingroup tools \ingroup misc \ingroup shared \mainclass \keyword regular expression Regular expressions, or "regexps", provide a way to find patterns within text. This is useful in many contexts, for example: \table \row \i Validation \i A regexp can be used to check whether a piece of text meets some criteria, e.g. is an integer or contains no whitespace. \row \i Searching \i Regexps provide a much more powerful means of searching text than simple string matching does. For example we can create a regexp which says "find one of the words 'mail', 'letter' or 'correspondence' but not any of the words 'email', 'mailman' 'mailer', 'letterbox', etc." \row \i Search and Replace \i A regexp can be used to replace a pattern with a piece of text, for example replace all occurrences of '&' with '\&' except where the '&' is already followed by 'amp;'. \row \i String Splitting \i A regexp can be used to identify where a string should be split into its component fields, e.g. splitting tab-delimited strings. \endtable We present a very brief introduction to regexps, a description of Qt's regexp language, some code examples, and finally the function documentation itself. QRegExp is modeled on Perl's regexp language, and also fully supports Unicode. QRegExp can also be used in the weaker wildcard mode that works in a similar way to command shells. It can even be feed with fixed strings (see setPatternSyntax()). A good text on regexps is \e {Mastering Regular Expressions} (Third Edition) by Jeffrey E. F. Friedl, ISBN 0-596-52812-4. \tableofcontents \section1 Introduction Regexps are built up from expressions, quantifiers, and assertions. The simplest form of expression is simply a character, e.g. \bold{x} or \bold{5}. An expression can also be a set of characters. For example, \bold{[ABCD]}, will match an \bold{A} or a \bold{B} or a \bold{C} or a \bold{D}. As a shorthand we could write this as \bold{[A-D]}. If we want to match any of the captital letters in the English alphabet we can write \bold{[A-Z]}. A quantifier tells the regexp engine how many occurrences of the expression we want, e.g. \bold{x{1,1}} means match an \bold{x} which occurs at least once and at most once. We'll look at assertions and more complex expressions later. Note that in general regexps cannot be used to check for balanced brackets or tags. For example if you want to match an opening html \c{} and its closing \c{}, you can only use a regexp if you know that these tags are not nested; the html fragment, \c{bold bolder} will not match as expected. If you know the maximum level of nesting it is possible to create a regexp that will match correctly, but for an unknown level of nesting, regexps will fail. We'll start by writing a regexp to match integers in the range 0 to 99. We will require at least one digit so we will start with \bold{[0-9]{1,1}} which means match a digit exactly once. This regexp alone will match integers in the range 0 to 9. To match one or two digits we can increase the maximum number of occurrences so the regexp becomes \bold{[0-9]{1,2}} meaning match a digit at least once and at most twice. However, this regexp as it stands will not match correctly. This regexp will match one or two digits \e within a string. To ensure that we match against the whole string we must use the anchor assertions. We need \bold{^} (caret) which when it is the first character in the regexp means that the regexp must match from the beginning of the string. And we also need \bold{$} (dollar) which when it is the last character in the regexp means that the regexp must match until the end of the string. So now our regexp is \bold{^[0-9]{1,2}$}. Note that assertions, such as \bold{^} and \bold{$}, do not match any characters. If you've seen regexps elsewhere, they may have looked different from the ones above. This is because some sets of characters and some quantifiers are so common that they have special symbols to represent them. \bold{[0-9]} can be replaced with the symbol \bold{\\d}. The quantifier to match exactly one occurrence, \bold{{1,1}}, can be replaced with the expression itself. This means that \bold{x{1,1}} is exactly the same as \bold{x} alone. So our 0 to 99 matcher could be written \bold{^\\d{1,2}$}. Another way of writing it would be \bold{^\\d\\d{0,1}$}, i.e. from the start of the string match a digit followed by zero or one digits. In practice most people would write it \bold{^\\d\\d?$}. The \bold{?} is a shorthand for the quantifier \bold{{0,1}}, i.e. a minimum of no occurrences a maximum of one occurrence. This is used to make an expression optional. The regexp \bold{^\\d\\d?$} means "from the beginning of the string match one digit followed by zero or one digits and then the end of the string". Our second example is matching the words 'mail', 'letter' or 'correspondence' but without matching 'email', 'mailman', 'mailer', 'letterbox', etc. We'll start by just matching 'mail'. In full the regexp is, \bold{m{1,1}a{1,1}i{1,1}l{1,1}}, but since each expression itself is automatically quantified by \bold{{1,1}} we can simply write this as \bold{mail}; an 'm' followed by an 'a' followed by an 'i' followed by an 'l'. The symbol '|' (bar) is used for \e alternation, so our regexp now becomes \bold{mail|letter|correspondence} which means match 'mail' \e or 'letter' \e or 'correspondence'. Whilst this regexp will find the words we want it will also find words we don't want such as 'email'. We will start by putting our regexp in parentheses, \bold{(mail|letter|correspondence)}. Parentheses have two effects, firstly they group expressions together and secondly they identify parts of the regexp that we wish to \l{capturing text}{capture}. Our regexp still matches any of the three words but now they are grouped together as a unit. This is useful for building up more complex regexps. It is also useful because it allows us to examine which of the words actually matched. We need to use another assertion, this time \bold{\\b} "word boundary": \bold{\\b(mail|letter|correspondence)\\b}. This regexp means "match a word boundary followed by the expression in parentheses followed by another word boundary". The \bold{\\b} assertion matches at a \e position in the regexp not a \e character in the regexp. A word boundary is any non-word character such as a space a newline or the beginning or end of the string. For our third example we want to replace ampersands with the HTML entity '\&'. The regexp to match is simple: \bold{\&}, i.e. match one ampersand. Unfortunately this will mess up our text if some of the ampersands have already been turned into HTML entities. So what we really want to say is replace an ampersand providing it is not followed by 'amp;'. For this we need the negative lookahead assertion and our regexp becomes: \bold{\&(?!amp;)}. The negative lookahead assertion is introduced with '(?!' and finishes at the ')'. It means that the text it contains, 'amp;' in our example, must \e not follow the expression that preceeds it. Regexps provide a rich language that can be used in a variety of ways. For example suppose we want to count all the occurrences of 'Eric' and 'Eirik' in a string. Two valid regexps to match these are \bold{\\b(Eric|Eirik)\\b} and \bold{\\bEi?ri[ck]\\b}. We need the word boundary '\\b' so we don't get 'Ericsson' etc. The second regexp actually matches more than we want, 'Eric', 'Erik', 'Eiric' and 'Eirik'. We will implement some the examples above in the \link #code-examples code examples \endlink section. \target characters-and-abbreviations-for-sets-of-characters \section1 Characters and Abbreviations for Sets of Characters \table \header \i Element \i Meaning \row \i \bold{c} \i Any character represents itself unless it has a special regexp meaning. Thus \bold{c} matches the character \e c. \row \i \bold{\\c} \i A character that follows a backslash matches the character itself except where mentioned below. For example if you wished to match a literal caret at the beginning of a string you would write \bold{\^}. \row \i \bold{\\a} \i This matches the ASCII bell character (BEL, 0x07). \row \i \bold{\\f} \i This matches the ASCII form feed character (FF, 0x0C). \row \i \bold{\\n} \i This matches the ASCII line feed character (LF, 0x0A, Unix newline). \row \i \bold{\\r} \i This matches the ASCII carriage return character (CR, 0x0D). \row \i \bold{\\t} \i This matches the ASCII horizontal tab character (HT, 0x09). \row \i \bold{\\v} \i This matches the ASCII vertical tab character (VT, 0x0B). \row \i \bold{\\x\e{hhhh}} \i This matches the Unicode character corresponding to the hexadecimal number \e{hhhh} (between 0x0000 and 0xFFFF). \row \i \bold{\\0\e{ooo}} (i.e., \\zero \e{ooo}) \i matches the ASCII/Latin1 character corresponding to the octal number \e{ooo} (between 0 and 0377). \row \i \bold{. (dot)} \i This matches any character (including newline). \row \i \bold{\\d} \i This matches a digit (QChar::isDigit()). \row \i \bold{\\D} \i This matches a non-digit. \row \i \bold{\\s} \i This matches a whitespace (QChar::isSpace()). \row \i \bold{\\S} \i This matches a non-whitespace. \row \i \bold{\\w} \i This matches a word character (QChar::isLetterOrNumber(), QChar::isMark(), or '_'). \row \i \bold{\\W} \i This matches a non-word character. \row \i \bold{\\\e{n}} \i The \e{n}-th \l backreference, e.g. \\1, \\2, etc. \endtable \bold{Note:} The C++ compiler transforms backslashes in strings, so to include a \bold{\\} in a regexp, you will need to enter it twice, i.e. \c{\\}. To match the backslash character itself, you will need four: \c{\\\\}. \target sets-of-characters \section1 Sets of Characters Square brackets are used to match any character in the set of characters contained within the square brackets. All the character set abbreviations described above can be used within square brackets. Apart from the character set abbreviations and the following two exceptions no characters have special meanings in square brackets. \table \row \i \bold{^} \i The caret negates the character set if it occurs as the first character, i.e. immediately after the opening square bracket. For example, \bold{[abc]} matches 'a' or 'b' or 'c', but \bold{[^abc]} matches anything \e except 'a' or 'b' or 'c'. \row \i \bold{-} \i The dash is used to indicate a range of characters, for example \bold{[W-Z]} matches 'W' or 'X' or 'Y' or 'Z'. \endtable Using the predefined character set abbreviations is more portable than using character ranges across platforms and languages. For example, \bold{[0-9]} matches a digit in Western alphabets but \bold{\\d} matches a digit in \e any alphabet. Note that in most regexp literature sets of characters are called "character classes". \target quantifiers \section1 Quantifiers By default an expression is automatically quantified by \bold{{1,1}}, i.e. it should occur exactly once. In the following list \bold{\e {E}} stands for any expression. An expression is a character or an abbreviation for a set of characters or a set of characters in square brackets or any parenthesised expression. \table \row \i \bold{\e {E}?} \i Matches zero or one occurrence of \e E. This quantifier means "the previous expression is optional" since it will match whether or not the expression occurs in the string. It is the same as \bold{\e {E}{0,1}}. For example \bold{dents?} will match 'dent' and 'dents'. \row \i \bold{\e {E}+} \i Matches one or more occurrences of \e E. This is the same as \bold{\e {E}{1,}}. For example, \bold{0+} will match '0', '00', '000', etc. \row \i \bold{\e {E}*} \i Matches zero or more occurrences of \e E. This is the same as \bold{\e {E}{0,}}. The \bold{*} quantifier is often used by a mistake. Since it matches \e zero or more occurrences it will match no occurrences at all. For example if we want to match strings that end in whitespace and use the regexp \bold{\\s*$} we would get a match on every string. This is because we have said find zero or more whitespace followed by the end of string, so even strings that don't end in whitespace will match. The regexp we want in this case is \bold{\\s+$} to match strings that have at least one whitespace at the end. \row \i \bold{\e {E}{n}} \i Matches exactly \e n occurrences of the expression. This is the same as repeating the expression \e n times. For example, \bold{x{5}} is the same as \bold{xxxxx}. It is also the same as \bold{\e {E}{n,n}}, e.g. \bold{x{5,5}}. \row \i \bold{\e {E}{n,}} \i Matches at least \e n occurrences of the expression. \row \i \bold{\e {E}{,m}} \i Matches at most \e m occurrences of the expression. This is the same as \bold{\e {E}{0,m}}. \row \i \bold{\e {E}{n,m}} \i Matches at least \e n occurrences of the expression and at most \e m occurrences of the expression. \endtable If we wish to apply a quantifier to more than just the preceding character we can use parentheses to group characters together in an expression. For example, \bold{tag+} matches a 't' followed by an 'a' followed by at least one 'g', whereas \bold{(tag)+} matches at least one occurrence of 'tag'. Note that quantifiers are "greedy". They will match as much text as they can. For example, \bold{0+} will match as many zeros as it can from the first zero it finds, e.g. '2.\underline{000}5'. Quantifiers can be made non-greedy, see setMinimal(). \target capturing parentheses \target backreferences \section1 Capturing Text Parentheses allow us to group elements together so that we can quantify and capture them. For example if we have the expression \bold{mail|letter|correspondence} that matches a string we know that \e one of the words matched but not which one. Using parentheses allows us to "capture" whatever is matched within their bounds, so if we used \bold{(mail|letter|correspondence)} and matched this regexp against the string "I sent you some email" we can use the cap() or capturedTexts() functions to extract the matched characters, in this case 'mail'. We can use captured text within the regexp itself. To refer to the captured text we use \e backreferences which are indexed from 1, the same as for cap(). For example we could search for duplicate words in a string using \bold{\\b(\\w+)\\W+\\1\\b} which means match a word boundary followed by one or more word characters followed by one or more non-word characters followed by the same text as the first parenthesized expression followed by a word boundary. If we want to use parentheses purely for grouping and not for capturing we can use the non-capturing syntax, e.g. \bold{(?:green|blue)}. Non-capturing parentheses begin '(?:' and end ')'. In this example we match either 'green' or 'blue' but we do not capture the match so we only know whether or not we matched but not which color we actually found. Using non-capturing parentheses is more efficient than using capturing parentheses since the regexp engine has to do less book-keeping. Both capturing and non-capturing parentheses may be nested. \target greedy quantifiers For historical reasons, quantifiers (e.g. \bold{*}) that apply to capturing parentheses are more "greedy" than other quantifiers. For example, \bold{a*(a)*} will match "aaa" with cap(1) == "aaa". This behavior is different from what other regexp engines do (notably, Perl). To obtain a more intuitive capturing behavior, specify QRegExp::RegExp2 to the QRegExp constructor or call setPatternSyntax(QRegExp::RegExp2). \target cap_in_a_loop When the number of matches cannot be determined in advance, a common idiom is to use cap() in a loop. For example: \code QRegExp rx("(\\d+)"); QString str = "Offsets: 12 14 99 231 7"; QStringList list; int pos = 0; while ((pos = rx.indexIn(str, pos)) != -1) { list << rx.cap(1); pos += rx.matchedLength(); } // list: ["12", "14", "99", "231", "7"] \endcode \target assertions \section1 Assertions Assertions make some statement about the text at the point where they occur in the regexp but they do not match any characters. In the following list \bold{\e {E}} stands for any expression. \table \row \i \bold{^} \i The caret signifies the beginning of the string. If you wish to match a literal \c{^} you must escape it by writing \c{\\^}. For example, \bold{^#include} will only match strings which \e begin with the characters '#include'. (When the caret is the first character of a character set it has a special meaning, see \link #sets-of-characters Sets of Characters \endlink.) \row \i \bold{$} \i The dollar signifies the end of the string. For example \bold{\\d\\s*$} will match strings which end with a digit optionally followed by whitespace. If you wish to match a literal \c{$} you must escape it by writing \c{\\$}. \row \i \bold{\\b} \i A word boundary. For example the regexp \bold{\\bOK\\b} means match immediately after a word boundary (e.g. start of string or whitespace) the letter 'O' then the letter 'K' immediately before another word boundary (e.g. end of string or whitespace). But note that the assertion does not actually match any whitespace so if we write \bold{(\\bOK\\b)} and we have a match it will only contain 'OK' even if the string is "It's \underline{OK} now". \row \i \bold{\\B} \i A non-word boundary. This assertion is true wherever \bold{\\b} is false. For example if we searched for \bold{\\Bon\\B} in "Left on" the match would fail (space and end of string aren't non-word boundaries), but it would match in "t\underline{on}ne". \row \i \bold{(?=\e E)} \i Positive lookahead. This assertion is true if the expression matches at this point in the regexp. For example, \bold{const(?=\\s+char)} matches 'const' whenever it is followed by 'char', as in 'static \underline{const} char *'. (Compare with \bold{const\\s+char}, which matches 'static \underline{const char} *'.) \row \i \bold{(?!\e E)} \i Negative lookahead. This assertion is true if the expression does not match at this point in the regexp. For example, \bold{const(?!\\s+char)} matches 'const' \e except when it is followed by 'char'. \endtable \keyword QRegExp wildcard matching \section1 Wildcard Matching Most command shells such as \e bash or \e cmd.exe support "file globbing", the ability to identify a group of files by using wildcards. The setPatternSyntax() function is used to switch between regexp and wildcard mode. Wildcard matching is much simpler than full regexps and has only four features: \table \row \i \bold{c} \i Any character represents itself apart from those mentioned below. Thus \bold{c} matches the character \e c. \row \i \bold{?} \i This matches any single character. It is the same as \bold{.} in full regexps. \row \i \bold{*} \i This matches zero or more of any characters. It is the same as \bold{.*} in full regexps. \row \i \bold{[...]} \i Sets of characters can be represented in square brackets, similar to full regexps. Within the character class, like outside, backslash has no special meaning. \endtable For example if we are in wildcard mode and have strings which contain filenames we could identify HTML files with \bold{*.html}. This will match zero or more characters followed by a dot followed by 'h', 't', 'm' and 'l'. To test a string against a wildcard expression, use exactMatch(). For example: \code QRegExp rx("*.txt"); rx.setPatternSyntax(QRegExp::Wildcard); rx.exactMatch("README.txt"); // returns true rx.exactMatch("welcome.txt.bak"); // returns false \endcode \target perl-users \section1 Notes for Perl Users Most of the character class abbreviations supported by Perl are supported by QRegExp, see \link #characters-and-abbreviations-for-sets-of-characters characters and abbreviations for sets of characters \endlink. In QRegExp, apart from within character classes, \c{^} always signifies the start of the string, so carets must always be escaped unless used for that purpose. In Perl the meaning of caret varies automagically depending on where it occurs so escaping it is rarely necessary. The same applies to \c{$} which in QRegExp always signifies the end of the string. QRegExp's quantifiers are the same as Perl's greedy quantifiers (but see the \l{greedy quantifiers}{note above}). Non-greedy matching cannot be applied to individual quantifiers, but can be applied to all the quantifiers in the pattern. For example, to match the Perl regexp \bold{ro+?m} requires: \code QRegExp rx("ro+m"); rx.setMinimal(true); \endcode The equivalent of Perl's \c{/i} option is setCaseSensitivity(Qt::CaseInsensitive). Perl's \c{/g} option can be emulated using a \l{#cap_in_a_loop}{loop}. In QRegExp \bold{.} matches any character, therefore all QRegExp regexps have the equivalent of Perl's \c{/s} option. QRegExp does not have an equivalent to Perl's \c{/m} option, but this can be emulated in various ways for example by splitting the input into lines or by looping with a regexp that searches for newlines. Because QRegExp is string oriented, there are no \\A, \\Z, or \\z assertions. The \\G assertion is not supported but can be emulated in a loop. Perl's $& is cap(0) or capturedTexts()[0]. There are no QRegExp equivalents for $`, $' or $+. Perl's capturing variables, $1, $2, ... correspond to cap(1) or capturedTexts()[1], cap(2) or capturedTexts()[2], etc. To substitute a pattern use QString::replace(). Perl's extended \c{/x} syntax is not supported, nor are directives, e.g. (?i), or regexp comments, e.g. (?#comment). On the other hand, C++'s rules for literal strings can be used to achieve the same: \code QRegExp mark("\\b" // word boundary "[Mm]ark" // the word we want to match ); \endcode Both zero-width positive and zero-width negative lookahead assertions (?=pattern) and (?!pattern) are supported with the same syntax as Perl. Perl's lookbehind assertions, "independent" subexpressions and conditional expressions are not supported. Non-capturing parentheses are also supported, with the same (?:pattern) syntax. See QString::split() and QStringList::join() for equivalents to Perl's split and join functions. Note: because C++ transforms \\'s they must be written \e twice in code, e.g. \bold{\\b} must be written \bold{\\\\b}. \target code-examples \section1 Code Examples \code QRegExp rx("^\\d\\d?$"); // match integers 0 to 99 rx.indexIn("123"); // returns -1 (no match) rx.indexIn("-6"); // returns -1 (no match) rx.indexIn("6"); // returns 0 (matched as position 0) \endcode The third string matches '\underline{6}'. This is a simple validation regexp for integers in the range 0 to 99. \code QRegExp rx("^\\S+$"); // match strings without whitespace rx.indexIn("Hello world"); // returns -1 (no match) rx.indexIn("This_is-OK"); // returns 0 (matched at position 0) \endcode The second string matches '\underline{This_is-OK}'. We've used the character set abbreviation '\\S' (non-whitespace) and the anchors to match strings which contain no whitespace. In the following example we match strings containing 'mail' or 'letter' or 'correspondence' but only match whole words i.e. not 'email' \code QRegExp rx("\\b(mail|letter|correspondence)\\b"); rx.indexIn("I sent you an email"); // returns -1 (no match) rx.indexIn("Please write the letter"); // returns 17 \endcode The second string matches "Please write the \underline{letter}". The word 'letter' is also captured (because of the parentheses). We can see what text we've captured like this: \code QString captured = rx.cap(1); // captured == "letter" \endcode This will capture the text from the first set of capturing parentheses (counting capturing left parentheses from left to right). The parentheses are counted from 1 since cap(0) is the whole matched regexp (equivalent to '&' in most regexp engines). \code QRegExp rx("&(?!amp;)"); // match ampersands but not & QString line1 = "This & that"; line1.replace(rx, "&"); // line1 == "This & that" QString line2 = "His & hers & theirs"; line2.replace(rx, "&"); // line2 == "His & hers & theirs" \endcode Here we've passed the QRegExp to QString's replace() function to replace the matched text with new text. \code QString str = "One Eric another Eirik, and an Ericsson. " "How many Eiriks, Eric?"; QRegExp rx("\\b(Eric|Eirik)\\b"); // match Eric or Eirik int pos = 0; // where we are in the string int count = 0; // how many Eric and Eirik's we've counted while (pos >= 0) { pos = rx.indexIn(str, pos); if (pos >= 0) { ++pos; // move along in str ++count; // count our Eric or Eirik } } \endcode We've used the indexIn() function to repeatedly match the regexp in the string. Note that instead of moving forward by one character at a time \c pos++ we could have written \c {pos += rx.matchedLength()} to skip over the already matched string. The count will equal 3, matching 'One \underline{Eric} another \underline{Eirik}, and an Ericsson. How many Eiriks, \underline{Eric}?'; it doesn't match 'Ericsson' or 'Eiriks' because they are not bounded by non-word boundaries. One common use of regexps is to split lines of delimited data into their component fields. \code str = "Trolltech ASA\twww.trolltech.com\tNorway"; QString company, web, country; rx.setPattern("^([^\t]+)\t([^\t]+)\t([^\t]+)$"); if (rx.indexIn(str) != -1) { company = rx.cap(1); web = rx.cap(2); country = rx.cap(3); } \endcode In this example our input lines have the format company name, web address and country. Unfortunately the regexp is rather long and not very versatile -- the code will break if we add any more fields. A simpler and better solution is to look for the separator, '\\t' in this case, and take the surrounding text. The QString::split() function can take a separator string or regexp as an argument and split a string accordingly. \code QStringList field = str.split("\t"); \endcode Here field[0] is the company, field[1] the web address and so on. To imitate the matching of a shell we can use wildcard mode. \code QRegExp rx("*.html"); rx.setPatternSyntax(QRegExp::Wildcard); rx.exactMatch("index.html"); // returns true rx.exactMatch("default.htm"); // returns false rx.exactMatch("readme.txt"); // returns false \endcode Wildcard matching can be convenient because of its simplicity, but any wildcard regexp can be defined using full regexps, e.g. \bold{.*\.html$}. Notice that we can't match both \c .html and \c .htm files with a wildcard unless we use \bold{*.htm*} which will also match 'test.html.bak'. A full regexp gives us the precision we need, \bold{.*\\.html?$}. QRegExp can match case insensitively using setCaseSensitivity(), and can use non-greedy matching, see setMinimal(). By default QRegExp uses full regexps but this can be changed with setWildcard(). Searching can be forward with indexIn() or backward with lastIndexIn(). Captured text can be accessed using capturedTexts() which returns a string list of all captured strings, or using cap() which returns the captured string for the given index. The pos() function takes a match index and returns the position in the string where the match was made (or -1 if there was no match). \sa QString, QStringList, QRegExpValidator, QSortFilterProxyModel, {tools/regexp}{Regular Expression Example} */ const int NumBadChars = 64; #define BadChar(ch) ((ch).unicode() % NumBadChars) const int NoOccurrence = INT_MAX; const int EmptyCapture = INT_MAX; const int InftyLen = INT_MAX; const int InftyRep = 1025; const int EOS = -1; static bool isWord(QChar ch) { return ch.isLetterOrNumber() || ch.isMark() || ch == QLatin1Char('_'); } /* Merges two vectors of ints and puts the result into the first one. */ static void mergeInto(QVector *a, const QVector &b) { int asize = a->size(); int bsize = b.size(); if (asize == 0) { *a = b; #ifndef QT_NO_REGEXP_OPTIM } else if (bsize == 1 && a->at(asize - 1) < b.at(0)) { a->resize(asize + 1); (*a)[asize] = b.at(0); #endif } else if (bsize >= 1) { int csize = asize + bsize; QVector c(csize); int i = 0, j = 0, k = 0; while (i < asize) { if (j < bsize) { if (a->at(i) == b.at(j)) { ++i; --csize; } else if (a->at(i) < b.at(j)) { c[k++] = a->at(i++); } else { c[k++] = b.at(j++); } } else { memcpy(c.data() + k, a->constData() + i, (asize - i) * sizeof(int)); break; } } c.resize(csize); if (j < bsize) memcpy(c.data() + k, b.constData() + j, (bsize - j) * sizeof(int)); *a = c; } } #ifndef QT_NO_REGEXP_WILDCARD /* Translates a wildcard pattern to an equivalent regular expression pattern (e.g., *.cpp to .*\.cpp). */ static QString wc2rx(const QString &wc_str) { int wclen = wc_str.length(); QString rx; int i = 0; const QChar *wc = wc_str.unicode(); while (i < wclen) { QChar c = wc[i++]; switch (c.unicode()) { case '*': rx += QLatin1String(".*"); break; case '?': rx += QLatin1Char('.'); break; case '$': case '(': case ')': case '+': case '.': case '\\': case '^': case '{': case '|': case '}': rx += QLatin1Char('\\'); rx += c; break; case '[': rx += c; if (wc[i] == QLatin1Char('^')) rx += wc[i++]; if (i < wclen) { if (rx[i] == QLatin1Char(']')) rx += wc[i++]; while (i < wclen && wc[i] != QLatin1Char(']')) { if (wc[i] == QLatin1Char('\\')) rx += QLatin1Char('\\'); rx += wc[i++]; } } break; default: rx += c; } } return rx; } #endif static int caretIndex(int offset, QRegExp::CaretMode caretMode) { if (caretMode == QRegExp::CaretAtZero) { return 0; } else if (caretMode == QRegExp::CaretAtOffset) { return offset; } else { // QRegExp::CaretWontMatch return -1; } } /* The QRegExpEngineKey struct uniquely identifies an engine. */ struct QRegExpEngineKey { QString pattern; QRegExp::PatternSyntax patternSyntax; Qt::CaseSensitivity cs; inline QRegExpEngineKey(const QString &pattern, QRegExp::PatternSyntax patternSyntax, Qt::CaseSensitivity cs) : pattern(pattern), patternSyntax(patternSyntax), cs(cs) {} inline void clear() { pattern.clear(); patternSyntax = QRegExp::RegExp; cs = Qt::CaseSensitive; } }; bool operator==(const QRegExpEngineKey &key1, const QRegExpEngineKey &key2) { return key1.pattern == key2.pattern && key1.patternSyntax == key2.patternSyntax && key1.cs == key2.cs; } class QRegExpEngine; //Q_DECLARE_TYPEINFO(QVector, Q_MOVABLE_TYPE); /* This is the engine state during matching. */ struct QRegExpMatchState { const QString *str; // a pointer to the input QString const QChar *in; // a pointer to the input string data int pos; // the current position in the string int caretPos; int len; // the length of the input string bool minimal; // minimal matching? QVector bigArray; // big QVector array int *inNextStack; // is state is nextStack? int *curStack; // stack of current states int *nextStack; // stack of next states int *curCapBegin; // start of current states' captures int *nextCapBegin; // start of next states' captures int *curCapEnd; // end of current states' captures int *nextCapEnd; // end of next states' captures int *tempCapBegin; // start of temporary captures int *tempCapEnd; // end of temporary captures int *capBegin; // start of captures for a next state int *capEnd; // end of captures for a next state int *slideTab; // bump-along slide table for bad-character heuristic int slideTabSize; // size of slide table #ifndef QT_NO_REGEXP_BACKREF QList > sleeping; // list of back-reference sleepers #endif int matchLen; // length of match int oneTestMatchedLen; // length of partial match QVector captured; // what match() returned last const QRegExpEngine *eng; inline QRegExpMatchState() { captured.fill(-1, 2); } void drain() { bigArray.clear(); } // to save memory void prepareForMatch(QRegExpEngine *eng); void match(const QString &str, int pos, bool minimal, bool oneTest, int caretIndex); bool matchHere(); bool testAnchor(int i, int a, const int *capBegin); }; /* The struct QRegExpAutomatonState represents one state in a modified NFA. The input characters matched are stored in the state instead of on the transitions, something possible for an automaton constructed from a regular expression. */ struct QRegExpAutomatonState { #ifndef QT_NO_REGEXP_CAPTURE int atom; // which atom does this state belong to? #endif int match; // what does it match? (see CharClassBit and BackRefBit) QVector outs; // out-transitions QMap reenter; // atoms reentered when transiting out QMap anchors; // anchors met when transiting out inline QRegExpAutomatonState() { } #ifndef QT_NO_REGEXP_CAPTURE inline QRegExpAutomatonState(int a, int m) : atom(a), match(m) { } #else inline QRegExpAutomatonState(int m) : match(m) { } #endif }; Q_DECLARE_TYPEINFO(QRegExpAutomatonState, Q_MOVABLE_TYPE); /* The struct QRegExpCharClassRange represents a range of characters (e.g., [0-9] denotes range 48 to 57). */ struct QRegExpCharClassRange { ushort from; // 48 ushort len; // 10 }; Q_DECLARE_TYPEINFO(QRegExpCharClassRange, Q_PRIMITIVE_TYPE); #ifndef QT_NO_REGEXP_CAPTURE /* The struct QRegExpAtom represents one node in the hierarchy of regular expression atoms. */ struct QRegExpAtom { enum { NoCapture = -1, OfficialCapture = -2, UnofficialCapture = -3 }; int parent; // index of parent in array of atoms int capture; // index of capture, from 1 to ncap - 1 }; Q_DECLARE_TYPEINFO(QRegExpAtom, Q_PRIMITIVE_TYPE); #endif struct QRegExpLookahead; #ifndef QT_NO_REGEXP_ANCHOR_ALT /* The struct QRegExpAnchorAlternation represents a pair of anchors with OR semantics. */ struct QRegExpAnchorAlternation { int a; // this anchor... int b; // ...or this one }; Q_DECLARE_TYPEINFO(QRegExpAnchorAlternation, Q_PRIMITIVE_TYPE); #endif #ifndef QT_NO_REGEXP_CCLASS /* The class QRegExpCharClass represents a set of characters, such as can be found in regular expressions (e.g., [a-z] denotes the set {a, b, ..., z}). */ class QRegExpCharClass { public: QRegExpCharClass(); inline QRegExpCharClass(const QRegExpCharClass &cc) { operator=(cc); } QRegExpCharClass &operator=(const QRegExpCharClass &cc); void clear(); bool negative() const { return n; } void setNegative(bool negative); void addCategories(int cats); void addRange(ushort from, ushort to); void addSingleton(ushort ch) { addRange(ch, ch); } bool in(QChar ch) const; #ifndef QT_NO_REGEXP_OPTIM const QVector &firstOccurrence() const { return occ1; } #endif #if defined(QT_DEBUG) void dump() const; #endif private: int c; // character classes QVector r; // character ranges bool n; // negative? #ifndef QT_NO_REGEXP_OPTIM QVector occ1; // first-occurrence array #endif }; #else struct QRegExpCharClass { int dummy; #ifndef QT_NO_REGEXP_OPTIM QRegExpCharClass() { occ1.fill(0, NumBadChars); } const QVector &firstOccurrence() const { return occ1; } QVector occ1; #endif }; #endif Q_DECLARE_TYPEINFO(QRegExpCharClass, Q_MOVABLE_TYPE); /* The QRegExpEngine class encapsulates a modified nondeterministic finite automaton (NFA). */ class QRegExpEngine { public: QRegExpEngine(Qt::CaseSensitivity cs, bool greedyQuantifiers) : cs(cs), greedyQuantifiers(greedyQuantifiers) { setup(); } QRegExpEngine(const QRegExpEngineKey &key); ~QRegExpEngine(); bool isValid() const { return valid; } const QString &errorString() const { return yyError; } int numCaptures() const { return officialncap; } int createState(QChar ch); int createState(const QRegExpCharClass &cc); #ifndef QT_NO_REGEXP_BACKREF int createState(int bref); #endif void addCatTransitions(const QVector &from, const QVector &to); #ifndef QT_NO_REGEXP_CAPTURE void addPlusTransitions(const QVector &from, const QVector &to, int atom); #endif #ifndef QT_NO_REGEXP_ANCHOR_ALT int anchorAlternation(int a, int b); int anchorConcatenation(int a, int b); #else int anchorAlternation(int a, int b) { return a & b; } int anchorConcatenation(int a, int b) { return a | b; } #endif void addAnchors(int from, int to, int a); #ifndef QT_NO_REGEXP_OPTIM void heuristicallyChooseHeuristic(); #endif #if defined(QT_DEBUG) void dump() const; #endif int ref; private: enum { CharClassBit = 0x10000, BackRefBit = 0x20000 }; enum { InitialState = 0, FinalState = 1 }; void setup(); int setupState(int match); /* Let's hope that 13 lookaheads and 14 back-references are enough. */ enum { MaxLookaheads = 13, MaxBackRefs = 14 }; enum { Anchor_Dollar = 0x00000001, Anchor_Caret = 0x00000002, Anchor_Word = 0x00000004, Anchor_NonWord = 0x00000008, Anchor_FirstLookahead = 0x00000010, Anchor_BackRef1Empty = Anchor_FirstLookahead << MaxLookaheads, Anchor_BackRef0Empty = Anchor_BackRef1Empty >> 1, Anchor_Alternation = Anchor_BackRef1Empty << MaxBackRefs, Anchor_LookaheadMask = (Anchor_FirstLookahead - 1) ^ ((Anchor_FirstLookahead << MaxLookaheads) - 1) }; #ifndef QT_NO_REGEXP_CAPTURE int startAtom(bool officialCapture); void finishAtom(int atom, bool needCapture); #endif #ifndef QT_NO_REGEXP_LOOKAHEAD int addLookahead(QRegExpEngine *eng, bool negative); #endif #ifndef QT_NO_REGEXP_OPTIM bool goodStringMatch(QRegExpMatchState &matchState) const; bool badCharMatch(QRegExpMatchState &matchState) const; #else bool bruteMatch(QRegExpMatchState &matchState) const; #endif QVector s; // array of states #ifndef QT_NO_REGEXP_CAPTURE QVector f; // atom hierarchy int nf; // number of atoms int cf; // current atom QVector captureForOfficialCapture; #endif int officialncap; // number of captures, seen from the outside int ncap; // number of captures, seen from the inside #ifndef QT_NO_REGEXP_CCLASS QVector cl; // array of character classes #endif #ifndef QT_NO_REGEXP_LOOKAHEAD QVector ahead; // array of lookaheads #endif #ifndef QT_NO_REGEXP_ANCHOR_ALT QVector aa; // array of (a, b) pairs of anchors #endif #ifndef QT_NO_REGEXP_OPTIM bool caretAnchored; // does the regexp start with ^? bool trivial; // is the good-string all that needs to match? #endif bool valid; // is the regular expression valid? Qt::CaseSensitivity cs; // case sensitive? bool greedyQuantifiers; // RegExp2? #ifndef QT_NO_REGEXP_BACKREF int nbrefs; // number of back-references #endif #ifndef QT_NO_REGEXP_OPTIM bool useGoodStringHeuristic; // use goodStringMatch? otherwise badCharMatch int goodEarlyStart; // the index where goodStr can first occur in a match int goodLateStart; // the index where goodStr can last occur in a match QString goodStr; // the string that any match has to contain int minl; // the minimum length of a match QVector occ1; // first-occurrence array #endif /* The class Box is an abstraction for a regular expression fragment. It can also be seen as one node in the syntax tree of a regular expression with synthetized attributes. Its interface is ugly for performance reasons. */ class Box { public: Box(QRegExpEngine *engine); Box(const Box &b) { operator=(b); } Box &operator=(const Box &b); void clear() { operator=(Box(eng)); } void set(QChar ch); void set(const QRegExpCharClass &cc); #ifndef QT_NO_REGEXP_BACKREF void set(int bref); #endif void cat(const Box &b); void orx(const Box &b); void plus(int atom); void opt(); void catAnchor(int a); #ifndef QT_NO_REGEXP_OPTIM void setupHeuristics(); #endif #if defined(QT_DEBUG) void dump() const; #endif private: void addAnchorsToEngine(const Box &to) const; QRegExpEngine *eng; // the automaton under construction QVector ls; // the left states (firstpos) QVector rs; // the right states (lastpos) QMap lanchors; // the left anchors QMap ranchors; // the right anchors int skipanchors; // the anchors to match if the box is skipped #ifndef QT_NO_REGEXP_OPTIM int earlyStart; // the index where str can first occur int lateStart; // the index where str can last occur QString str; // a string that has to occur in any match QString leftStr; // a string occurring at the left of this box QString rightStr; // a string occurring at the right of this box int maxl; // the maximum length of this box (possibly InftyLen) #endif int minl; // the minimum length of this box #ifndef QT_NO_REGEXP_OPTIM QVector occ1; // first-occurrence array #endif }; friend class Box; /* This is the lexical analyzer for regular expressions. */ enum { Tok_Eos, Tok_Dollar, Tok_LeftParen, Tok_MagicLeftParen, Tok_PosLookahead, Tok_NegLookahead, Tok_RightParen, Tok_CharClass, Tok_Caret, Tok_Quantifier, Tok_Bar, Tok_Word, Tok_NonWord, Tok_Char = 0x10000, Tok_BackRef = 0x20000 }; int getChar(); int getEscape(); #ifndef QT_NO_REGEXP_INTERVAL int getRep(int def); #endif #ifndef QT_NO_REGEXP_LOOKAHEAD void skipChars(int n); #endif void error(const char *msg); void startTokenizer(const QChar *rx, int len); int getToken(); const QChar *yyIn; // a pointer to the input regular expression pattern int yyPos0; // the position of yyTok in the input pattern int yyPos; // the position of the next character to read int yyLen; // the length of yyIn int yyCh; // the last character read QRegExpCharClass *yyCharClass; // attribute for Tok_CharClass tokens int yyMinRep; // attribute for Tok_Quantifier int yyMaxRep; // ditto QString yyError; // syntax error or overflow during parsing? /* This is the syntactic analyzer for regular expressions. */ int parse(const QChar *rx, int len); void parseAtom(Box *box); void parseFactor(Box *box); void parseTerm(Box *box); void parseExpression(Box *box); int yyTok; // the last token read bool yyMayCapture; // set this to false to disable capturing friend struct QRegExpMatchState; }; #ifndef QT_NO_REGEXP_LOOKAHEAD /* The struct QRegExpLookahead represents a lookahead a la Perl (e.g., (?=foo) and (?!bar)). */ struct QRegExpLookahead { QRegExpEngine *eng; // NFA representing the embedded regular expression bool neg; // negative lookahead? inline QRegExpLookahead(QRegExpEngine *eng0, bool neg0) : eng(eng0), neg(neg0) { } inline ~QRegExpLookahead() { delete eng; } }; #endif QRegExpEngine::QRegExpEngine(const QRegExpEngineKey &key) : cs(key.cs), greedyQuantifiers(key.patternSyntax == QRegExp::RegExp2) { setup(); QString rx; switch (key.patternSyntax) { case QRegExp::Wildcard: #ifndef QT_NO_REGEXP_WILDCARD rx = wc2rx(key.pattern); #endif break; case QRegExp::FixedString: rx = QRegExp::escape(key.pattern); break; default: rx = key.pattern; } valid = (parse(rx.unicode(), rx.length()) == rx.length()); if (!valid) { #ifndef QT_NO_REGEXP_OPTIM trivial = false; #endif error(RXERR_LEFTDELIM); } } QRegExpEngine::~QRegExpEngine() { #ifndef QT_NO_REGEXP_LOOKAHEAD qDeleteAll(ahead); #endif } void QRegExpMatchState::prepareForMatch(QRegExpEngine *eng) { /* We use one QVector for all the big data used a lot in matchHere() and friends. */ int ns = eng->s.size(); // number of states int ncap = eng->ncap; #ifndef QT_NO_REGEXP_OPTIM slideTabSize = qMax(eng->minl + 1, 16); #else slideTabSize = 0; #endif bigArray.resize((3 + 4 * ncap) * ns + 4 * ncap + slideTabSize); inNextStack = bigArray.data(); memset(inNextStack, -1, ns * sizeof(int)); curStack = inNextStack + ns; nextStack = inNextStack + 2 * ns; curCapBegin = inNextStack + 3 * ns; nextCapBegin = curCapBegin + ncap * ns; curCapEnd = curCapBegin + 2 * ncap * ns; nextCapEnd = curCapBegin + 3 * ncap * ns; tempCapBegin = curCapBegin + 4 * ncap * ns; tempCapEnd = tempCapBegin + ncap; capBegin = tempCapBegin + 2 * ncap; capEnd = tempCapBegin + 3 * ncap; slideTab = tempCapBegin + 4 * ncap; this->eng = eng; } /* Tries to match in str and returns an array of (begin, length) pairs for captured text. If there is no match, all pairs are (-1, -1). */ void QRegExpMatchState::match(const QString &str0, int pos0, bool minimal0, bool oneTest, int caretIndex) { bool matched = false; QChar char_null; #ifndef QT_NO_REGEXP_OPTIM if (eng->trivial && !oneTest) { pos = str0.indexOf(eng->goodStr, pos0, eng->cs); matchLen = eng->goodStr.length(); matched = (pos != -1); } else #endif { str = &str0; in = str0.unicode(); if (in == 0) in = &char_null; pos = pos0; caretPos = caretIndex; len = str0.length(); minimal = minimal0; matchLen = 0; oneTestMatchedLen = 0; if (eng->valid && pos >= 0 && pos <= len) { #ifndef QT_NO_REGEXP_OPTIM if (oneTest) { matched = matchHere(); } else { if (pos <= len - eng->minl) { if (eng->caretAnchored) { matched = matchHere(); } else if (eng->useGoodStringHeuristic) { matched = eng->goodStringMatch(*this); } else { matched = eng->badCharMatch(*this); } } } #else matched = oneTest ? matchHere() : eng->bruteMatch(*this); #endif } } int numCaptures = eng->numCaptures(); int capturedSize = 2 + 2 * numCaptures; captured.resize(capturedSize); if (matched) { int *c = captured.data(); *c++ = pos; *c++ = matchLen; #ifndef QT_NO_REGEXP_CAPTURE for (int i = 0; i < numCaptures; ++i) { int j = eng->captureForOfficialCapture.at(i); int len = capEnd[j] - capBegin[j]; *c++ = (len > 0) ? pos + capBegin[j] : 0; *c++ = len; } #endif } else { // we rely on 2's complement here memset(captured.data(), -1, capturedSize * sizeof(int)); } } /* The three following functions add one state to the automaton and return the number of the state. */ int QRegExpEngine::createState(QChar ch) { return setupState(ch.unicode()); } int QRegExpEngine::createState(const QRegExpCharClass &cc) { #ifndef QT_NO_REGEXP_CCLASS int n = cl.size(); cl += QRegExpCharClass(cc); return setupState(CharClassBit | n); #else Q_UNUSED(cc); return setupState(CharClassBit); #endif } #ifndef QT_NO_REGEXP_BACKREF int QRegExpEngine::createState(int bref) { if (bref > nbrefs) { nbrefs = bref; if (nbrefs > MaxBackRefs) { error(RXERR_LIMIT); return 0; } } return setupState(BackRefBit | bref); } #endif /* The two following functions add a transition between all pairs of states (i, j) where i is fond in from, and j is found in to. Cat-transitions are distinguished from plus-transitions for capturing. */ void QRegExpEngine::addCatTransitions(const QVector &from, const QVector &to) { for (int i = 0; i < from.size(); i++) mergeInto(&s[from.at(i)].outs, to); } #ifndef QT_NO_REGEXP_CAPTURE void QRegExpEngine::addPlusTransitions(const QVector &from, const QVector &to, int atom) { for (int i = 0; i < from.size(); i++) { QRegExpAutomatonState &st = s[from.at(i)]; const QVector oldOuts = st.outs; mergeInto(&st.outs, to); if (f.at(atom).capture != QRegExpAtom::NoCapture) { for (int j = 0; j < to.size(); j++) { // ### st.reenter.contains(to.at(j)) check looks suspicious if (!st.reenter.contains(to.at(j)) && qBinaryFind(oldOuts.begin(), oldOuts.end(), to.at(j)) == oldOuts.end()) st.reenter.insert(to.at(j), atom); } } } } #endif #ifndef QT_NO_REGEXP_ANCHOR_ALT /* Returns an anchor that means a OR b. */ int QRegExpEngine::anchorAlternation(int a, int b) { if (((a & b) == a || (a & b) == b) && ((a | b) & Anchor_Alternation) == 0) return a & b; int n = aa.size(); #ifndef QT_NO_REGEXP_OPTIM if (n > 0 && aa.at(n - 1).a == a && aa.at(n - 1).b == b) return Anchor_Alternation | (n - 1); #endif aa.resize(n + 1); aa[n].a = a; aa[n].b = b; return Anchor_Alternation | n; } /* Returns an anchor that means a AND b. */ int QRegExpEngine::anchorConcatenation(int a, int b) { if (((a | b) & Anchor_Alternation) == 0) return a | b; if ((b & Anchor_Alternation) != 0) qSwap(a, b); int aprime = anchorConcatenation(aa.at(a ^ Anchor_Alternation).a, b); int bprime = anchorConcatenation(aa.at(a ^ Anchor_Alternation).b, b); return anchorAlternation(aprime, bprime); } #endif /* Adds anchor a on a transition caracterised by its from state and its to state. */ void QRegExpEngine::addAnchors(int from, int to, int a) { QRegExpAutomatonState &st = s[from]; if (st.anchors.contains(to)) a = anchorAlternation(st.anchors.value(to), a); st.anchors.insert(to, a); } #ifndef QT_NO_REGEXP_OPTIM /* This function chooses between the good-string and the bad-character heuristics. It computes two scores and chooses the heuristic with the highest score. Here are some common-sense constraints on the scores that should be respected if the formulas are ever modified: (1) If goodStr is empty, the good-string heuristic scores 0. (2) If the regular expression is trivial, the good-string heuristic should be used. (3) If the search is case insensitive, the good-string heuristic should be used, unless it scores 0. (Case insensitivity turns all entries of occ1 to 0.) (4) If (goodLateStart - goodEarlyStart) is big, the good-string heuristic should score less. */ void QRegExpEngine::heuristicallyChooseHeuristic() { if (minl == 0) { useGoodStringHeuristic = false; } else if (trivial) { useGoodStringHeuristic = true; } else { /* Magic formula: The good string has to constitute a good proportion of the minimum-length string, and appear at a more-or-less known index. */ int goodStringScore = (64 * goodStr.length() / minl) - (goodLateStart - goodEarlyStart); /* Less magic formula: We pick some characters at random, and check whether they are good or bad. */ int badCharScore = 0; int step = qMax(1, NumBadChars / 32); for (int i = 1; i < NumBadChars; i += step) { if (occ1.at(i) == NoOccurrence) badCharScore += minl; else badCharScore += occ1.at(i); } badCharScore /= minl; useGoodStringHeuristic = (goodStringScore > badCharScore); } } #endif #if defined(QT_DEBUG) void QRegExpEngine::dump() const { int i, j; qDebug("Case %ssensitive engine", cs ? "" : "in"); qDebug(" States"); for (i = 0; i < s.size(); i++) { qDebug(" %d%s", i, i == InitialState ? " (initial)" : i == FinalState ? " (final)" : ""); #ifndef QT_NO_REGEXP_CAPTURE if (nf > 0) qDebug(" in atom %d", s[i].atom); #endif int m = s[i].match; if ((m & CharClassBit) != 0) { qDebug(" match character class %d", m ^ CharClassBit); #ifndef QT_NO_REGEXP_CCLASS cl[m ^ CharClassBit].dump(); #else qDebug(" negative character class"); #endif } else if ((m & BackRefBit) != 0) { qDebug(" match back-reference %d", m ^ BackRefBit); } else if (m >= 0x20 && m <= 0x7e) { qDebug(" match 0x%.4x (%c)", m, m); } else { qDebug(" match 0x%.4x", m); } for (j = 0; j < s[i].outs.size(); j++) { int next = s[i].outs[j]; qDebug(" -> %d", next); if (s[i].reenter.contains(next)) qDebug(" [reenter %d]", s[i].reenter[next]); if (s[i].anchors.value(next) != 0) qDebug(" [anchors 0x%.8x]", s[i].anchors[next]); } } #ifndef QT_NO_REGEXP_CAPTURE if (nf > 0) { qDebug(" Atom Parent Capture"); for (i = 0; i < nf; i++) { if (f[i].capture == QRegExpAtom::NoCapture) { qDebug(" %6d %6d nil", i, f[i].parent); } else { int cap = f[i].capture; bool official = captureForOfficialCapture.contains(cap); qDebug(" %6d %6d %6d %s", i, f[i].parent, f[i].capture, official ? "official" : ""); } } } #endif #ifndef QT_NO_REGEXP_ANCHOR_ALT for (i = 0; i < aa.size(); i++) qDebug(" Anchor alternation 0x%.8x: 0x%.8x 0x%.9x", i, aa[i].a, aa[i].b); #endif } #endif void QRegExpEngine::setup() { ref = 1; #ifndef QT_NO_REGEXP_CAPTURE f.resize(32); nf = 0; cf = -1; #endif officialncap = 0; ncap = 0; #ifndef QT_NO_REGEXP_OPTIM caretAnchored = true; trivial = true; #endif valid = false; #ifndef QT_NO_REGEXP_BACKREF nbrefs = 0; #endif #ifndef QT_NO_REGEXP_OPTIM useGoodStringHeuristic = true; minl = 0; occ1.fill(0, NumBadChars); #endif } int QRegExpEngine::setupState(int match) { #ifndef QT_NO_REGEXP_CAPTURE s += QRegExpAutomatonState(cf, match); #else s += QRegExpAutomatonState(match); #endif return s.size() - 1; } #ifndef QT_NO_REGEXP_CAPTURE /* Functions startAtom() and finishAtom() should be called to delimit atoms. When a state is created, it is assigned to the current atom. The information is later used for capturing. */ int QRegExpEngine::startAtom(bool officialCapture) { if ((nf & (nf + 1)) == 0 && nf + 1 >= f.size()) f.resize((nf + 1) << 1); f[nf].parent = cf; cf = nf++; f[cf].capture = officialCapture ? QRegExpAtom::OfficialCapture : QRegExpAtom::NoCapture; return cf; } void QRegExpEngine::finishAtom(int atom, bool needCapture) { if (greedyQuantifiers && needCapture && f[atom].capture == QRegExpAtom::NoCapture) f[atom].capture = QRegExpAtom::UnofficialCapture; cf = f.at(atom).parent; } #endif #ifndef QT_NO_REGEXP_LOOKAHEAD /* Creates a lookahead anchor. */ int QRegExpEngine::addLookahead(QRegExpEngine *eng, bool negative) { int n = ahead.size(); if (n == MaxLookaheads) { error(RXERR_LIMIT); return 0; } ahead += new QRegExpLookahead(eng, negative); return Anchor_FirstLookahead << n; } #endif #ifndef QT_NO_REGEXP_CAPTURE /* We want the longest leftmost captures. */ static bool isBetterCapture(int ncap, const int *begin1, const int *end1, const int *begin2, const int *end2) { for (int i = 0; i < ncap; i++) { int delta = begin2[i] - begin1[i]; // it has to start early... if (delta == 0) delta = end1[i] - end2[i]; // ...and end late if (delta != 0) return delta > 0; } return false; } #endif /* Returns true if anchor a matches at position pos + i in the input string, otherwise false. */ bool QRegExpMatchState::testAnchor(int i, int a, const int *capBegin) { int j; #ifndef QT_NO_REGEXP_ANCHOR_ALT if ((a & QRegExpEngine::Anchor_Alternation) != 0) return testAnchor(i, eng->aa.at(a ^ QRegExpEngine::Anchor_Alternation).a, capBegin) || testAnchor(i, eng->aa.at(a ^ QRegExpEngine::Anchor_Alternation).b, capBegin); #endif if ((a & QRegExpEngine::Anchor_Caret) != 0) { if (pos + i != caretPos) return false; } if ((a & QRegExpEngine::Anchor_Dollar) != 0) { if (pos + i != len) return false; } #ifndef QT_NO_REGEXP_ESCAPE if ((a & (QRegExpEngine::Anchor_Word | QRegExpEngine::Anchor_NonWord)) != 0) { bool before = false; bool after = false; if (pos + i != 0) before = isWord(in[pos + i - 1]); if (pos + i != len) after = isWord(in[pos + i]); if ((a & QRegExpEngine::Anchor_Word) != 0 && (before == after)) return false; if ((a & QRegExpEngine::Anchor_NonWord) != 0 && (before != after)) return false; } #endif #ifndef QT_NO_REGEXP_LOOKAHEAD if ((a & QRegExpEngine::Anchor_LookaheadMask) != 0) { QString cstr((QChar *) in + pos + i, len - pos - i); const QVector &ahead = eng->ahead; for (j = 0; j < ahead.size(); j++) { if ((a & (QRegExpEngine::Anchor_FirstLookahead << j)) != 0) { QRegExpMatchState matchState; matchState.prepareForMatch(ahead[j]->eng); matchState.match(cstr, 0, true, true, matchState.caretPos - matchState.pos - i); if ((matchState.captured.at(0) == 0) == ahead[j]->neg) return false; } } } #endif #ifndef QT_NO_REGEXP_CAPTURE #ifndef QT_NO_REGEXP_BACKREF for (j = 0; j < eng->nbrefs; j++) { if ((a & (QRegExpEngine::Anchor_BackRef1Empty << j)) != 0) { int i = eng->captureForOfficialCapture.at(j); if (capBegin[i] != EmptyCapture) return false; } } #endif #endif return true; } #ifndef QT_NO_REGEXP_OPTIM /* The three following functions are what Jeffrey Friedl would call transmissions (or bump-alongs). Using one or the other should make no difference except in performance. */ bool QRegExpEngine::goodStringMatch(QRegExpMatchState &matchState) const { int k = matchState.pos + goodEarlyStart; while ((k = matchState.str->indexOf(goodStr, k, cs)) != -1) { int from = k - goodLateStart; int to = k - goodEarlyStart; if (from > matchState.pos) matchState.pos = from; while (matchState.pos <= to) { if (matchState.matchHere()) return true; ++matchState.pos; } ++k; } return false; } bool QRegExpEngine::badCharMatch(QRegExpMatchState &matchState) const { int slideHead = 0; int slideNext = 0; int i; int lastPos = matchState.len - minl; memset(matchState.slideTab, 0, matchState.slideTabSize * sizeof(int)); /* Set up the slide table, used for the bad-character heuristic, using the table of first occurrence of each character. */ for (i = 0; i < minl; i++) { int sk = occ1[BadChar(matchState.in[matchState.pos + i])]; if (sk == NoOccurrence) sk = i + 1; if (sk > 0) { int k = i + 1 - sk; if (k < 0) { sk = i + 1; k = 0; } if (sk > matchState.slideTab[k]) matchState.slideTab[k] = sk; } } if (matchState.pos > lastPos) return false; for (;;) { if (++slideNext >= matchState.slideTabSize) slideNext = 0; if (matchState.slideTab[slideHead] > 0) { if (matchState.slideTab[slideHead] - 1 > matchState.slideTab[slideNext]) matchState.slideTab[slideNext] = matchState.slideTab[slideHead] - 1; matchState.slideTab[slideHead] = 0; } else { if (matchState.matchHere()) return true; } if (matchState.pos == lastPos) break; /* Update the slide table. This code has much in common with the initialization code. */ int sk = occ1[BadChar(matchState.in[matchState.pos + minl])]; if (sk == NoOccurrence) { matchState.slideTab[slideNext] = minl; } else if (sk > 0) { int k = slideNext + minl - sk; if (k >= matchState.slideTabSize) k -= matchState.slideTabSize; if (sk > matchState.slideTab[k]) matchState.slideTab[k] = sk; } slideHead = slideNext; ++matchState.pos; } return false; } #else bool QRegExpEngine::bruteMatch(QRegExpMatchState &matchState) const { while (matchState.pos <= matchState.len) { if (matchState.matchHere()) return true; ++matchState.pos; } return false; } #endif /* Here's the core of the engine. It tries to do a match here and now. */ bool QRegExpMatchState::matchHere() { int ncur = 1, nnext = 0; int i = 0, j, k, m; bool stop = false; matchLen = -1; oneTestMatchedLen = -1; curStack[0] = QRegExpEngine::InitialState; int ncap = eng->ncap; #ifndef QT_NO_REGEXP_CAPTURE if (ncap > 0) { for (j = 0; j < ncap; j++) { curCapBegin[j] = EmptyCapture; curCapEnd[j] = EmptyCapture; } } #endif #ifndef QT_NO_REGEXP_BACKREF while ((ncur > 0 || !sleeping.isEmpty()) && i <= len - pos && !stop) #else while (ncur > 0 && i <= len - pos && !stop) #endif { int ch = (i < len - pos) ? in[pos + i].unicode() : 0; for (j = 0; j < ncur; j++) { int cur = curStack[j]; const QRegExpAutomatonState &scur = eng->s.at(cur); const QVector &outs = scur.outs; for (k = 0; k < outs.size(); k++) { int next = outs.at(k); const QRegExpAutomatonState &snext = eng->s.at(next); bool inside = true; #if !defined(QT_NO_REGEXP_BACKREF) && !defined(QT_NO_REGEXP_CAPTURE) int needSomeSleep = 0; #endif /* First, check if the anchors are anchored properly. */ int a = scur.anchors.value(next); if (a != 0 && !testAnchor(i, a, curCapBegin + j * ncap)) inside = false; /* If indeed they are, check if the input character is correct for this transition. */ if (inside) { m = snext.match; if ((m & (QRegExpEngine::CharClassBit | QRegExpEngine::BackRefBit)) == 0) { if (eng->cs) inside = (m == ch); else inside = (QChar(m).toLower() == QChar(ch).toLower()); } else if (next == QRegExpEngine::FinalState) { matchLen = i; stop = minimal; inside = true; } else if ((m & QRegExpEngine::CharClassBit) != 0) { #ifndef QT_NO_REGEXP_CCLASS const QRegExpCharClass &cc = eng->cl.at(m ^ QRegExpEngine::CharClassBit); if (eng->cs) inside = cc.in(ch); else if (cc.negative()) inside = cc.in(QChar(ch).toLower()) && cc.in(QChar(ch).toUpper()); else inside = cc.in(QChar(ch).toLower()) || cc.in(QChar(ch).toUpper()); #endif #if !defined(QT_NO_REGEXP_BACKREF) && !defined(QT_NO_REGEXP_CAPTURE) } else { /* ((m & QRegExpEngine::BackRefBit) != 0) */ int bref = m ^ QRegExpEngine::BackRefBit; int ell = j * ncap + eng->captureForOfficialCapture.at(bref - 1); inside = bref <= ncap && curCapBegin[ell] != EmptyCapture; if (inside) { if (eng->cs) inside = (in[pos + curCapBegin[ell]] == QChar(ch)); else inside = (in[pos + curCapBegin[ell]].toLower() == QChar(ch).toLower()); } if (inside) { int delta; if (curCapEnd[ell] == EmptyCapture) delta = i - curCapBegin[ell]; else delta = curCapEnd[ell] - curCapBegin[ell]; inside = (delta <= len - (pos + i)); if (inside && delta > 1) { int n = 1; if (eng->cs) { while (n < delta) { if (in[pos + curCapBegin[ell] + n] != in[pos + i + n]) break; ++n; } } else { while (n < delta) { QChar a = in[pos + curCapBegin[ell] + n]; QChar b = in[pos + i + n]; if (a.toLower() != b.toLower()) break; ++n; } } inside = (n == delta); if (inside) needSomeSleep = delta - 1; } } #endif } } /* We must now update our data structures. */ if (inside) { #ifndef QT_NO_REGEXP_CAPTURE int *capBegin, *capEnd; #endif /* If the next state was not encountered yet, all is fine. */ if ((m = inNextStack[next]) == -1) { m = nnext++; nextStack[m] = next; inNextStack[next] = m; #ifndef QT_NO_REGEXP_CAPTURE capBegin = nextCapBegin + m * ncap; capEnd = nextCapEnd + m * ncap; /* Otherwise, we'll first maintain captures in temporary arrays, and decide at the end whether it's best to keep the previous capture zones or the new ones. */ } else { capBegin = tempCapBegin; capEnd = tempCapEnd; #endif } #ifndef QT_NO_REGEXP_CAPTURE /* Updating the capture zones is much of a task. */ if (ncap > 0) { memcpy(capBegin, curCapBegin + j * ncap, ncap * sizeof(int)); memcpy(capEnd, curCapEnd + j * ncap, ncap * sizeof(int)); int c = scur.atom, n = snext.atom; int p = -1, q = -1; int cap; /* Lemma 1. For any x in the range [0..nf), we have f[x].parent < x. Proof. By looking at startAtom(), it is clear that cf < nf holds all the time, and thus that f[nf].parent < nf. */ /* If we are reentering an atom, we empty all capture zones inside it. */ if ((q = scur.reenter.value(next)) != 0) { QBitArray b(eng->nf, false); b.setBit(q, true); for (int ell = q + 1; ell < eng->nf; ell++) { if (b.testBit(eng->f.at(ell).parent)) { b.setBit(ell, true); cap = eng->f.at(ell).capture; if (cap >= 0) { capBegin[cap] = EmptyCapture; capEnd[cap] = EmptyCapture; } } } p = eng->f.at(q).parent; /* Otherwise, close the capture zones we are leaving. We are leaving f[c].capture, f[f[c].parent].capture, f[f[f[c].parent].parent].capture, ..., until f[x].capture, with x such that f[x].parent is the youngest common ancestor for c and n. We go up along c's and n's ancestry until we find x. */ } else { p = c; q = n; while (p != q) { if (p > q) { cap = eng->f.at(p).capture; if (cap >= 0) { if (capBegin[cap] == i) { capBegin[cap] = EmptyCapture; capEnd[cap] = EmptyCapture; } else { capEnd[cap] = i; } } p = eng->f.at(p).parent; } else { q = eng->f.at(q).parent; } } } /* In any case, we now open the capture zones we are entering. We work upwards from n until we reach p (the parent of the atom we reenter or the youngest common ancestor). */ while (n > p) { cap = eng->f.at(n).capture; if (cap >= 0) { capBegin[cap] = i; capEnd[cap] = EmptyCapture; } n = eng->f.at(n).parent; } /* If the next state was already in nextStack, we must choose carefully which capture zones we want to keep. */ if (capBegin == tempCapBegin && isBetterCapture(ncap, capBegin, capEnd, nextCapBegin + m * ncap, nextCapEnd + m * ncap)) { memcpy(nextCapBegin + m * ncap, capBegin, ncap * sizeof(int)); memcpy(nextCapEnd + m * ncap, capEnd, ncap * sizeof(int)); } } #ifndef QT_NO_REGEXP_BACKREF /* We are done with updating the capture zones. It's now time to put the next state to sleep, if it needs to, and to remove it from nextStack. */ if (needSomeSleep > 0) { QVector zzZ(2 + 2 * ncap); zzZ[0] = i + needSomeSleep; zzZ[1] = next; if (ncap > 0) { memcpy(zzZ.data() + 2, capBegin, ncap * sizeof(int)); memcpy(zzZ.data() + 2 + ncap, capEnd, ncap * sizeof(int)); } inNextStack[nextStack[--nnext]] = -1; sleeping.append(zzZ); } #endif #endif } } } #ifndef QT_NO_REGEXP_CAPTURE /* If we reached the final state, hurray! Copy the captured zone. */ if (ncap > 0 && (m = inNextStack[QRegExpEngine::FinalState]) != -1) { memcpy(capBegin, nextCapBegin + m * ncap, ncap * sizeof(int)); memcpy(capEnd, nextCapEnd + m * ncap, ncap * sizeof(int)); } #ifndef QT_NO_REGEXP_BACKREF /* It's time to wake up the sleepers. */ j = 0; while (j < sleeping.count()) { if (sleeping.at(j)[0] == i) { const QVector &zzZ = sleeping.at(j); int next = zzZ[1]; const int *capBegin = zzZ.data() + 2; const int *capEnd = zzZ.data() + 2 + ncap; bool copyOver = true; if ((m = inNextStack[next]) == -1) { m = nnext++; nextStack[m] = next; inNextStack[next] = m; } else { copyOver = isBetterCapture(ncap, nextCapBegin + m * ncap, nextCapEnd + m * ncap, capBegin, capEnd); } if (copyOver) { memcpy(nextCapBegin + m * ncap, capBegin, ncap * sizeof(int)); memcpy(nextCapEnd + m * ncap, capEnd, ncap * sizeof(int)); } sleeping.removeAt(j); } else { ++j; } } #endif #endif for (j = 0; j < nnext; j++) inNextStack[nextStack[j]] = -1; // avoid needless iteration that confuses oneTestMatchedLen if (nnext == 1 && nextStack[0] == QRegExpEngine::FinalState #ifndef QT_NO_REGEXP_BACKREF && sleeping.isEmpty() #endif ) stop = true; qSwap(curStack, nextStack); #ifndef QT_NO_REGEXP_CAPTURE qSwap(curCapBegin, nextCapBegin); qSwap(curCapEnd, nextCapEnd); #endif ncur = nnext; nnext = 0; ++i; } #ifndef QT_NO_REGEXP_BACKREF /* If minimal matching is enabled, we might have some sleepers left. */ if (!sleeping.isEmpty()) sleeping.clear(); #endif oneTestMatchedLen = i - 1; return (matchLen >= 0); } #ifndef QT_NO_REGEXP_CCLASS QRegExpCharClass::QRegExpCharClass() : c(0), n(false) { #ifndef QT_NO_REGEXP_OPTIM occ1.fill(NoOccurrence, NumBadChars); #endif } QRegExpCharClass &QRegExpCharClass::operator=(const QRegExpCharClass &cc) { c = cc.c; r = cc.r; n = cc.n; #ifndef QT_NO_REGEXP_OPTIM occ1 = cc.occ1; #endif return *this; } void QRegExpCharClass::clear() { c = 0; r.resize(0); n = false; } void QRegExpCharClass::setNegative(bool negative) { n = negative; #ifndef QT_NO_REGEXP_OPTIM occ1.fill(0, NumBadChars); #endif } void QRegExpCharClass::addCategories(int cats) { c |= cats; #ifndef QT_NO_REGEXP_OPTIM occ1.fill(0, NumBadChars); #endif } void QRegExpCharClass::addRange(ushort from, ushort to) { if (from > to) qSwap(from, to); int m = r.size(); r.resize(m + 1); r[m].from = from; r[m].len = to - from + 1; #ifndef QT_NO_REGEXP_OPTIM int i; if (to - from < NumBadChars) { if (from % NumBadChars <= to % NumBadChars) { for (i = from % NumBadChars; i <= to % NumBadChars; i++) occ1[i] = 0; } else { for (i = 0; i <= to % NumBadChars; i++) occ1[i] = 0; for (i = from % NumBadChars; i < NumBadChars; i++) occ1[i] = 0; } } else { occ1.fill(0, NumBadChars); } #endif } bool QRegExpCharClass::in(QChar ch) const { #ifndef QT_NO_REGEXP_OPTIM if (occ1.at(BadChar(ch)) == NoOccurrence) return n; #endif if (c != 0 && (c & (1 << (int)ch.category())) != 0) return !n; const int uc = ch.unicode(); int size = r.size(); for (int i = 0; i < size; ++i) { const QRegExpCharClassRange &range = r.at(i); if (uint(uc - range.from) < uint(r.at(i).len)) return !n; } return n; } #if defined(QT_DEBUG) void QRegExpCharClass::dump() const { int i; qDebug(" %stive character class", n ? "nega" : "posi"); #ifndef QT_NO_REGEXP_CCLASS if (c != 0) qDebug(" categories 0x%.8x", c); #endif for (i = 0; i < r.size(); i++) qDebug(" 0x%.4x through 0x%.4x", r[i].from, r[i].from + r[i].len - 1); } #endif #endif QRegExpEngine::Box::Box(QRegExpEngine *engine) : eng(engine), skipanchors(0) #ifndef QT_NO_REGEXP_OPTIM , earlyStart(0), lateStart(0), maxl(0) #endif { #ifndef QT_NO_REGEXP_OPTIM occ1.fill(NoOccurrence, NumBadChars); #endif minl = 0; } QRegExpEngine::Box &QRegExpEngine::Box::operator=(const Box &b) { eng = b.eng; ls = b.ls; rs = b.rs; lanchors = b.lanchors; ranchors = b.ranchors; skipanchors = b.skipanchors; #ifndef QT_NO_REGEXP_OPTIM earlyStart = b.earlyStart; lateStart = b.lateStart; str = b.str; leftStr = b.leftStr; rightStr = b.rightStr; maxl = b.maxl; occ1 = b.occ1; #endif minl = b.minl; return *this; } void QRegExpEngine::Box::set(QChar ch) { ls.resize(1); ls[0] = eng->createState(ch); rs = ls; #ifndef QT_NO_REGEXP_OPTIM str = ch; leftStr = ch; rightStr = ch; maxl = 1; occ1[BadChar(ch)] = 0; #endif minl = 1; } void QRegExpEngine::Box::set(const QRegExpCharClass &cc) { ls.resize(1); ls[0] = eng->createState(cc); rs = ls; #ifndef QT_NO_REGEXP_OPTIM maxl = 1; occ1 = cc.firstOccurrence(); #endif minl = 1; } #ifndef QT_NO_REGEXP_BACKREF void QRegExpEngine::Box::set(int bref) { ls.resize(1); ls[0] = eng->createState(bref); rs = ls; if (bref >= 1 && bref <= MaxBackRefs) skipanchors = Anchor_BackRef0Empty << bref; #ifndef QT_NO_REGEXP_OPTIM maxl = InftyLen; #endif minl = 0; } #endif void QRegExpEngine::Box::cat(const Box &b) { eng->addCatTransitions(rs, b.ls); addAnchorsToEngine(b); if (minl == 0) { lanchors.unite(b.lanchors); if (skipanchors != 0) { for (int i = 0; i < b.ls.size(); i++) { int a = eng->anchorConcatenation(lanchors.value(b.ls.at(i), 0), skipanchors); lanchors.insert(b.ls.at(i), a); } } mergeInto(&ls, b.ls); } if (b.minl == 0) { ranchors.unite(b.ranchors); if (b.skipanchors != 0) { for (int i = 0; i < rs.size(); i++) { int a = eng->anchorConcatenation(ranchors.value(rs.at(i), 0), b.skipanchors); ranchors.insert(rs.at(i), a); } } mergeInto(&rs, b.rs); } else { ranchors = b.ranchors; rs = b.rs; } #ifndef QT_NO_REGEXP_OPTIM if (maxl != InftyLen) { if (rightStr.length() + b.leftStr.length() > qMax(str.length(), b.str.length())) { earlyStart = minl - rightStr.length(); lateStart = maxl - rightStr.length(); str = rightStr + b.leftStr; } else if (b.str.length() > str.length()) { earlyStart = minl + b.earlyStart; lateStart = maxl + b.lateStart; str = b.str; } } if (leftStr.length() == maxl) leftStr += b.leftStr; if (b.rightStr.length() == b.maxl) { rightStr += b.rightStr; } else { rightStr = b.rightStr; } if (maxl == InftyLen || b.maxl == InftyLen) { maxl = InftyLen; } else { maxl += b.maxl; } for (int i = 0; i < NumBadChars; i++) { if (b.occ1.at(i) != NoOccurrence && minl + b.occ1.at(i) < occ1.at(i)) occ1[i] = minl + b.occ1.at(i); } #endif minl += b.minl; if (minl == 0) skipanchors = eng->anchorConcatenation(skipanchors, b.skipanchors); else skipanchors = 0; } void QRegExpEngine::Box::orx(const Box &b) { mergeInto(&ls, b.ls); lanchors.unite(b.lanchors); mergeInto(&rs, b.rs); ranchors.unite(b.ranchors); if (b.minl == 0) { if (minl == 0) skipanchors = eng->anchorAlternation(skipanchors, b.skipanchors); else skipanchors = b.skipanchors; } #ifndef QT_NO_REGEXP_OPTIM for (int i = 0; i < NumBadChars; i++) { if (occ1.at(i) > b.occ1.at(i)) occ1[i] = b.occ1.at(i); } earlyStart = 0; lateStart = 0; str = QString(); leftStr = QString(); rightStr = QString(); if (b.maxl > maxl) maxl = b.maxl; #endif if (b.minl < minl) minl = b.minl; } void QRegExpEngine::Box::plus(int atom) { #ifndef QT_NO_REGEXP_CAPTURE eng->addPlusTransitions(rs, ls, atom); #else Q_UNUSED(atom); eng->addCatTransitions(rs, ls); #endif addAnchorsToEngine(*this); #ifndef QT_NO_REGEXP_OPTIM maxl = InftyLen; #endif } void QRegExpEngine::Box::opt() { #ifndef QT_NO_REGEXP_OPTIM earlyStart = 0; lateStart = 0; str = QString(); leftStr = QString(); rightStr = QString(); #endif skipanchors = 0; minl = 0; } void QRegExpEngine::Box::catAnchor(int a) { if (a != 0) { for (int i = 0; i < rs.size(); i++) { a = eng->anchorConcatenation(ranchors.value(rs.at(i), 0), a); ranchors.insert(rs.at(i), a); } if (minl == 0) skipanchors = eng->anchorConcatenation(skipanchors, a); } } #ifndef QT_NO_REGEXP_OPTIM void QRegExpEngine::Box::setupHeuristics() { eng->goodEarlyStart = earlyStart; eng->goodLateStart = lateStart; eng->goodStr = eng->cs ? str : str.toLower(); eng->minl = minl; if (eng->cs) { /* A regular expression such as 112|1 has occ1['2'] = 2 and minl = 1 at this point. An entry of occ1 has to be at most minl or infinity for the rest of the algorithm to go well. We waited until here before normalizing these cases (instead of doing it in Box::orx()) because sometimes things improve by themselves. Consider for example (112|1)34. */ for (int i = 0; i < NumBadChars; i++) { if (occ1.at(i) != NoOccurrence && occ1.at(i) >= minl) occ1[i] = minl; } eng->occ1 = occ1; } else { eng->occ1.fill(0, NumBadChars); } eng->heuristicallyChooseHeuristic(); } #endif #if defined(QT_DEBUG) void QRegExpEngine::Box::dump() const { int i; qDebug("Box of at least %d character%s", minl, minl == 1 ? "" : "s"); qDebug(" Left states:"); for (i = 0; i < ls.size(); i++) { if (lanchors.value(ls[i], 0) == 0) qDebug(" %d", ls[i]); else qDebug(" %d [anchors 0x%.8x]", ls[i], lanchors[ls[i]]); } qDebug(" Right states:"); for (i = 0; i < rs.size(); i++) { if (ranchors.value(rs[i], 0) == 0) qDebug(" %d", rs[i]); else qDebug(" %d [anchors 0x%.8x]", rs[i], ranchors[rs[i]]); } qDebug(" Skip anchors: 0x%.8x", skipanchors); } #endif void QRegExpEngine::Box::addAnchorsToEngine(const Box &to) const { for (int i = 0; i < to.ls.size(); i++) { for (int j = 0; j < rs.size(); j++) { int a = eng->anchorConcatenation(ranchors.value(rs.at(j), 0), to.lanchors.value(to.ls.at(i), 0)); eng->addAnchors(rs[j], to.ls[i], a); } } } int QRegExpEngine::getChar() { return (yyPos == yyLen) ? EOS : yyIn[yyPos++].unicode(); } int QRegExpEngine::getEscape() { #ifndef QT_NO_REGEXP_ESCAPE const char tab[] = "afnrtv"; // no b, as \b means word boundary const char backTab[] = "\a\f\n\r\t\v"; ushort low; int i; #endif ushort val; int prevCh = yyCh; if (prevCh == EOS) { error(RXERR_END); return Tok_Char | '\\'; } yyCh = getChar(); #ifndef QT_NO_REGEXP_ESCAPE if ((prevCh & ~0xff) == 0) { const char *p = strchr(tab, prevCh); if (p != 0) return Tok_Char | backTab[p - tab]; } #endif switch (prevCh) { #ifndef QT_NO_REGEXP_ESCAPE case '0': val = 0; for (i = 0; i < 3; i++) { if (yyCh >= '0' && yyCh <= '7') val = (val << 3) | (yyCh - '0'); else break; yyCh = getChar(); } if ((val & ~0377) != 0) error(RXERR_OCTAL); return Tok_Char | val; #endif #ifndef QT_NO_REGEXP_ESCAPE case 'B': return Tok_NonWord; #endif #ifndef QT_NO_REGEXP_CCLASS case 'D': // see QChar::isDigit() yyCharClass->addCategories(0x7fffffef); return Tok_CharClass; case 'S': // see QChar::isSpace() yyCharClass->addCategories(0x7ffff87f); yyCharClass->addRange(0x0000, 0x0008); yyCharClass->addRange(0x000e, 0x001f); yyCharClass->addRange(0x007f, 0x009f); return Tok_CharClass; case 'W': // see QChar::isLetterOrNumber() and QChar::isMark() yyCharClass->addCategories(0x7fe07f81); yyCharClass->addRange(0x203f, 0x2040); yyCharClass->addSingleton(0x2040); yyCharClass->addSingleton(0x2054); yyCharClass->addSingleton(0x30fb); yyCharClass->addRange(0xfe33, 0xfe34); yyCharClass->addRange(0xfe4d, 0xfe4f); yyCharClass->addSingleton(0xff3f); yyCharClass->addSingleton(0xff65); return Tok_CharClass; #endif #ifndef QT_NO_REGEXP_ESCAPE case 'b': return Tok_Word; #endif #ifndef QT_NO_REGEXP_CCLASS case 'd': // see QChar::isDigit() yyCharClass->addCategories(0x00000010); return Tok_CharClass; case 's': // see QChar::isSpace() yyCharClass->addCategories(0x00000380); yyCharClass->addRange(0x0009, 0x000d); return Tok_CharClass; case 'w': // see QChar::isLetterOrNumber() and QChar::isMark() yyCharClass->addCategories(0x000f807e); yyCharClass->addSingleton(0x005f); // '_' return Tok_CharClass; #endif #ifndef QT_NO_REGEXP_ESCAPE case 'x': val = 0; for (i = 0; i < 4; i++) { low = QChar(yyCh).toLower().unicode(); if (low >= '0' && low <= '9') val = (val << 4) | (low - '0'); else if (low >= 'a' && low <= 'f') val = (val << 4) | (low - 'a' + 10); else break; yyCh = getChar(); } return Tok_Char | val; #endif default: if (prevCh >= '1' && prevCh <= '9') { #ifndef QT_NO_REGEXP_BACKREF val = prevCh - '0'; while (yyCh >= '0' && yyCh <= '9') { val = (val * 10) + (yyCh - '0'); yyCh = getChar(); } return Tok_BackRef | val; #else error(RXERR_DISABLED); #endif } return Tok_Char | prevCh; } } #ifndef QT_NO_REGEXP_INTERVAL int QRegExpEngine::getRep(int def) { if (yyCh >= '0' && yyCh <= '9') { int rep = 0; do { rep = 10 * rep + yyCh - '0'; if (rep >= InftyRep) { error(RXERR_REPETITION); rep = def; } yyCh = getChar(); } while (yyCh >= '0' && yyCh <= '9'); return rep; } else { return def; } } #endif #ifndef QT_NO_REGEXP_LOOKAHEAD void QRegExpEngine::skipChars(int n) { if (n > 0) { yyPos += n - 1; yyCh = getChar(); } } #endif void QRegExpEngine::error(const char *msg) { if (yyError.isEmpty()) yyError = QLatin1String(msg); } void QRegExpEngine::startTokenizer(const QChar *rx, int len) { yyIn = rx; yyPos0 = 0; yyPos = 0; yyLen = len; yyCh = getChar(); yyCharClass = new QRegExpCharClass; yyMinRep = 0; yyMaxRep = 0; yyError = QString(); } int QRegExpEngine::getToken() { #ifndef QT_NO_REGEXP_CCLASS ushort pendingCh = 0; bool charPending; bool rangePending; int tok; #endif int prevCh = yyCh; yyPos0 = yyPos - 1; #ifndef QT_NO_REGEXP_CCLASS yyCharClass->clear(); #endif yyMinRep = 0; yyMaxRep = 0; yyCh = getChar(); switch (prevCh) { case EOS: yyPos0 = yyPos; return Tok_Eos; case '$': return Tok_Dollar; case '(': if (yyCh == '?') { prevCh = getChar(); yyCh = getChar(); switch (prevCh) { #ifndef QT_NO_REGEXP_LOOKAHEAD case '!': return Tok_NegLookahead; case '=': return Tok_PosLookahead; #endif case ':': return Tok_MagicLeftParen; default: error(RXERR_LOOKAHEAD); return Tok_MagicLeftParen; } } else { return Tok_LeftParen; } case ')': return Tok_RightParen; case '*': yyMinRep = 0; yyMaxRep = InftyRep; return Tok_Quantifier; case '+': yyMinRep = 1; yyMaxRep = InftyRep; return Tok_Quantifier; case '.': #ifndef QT_NO_REGEXP_CCLASS yyCharClass->setNegative(true); #endif return Tok_CharClass; case '?': yyMinRep = 0; yyMaxRep = 1; return Tok_Quantifier; case '[': #ifndef QT_NO_REGEXP_CCLASS if (yyCh == '^') { yyCharClass->setNegative(true); yyCh = getChar(); } charPending = false; rangePending = false; do { if (yyCh == '-' && charPending && !rangePending) { rangePending = true; yyCh = getChar(); } else { if (charPending && !rangePending) { yyCharClass->addSingleton(pendingCh); charPending = false; } if (yyCh == '\\') { yyCh = getChar(); tok = getEscape(); if (tok == Tok_Word) tok = '\b'; } else { tok = Tok_Char | yyCh; yyCh = getChar(); } if (tok == Tok_CharClass) { if (rangePending) { yyCharClass->addSingleton('-'); yyCharClass->addSingleton(pendingCh); charPending = false; rangePending = false; } } else if ((tok & Tok_Char) != 0) { if (rangePending) { yyCharClass->addRange(pendingCh, tok ^ Tok_Char); charPending = false; rangePending = false; } else { pendingCh = tok ^ Tok_Char; charPending = true; } } else { error(RXERR_CHARCLASS); } } } while (yyCh != ']' && yyCh != EOS); if (rangePending) yyCharClass->addSingleton('-'); if (charPending) yyCharClass->addSingleton(pendingCh); if (yyCh == EOS) error(RXERR_END); else yyCh = getChar(); return Tok_CharClass; #else error(RXERR_END); return Tok_Char | '['; #endif case '\\': return getEscape(); case ']': error(RXERR_LEFTDELIM); return Tok_Char | ']'; case '^': return Tok_Caret; case '{': #ifndef QT_NO_REGEXP_INTERVAL yyMinRep = getRep(0); yyMaxRep = yyMinRep; if (yyCh == ',') { yyCh = getChar(); yyMaxRep = getRep(InftyRep); } if (yyMaxRep < yyMinRep) qSwap(yyMinRep, yyMaxRep); if (yyCh != '}') error(RXERR_REPETITION); yyCh = getChar(); return Tok_Quantifier; #else error(RXERR_DISABLED); return Tok_Char | '{'; #endif case '|': return Tok_Bar; case '}': error(RXERR_LEFTDELIM); return Tok_Char | '}'; default: return Tok_Char | prevCh; } } int QRegExpEngine::parse(const QChar *pattern, int len) { valid = true; startTokenizer(pattern, len); yyTok = getToken(); #ifndef QT_NO_REGEXP_CAPTURE yyMayCapture = true; #else yyMayCapture = false; #endif #ifndef QT_NO_REGEXP_CAPTURE int atom = startAtom(false); #endif QRegExpCharClass anything; Box box(this); // create InitialState box.set(anything); Box rightBox(this); // create FinalState rightBox.set(anything); Box middleBox(this); parseExpression(&middleBox); #ifndef QT_NO_REGEXP_CAPTURE finishAtom(atom, false); #endif #ifndef QT_NO_REGEXP_OPTIM middleBox.setupHeuristics(); #endif box.cat(middleBox); box.cat(rightBox); delete yyCharClass; yyCharClass = 0; #ifndef QT_NO_REGEXP_CAPTURE for (int i = 0; i < nf; ++i) { switch (f[i].capture) { case QRegExpAtom::NoCapture: break; case QRegExpAtom::OfficialCapture: f[i].capture = ncap; captureForOfficialCapture.append(ncap); ++ncap; ++officialncap; break; case QRegExpAtom::UnofficialCapture: f[i].capture = greedyQuantifiers ? ncap++ : QRegExpAtom::NoCapture; } } #ifndef QT_NO_REGEXP_BACKREF #ifndef QT_NO_REGEXP_OPTIM if (officialncap == 0 && nbrefs == 0) { ncap = nf = 0; f.clear(); } #endif while (nbrefs > officialncap) { // in this case, captureForOfficialCapture.size() != officialncap captureForOfficialCapture.append(ncap); ++ncap; } #endif #endif if (!yyError.isEmpty()) return -1; #ifndef QT_NO_REGEXP_OPTIM const QRegExpAutomatonState &sinit = s.at(InitialState); caretAnchored = !sinit.anchors.isEmpty(); if (caretAnchored) { const QMap &anchors = sinit.anchors; QMap::const_iterator a; for (a = anchors.begin(); a != anchors.end(); ++a) { if ( #ifndef QT_NO_REGEXP_ANCHOR_ALT (*a & Anchor_Alternation) != 0 || #endif (*a & Anchor_Caret) == 0) { caretAnchored = false; break; } } } #endif // cleanup anchors int numStates = s.count(); for (int i = 0; i < numStates; ++i) { QRegExpAutomatonState &state = s[i]; if (!state.anchors.isEmpty()) { QMap::iterator a = state.anchors.begin(); while (a != state.anchors.constEnd()) { if (a.value() == 0) a = state.anchors.erase(a); else ++a; } } } return yyPos0; } void QRegExpEngine::parseAtom(Box *box) { #ifndef QT_NO_REGEXP_LOOKAHEAD QRegExpEngine *eng = 0; bool neg; int len; #endif if ((yyTok & Tok_Char) != 0) { box->set(QChar(yyTok ^ Tok_Char)); } else { #ifndef QT_NO_REGEXP_OPTIM trivial = false; #endif switch (yyTok) { case Tok_Dollar: box->catAnchor(Anchor_Dollar); break; case Tok_Caret: box->catAnchor(Anchor_Caret); break; #ifndef QT_NO_REGEXP_LOOKAHEAD case Tok_PosLookahead: case Tok_NegLookahead: neg = (yyTok == Tok_NegLookahead); eng = new QRegExpEngine(cs, greedyQuantifiers); len = eng->parse(yyIn + yyPos - 1, yyLen - yyPos + 1); if (len >= 0) skipChars(len); else error(RXERR_LOOKAHEAD); box->catAnchor(addLookahead(eng, neg)); yyTok = getToken(); if (yyTok != Tok_RightParen) error(RXERR_LOOKAHEAD); break; #endif #ifndef QT_NO_REGEXP_ESCAPE case Tok_Word: box->catAnchor(Anchor_Word); break; case Tok_NonWord: box->catAnchor(Anchor_NonWord); break; #endif case Tok_LeftParen: case Tok_MagicLeftParen: yyTok = getToken(); parseExpression(box); if (yyTok != Tok_RightParen) error(RXERR_END); break; case Tok_CharClass: box->set(*yyCharClass); break; case Tok_Quantifier: error(RXERR_REPETITION); break; default: #ifndef QT_NO_REGEXP_BACKREF if ((yyTok & Tok_BackRef) != 0) box->set(yyTok ^ Tok_BackRef); else #endif error(RXERR_DISABLED); } } yyTok = getToken(); } void QRegExpEngine::parseFactor(Box *box) { #ifndef QT_NO_REGEXP_CAPTURE int outerAtom = greedyQuantifiers ? startAtom(false) : -1; int innerAtom = startAtom(yyMayCapture && yyTok == Tok_LeftParen); bool magicLeftParen = (yyTok == Tok_MagicLeftParen); #else const int innerAtom = -1; #endif #ifndef QT_NO_REGEXP_INTERVAL #define YYREDO() \ yyIn = in, yyPos0 = pos0, yyPos = pos, yyLen = len, yyCh = ch, \ *yyCharClass = charClass, yyMinRep = 0, yyMaxRep = 0, yyTok = tok const QChar *in = yyIn; int pos0 = yyPos0; int pos = yyPos; int len = yyLen; int ch = yyCh; QRegExpCharClass charClass; if (yyTok == Tok_CharClass) charClass = *yyCharClass; int tok = yyTok; bool mayCapture = yyMayCapture; #endif parseAtom(box); #ifndef QT_NO_REGEXP_CAPTURE finishAtom(innerAtom, magicLeftParen); #endif bool hasQuantifier = (yyTok == Tok_Quantifier); if (hasQuantifier) { #ifndef QT_NO_REGEXP_OPTIM trivial = false; #endif if (yyMaxRep == InftyRep) { box->plus(innerAtom); #ifndef QT_NO_REGEXP_INTERVAL } else if (yyMaxRep == 0) { box->clear(); #endif } if (yyMinRep == 0) box->opt(); #ifndef QT_NO_REGEXP_INTERVAL yyMayCapture = false; int alpha = (yyMinRep == 0) ? 0 : yyMinRep - 1; int beta = (yyMaxRep == InftyRep) ? 0 : yyMaxRep - (alpha + 1); Box rightBox(this); int i; for (i = 0; i < beta; i++) { YYREDO(); Box leftBox(this); parseAtom(&leftBox); leftBox.cat(rightBox); leftBox.opt(); rightBox = leftBox; } for (i = 0; i < alpha; i++) { YYREDO(); Box leftBox(this); parseAtom(&leftBox); leftBox.cat(rightBox); rightBox = leftBox; } rightBox.cat(*box); *box = rightBox; #endif yyTok = getToken(); #ifndef QT_NO_REGEXP_INTERVAL yyMayCapture = mayCapture; #endif } #undef YYREDO #ifndef QT_NO_REGEXP_CAPTURE if (greedyQuantifiers) finishAtom(outerAtom, hasQuantifier); #endif } void QRegExpEngine::parseTerm(Box *box) { #ifndef QT_NO_REGEXP_OPTIM if (yyTok != Tok_Eos && yyTok != Tok_RightParen && yyTok != Tok_Bar) parseFactor(box); #endif while (yyTok != Tok_Eos && yyTok != Tok_RightParen && yyTok != Tok_Bar) { Box rightBox(this); parseFactor(&rightBox); box->cat(rightBox); } } void QRegExpEngine::parseExpression(Box *box) { parseTerm(box); while (yyTok == Tok_Bar) { #ifndef QT_NO_REGEXP_OPTIM trivial = false; #endif Box rightBox(this); yyTok = getToken(); parseTerm(&rightBox); box->orx(rightBox); } } /* The struct QRegExpPrivate contains the private data of a regular expression other than the automaton. It makes it possible for many QRegExp objects to use the same QRegExpEngine object with different QRegExpPrivate objects. */ struct QRegExpPrivate { QRegExpEngine *eng; QRegExpEngineKey engineKey; bool min; #ifndef QT_NO_REGEXP_CAPTURE QString t; // last string passed to QRegExp::indexIn() or lastIndexIn() QStringList capturedCache; // what QRegExp::capturedTexts() returned last #endif QRegExpMatchState matchState; inline QRegExpPrivate() : eng(0), engineKey(QString(), QRegExp::RegExp, Qt::CaseSensitive), min(false) {} inline QRegExpPrivate(const QRegExpEngineKey &key) : eng(0), engineKey(key), min(false) {} }; #if !defined(QT_NO_REGEXP_OPTIM) uint qHash(const QRegExpEngineKey &key) { return qHash(key.pattern); } typedef QCache EngineCache; Q_GLOBAL_STATIC(EngineCache, globalEngineCache) Q_GLOBAL_STATIC(QMutex, mutex) #endif // QT_NO_REGEXP_OPTIM static void derefEngine(QRegExpEngine *eng, const QRegExpEngineKey &key) { #if !defined(QT_NO_REGEXP_OPTIM) QMutexLocker locker(mutex()); #endif // QT_NO_REGEXP_OPTIM if (!--eng->ref) { #if !defined(QT_NO_REGEXP_OPTIM) if (globalEngineCache()) globalEngineCache()->insert(key, eng, 4 + key.pattern.length() / 4); else delete eng; #else Q_UNUSED(key); delete eng; #endif } } static void prepareEngine_helper(QRegExpPrivate *priv) { bool initMatchState; { #if !defined(QT_NO_REGEXP_OPTIM) // the mutex protects both the globalEngineCache() and the priv->eng pointer QMutexLocker locker(mutex()); #endif initMatchState = !priv->eng; #if !defined(QT_NO_REGEXP_OPTIM) if (!priv->eng) { priv->eng = globalEngineCache()->take(priv->engineKey); if (priv->eng != 0) ++priv->eng->ref; } #endif // QT_NO_REGEXP_OPTIM if (!priv->eng) priv->eng = new QRegExpEngine(priv->engineKey); } if (initMatchState) priv->matchState.captured.fill(-1, 2 + 2 * priv->eng->numCaptures()); } inline static void prepareEngine(QRegExpPrivate *priv) { if (priv->eng) return; prepareEngine_helper(priv); } static void prepareEngineForMatch(QRegExpPrivate *priv, const QString &str) { prepareEngine(priv); priv->matchState.prepareForMatch(priv->eng); #ifndef QT_NO_REGEXP_CAPTURE priv->t = str; priv->capturedCache.clear(); #else Q_UNUSED(str); #endif } static void invalidateEngine(QRegExpPrivate *priv) { if (priv->eng != 0) { derefEngine(priv->eng, priv->engineKey); priv->eng = 0; priv->matchState.drain(); } } /*! \enum QRegExp::CaretMode The CaretMode enum defines the different meanings of the caret (\bold{^}) in a regular expression. The possible values are: \value CaretAtZero The caret corresponds to index 0 in the searched string. \value CaretAtOffset The caret corresponds to the start offset of the search. \value CaretWontMatch The caret never matches. */ /*! \enum QRegExp::PatternSyntax The syntax used to interpret the meaning of the pattern. \value RegExp A rich Perl-like pattern matching syntax. This is the default. \value RegExp2 Like RegExp, but with \l{greedy quantifiers}. This will be the default in Qt 5. (Introduced in Qt 4.2.) \value Wildcard This provides a simple pattern matching syntax similar to that used by shells (command interpreters) for "file globbing". See \l{Wildcard Matching}. \value FixedString The pattern is a fixed string. This is equivalent to using the RegExp pattern on a string in which all metacharacters are escaped using escape(). \sa setPatternSyntax() */ /*! Constructs an empty regexp. \sa isValid(), errorString() */ QRegExp::QRegExp() { priv = new QRegExpPrivate; } /*! Constructs a regular expression object for the given \a pattern string. The pattern must be given using wildcard notation if \a syntax is \l Wildcard; the default is \l RegExp. The pattern is case sensitive, unless \a cs is Qt::CaseInsensitive. Matching is greedy (maximal), but can be changed by calling setMinimal(). \sa setPattern(), setCaseSensitivity(), setPatternSyntax() */ QRegExp::QRegExp(const QString &pattern, Qt::CaseSensitivity cs, PatternSyntax syntax) { priv = new QRegExpPrivate(QRegExpEngineKey(pattern, syntax, cs)); } /*! Constructs a regular expression as a copy of \a rx. \sa operator=() */ QRegExp::QRegExp(const QRegExp &rx) { priv = new QRegExpPrivate; operator=(rx); } /*! Destroys the regular expression and cleans up its internal data. */ QRegExp::~QRegExp() { invalidateEngine(priv); delete priv; } /*! Copies the regular expression \a rx and returns a reference to the copy. The case sensitivity, wildcard, and minimal matching options are also copied. */ QRegExp &QRegExp::operator=(const QRegExp &rx) { prepareEngine(rx.priv); // to allow sharing QRegExpEngine *otherEng = rx.priv->eng; if (otherEng) ++otherEng->ref; invalidateEngine(priv); priv->eng = otherEng; priv->engineKey = rx.priv->engineKey; priv->min = rx.priv->min; #ifndef QT_NO_REGEXP_CAPTURE priv->t = rx.priv->t; priv->capturedCache = rx.priv->capturedCache; #endif if (priv->eng) priv->matchState.prepareForMatch(priv->eng); priv->matchState.captured = rx.priv->matchState.captured; return *this; } /*! Returns true if this regular expression is equal to \a rx; otherwise returns false. Two QRegExp objects are equal if they have the same pattern strings and the same settings for case sensitivity, wildcard and minimal matching. */ bool QRegExp::operator==(const QRegExp &rx) const { return priv->engineKey == rx.priv->engineKey && priv->min == rx.priv->min; } /*! \fn bool QRegExp::operator!=(const QRegExp &rx) const Returns true if this regular expression is not equal to \a rx; otherwise returns false. \sa operator==() */ /*! Returns true if the pattern string is empty; otherwise returns false. If you call exactMatch() with an empty pattern on an empty string it will return true; otherwise it returns false since it operates over the whole string. If you call indexIn() with an empty pattern on \e any string it will return the start offset (0 by default) because the empty pattern matches the 'emptiness' at the start of the string. In this case the length of the match returned by matchedLength() will be 0. See QString::isEmpty(). */ bool QRegExp::isEmpty() const { return priv->engineKey.pattern.isEmpty(); } /*! Returns true if the regular expression is valid; otherwise returns false. An invalid regular expression never matches. The pattern \bold{[a-z} is an example of an invalid pattern, since it lacks a closing square bracket. Note that the validity of a regexp may also depend on the setting of the wildcard flag, for example \bold{*.html} is a valid wildcard regexp but an invalid full regexp. \sa errorString() */ bool QRegExp::isValid() const { if (priv->engineKey.pattern.isEmpty()) { return true; } else { prepareEngine(priv); return priv->eng->isValid(); } } /*! Returns the pattern string of the regular expression. The pattern has either regular expression syntax or wildcard syntax, depending on patternSyntax(). \sa patternSyntax(), caseSensitivity() */ QString QRegExp::pattern() const { return priv->engineKey.pattern; } /*! Sets the pattern string to \a pattern. The case sensitivity, wildcard, and minimal matching options are not changed. \sa setPatternSyntax(), setCaseSensitivity() */ void QRegExp::setPattern(const QString &pattern) { if (priv->engineKey.pattern != pattern) { invalidateEngine(priv); priv->engineKey.pattern = pattern; } } /*! Returns Qt::CaseSensitive if the regexp is matched case sensitively; otherwise returns Qt::CaseInsensitive. \sa patternSyntax(), pattern(), isMinimal() */ Qt::CaseSensitivity QRegExp::caseSensitivity() const { return priv->engineKey.cs; } /*! Sets case sensitive matching to \a cs. If \a cs is Qt::CaseSensitive, \bold{\\.txt$} matches \c{readme.txt} but not \c{README.TXT}. \sa setPatternSyntax(), setPattern(), setMinimal() */ void QRegExp::setCaseSensitivity(Qt::CaseSensitivity cs) { if ((bool)cs != (bool)priv->engineKey.cs) { invalidateEngine(priv); priv->engineKey.cs = cs; } } /*! Returns the syntax used by the regular expression. The default is QRegExp::RegExp. \sa pattern(), caseSensitivity() */ QRegExp::PatternSyntax QRegExp::patternSyntax() const { return priv->engineKey.patternSyntax; } /*! Sets the syntax mode for the regular expression. The default is QRegExp::RegExp. Setting \a syntax to QRegExp::Wildcard enables simple shell-like \l{wildcard matching}. For example, \bold{r*.txt} matches the string \c{readme.txt} in wildcard mode, but does not match \c{readme}. Setting \a syntax to QRegExp::FixedString means that the pattern is interpreted as a plain string. Special characters (e.g., backslash) don't need to be escaped then. \sa setPattern(), setCaseSensitivity(), escape() */ void QRegExp::setPatternSyntax(PatternSyntax syntax) { if (syntax != priv->engineKey.patternSyntax) { invalidateEngine(priv); priv->engineKey.patternSyntax = syntax; } } /*! Returns true if minimal (non-greedy) matching is enabled; otherwise returns false. \sa caseSensitivity() */ bool QRegExp::isMinimal() const { return priv->min; } /*! Enables or disables minimal matching. If \a minimal is false, matching is greedy (maximal) which is the default. For example, suppose we have the input string "We must be bold, very bold!" and the pattern \bold{.*}. With the default greedy (maximal) matching, the match is "We must be \underline{bold, very bold}!". But with minimal (non-greedy) matching, the first match is: "We must be \underline{bold}, very bold!" and the second match is "We must be bold, very \underline{bold}!". In practice we might use the pattern \bold{[^<]*\} instead, although this will still fail for nested tags. \sa setCaseSensitivity() */ void QRegExp::setMinimal(bool minimal) { priv->min = minimal; } /*! Returns true if \a str is matched exactly by this regular expression; otherwise returns false. You can determine how much of the string was matched by calling matchedLength(). For a given regexp string R, exactMatch("R") is the equivalent of indexIn("^R$") since exactMatch() effectively encloses the regexp in the start of string and end of string anchors, except that it sets matchedLength() differently. For example, if the regular expression is \bold{blue}, then exactMatch() returns true only for input \c blue. For inputs \c bluebell, \c blutak and \c lightblue, exactMatch() returns false and matchedLength() will return 4, 3 and 0 respectively. Although const, this function sets matchedLength(), capturedTexts(), and pos(). \sa indexIn(), lastIndexIn() */ bool QRegExp::exactMatch(const QString &str) const { prepareEngineForMatch(priv, str); priv->matchState.match(str, 0, priv->min, true, 0); if (priv->matchState.captured.at(1) == str.length()) { return true; } else { priv->matchState.captured[0] = 0; priv->matchState.captured[1] = priv->matchState.oneTestMatchedLen; return false; } } /*! Attempts to find a match in \a str from position \a offset (0 by default). If \a offset is -1, the search starts at the last character; if -2, at the next to last character; etc. Returns the position of the first match, or -1 if there was no match. The \a caretMode parameter can be used to instruct whether \bold{^} should match at index 0 or at \a offset. You might prefer to use QString::indexOf(), QString::contains(), or even QStringList::filter(). To replace matches use QString::replace(). Example: \code QString str = "offsets: 1.23 .50 71.00 6.00"; QRegExp rx("\\d*\\.\\d+"); // primitive floating point matching int count = 0; int pos = 0; while ((pos = rx.indexIn(str, pos)) != -1) { ++count; pos += rx.matchedLength(); } // pos will be 9, 14, 18 and finally 24; count will end up as 4 \endcode Although const, this function sets matchedLength(), capturedTexts() and pos(). If the QRegExp is a wildcard expression (see setPatternSyntax()) and want to test a string against the whole wildcard expression, use exactMatch() instead of this function. \sa lastIndexIn(), exactMatch() */ int QRegExp::indexIn(const QString &str, int offset, CaretMode caretMode) const { prepareEngineForMatch(priv, str); if (offset < 0) offset += str.length(); priv->matchState.match(str, offset, priv->min, false, caretIndex(offset, caretMode)); return priv->matchState.captured.at(0); } /*! Attempts to find a match backwards in \a str from position \a offset. If \a offset is -1 (the default), the search starts at the last character; if -2, at the next to last character; etc. Returns the position of the first match, or -1 if there was no match. The \a caretMode parameter can be used to instruct whether \bold{^} should match at index 0 or at \a offset. Although const, this function sets matchedLength(), capturedTexts() and pos(). \warning Searching backwards is much slower than searching forwards. \sa indexIn(), exactMatch() */ int QRegExp::lastIndexIn(const QString &str, int offset, CaretMode caretMode) const { prepareEngineForMatch(priv, str); if (offset < 0) offset += str.length(); if (offset < 0 || offset > str.length()) { priv->matchState.captured.fill(-1); return -1; } while (offset >= 0) { priv->matchState.match(str, offset, priv->min, true, caretIndex(offset, caretMode)); if (priv->matchState.captured.at(0) == offset) return offset; --offset; } return -1; } /*! Returns the length of the last matched string, or -1 if there was no match. \sa exactMatch(), indexIn(), lastIndexIn() */ int QRegExp::matchedLength() const { return priv->matchState.captured.at(1); } #ifndef QT_NO_REGEXP_CAPTURE /*! Returns the number of captures contained in the regular expression. */ int QRegExp::numCaptures() const { prepareEngine(priv); return priv->eng->numCaptures(); } /*! Returns a list of the captured text strings. The first string in the list is the entire matched string. Each subsequent list element contains a string that matched a (capturing) subexpression of the regexp. For example: \code QRegExp rx("(\\d+)(\\s*)(cm|inch(es)?)"); int pos = rx.indexIn("Length: 36 inches"); QStringList list = rx.capturedTexts(); // list is now ("36 inches", "36", " ", "inches", "es") \endcode The above example also captures elements that may be present but which we have no interest in. This problem can be solved by using non-capturing parentheses: \code QRegExp rx("(\\d+)(?:\\s*)(cm|inch(?:es)?)"); int pos = rx.indexIn("Length: 36 inches"); QStringList list = rx.capturedTexts(); // list is now ("36 inches", "36", "inches") \endcode Note that if you want to iterate over the list, you should iterate over a copy, e.g. \code QStringList list = rx.capturedTexts(); QStringList::iterator it = list.begin(); while (it != list.end()) { myProcessing(*it); ++it; } \endcode Some regexps can match an indeterminate number of times. For example if the input string is "Offsets: 12 14 99 231 7" and the regexp, \c{rx}, is \bold{(\\d+)+}, we would hope to get a list of all the numbers matched. However, after calling \c{rx.indexIn(str)}, capturedTexts() will return the list ("12", "12"), i.e. the entire match was "12" and the first subexpression matched was "12". The correct approach is to use cap() in a \l{QRegExp#cap_in_a_loop}{loop}. The order of elements in the string list is as follows. The first element is the entire matching string. Each subsequent element corresponds to the next capturing open left parentheses. Thus capturedTexts()[1] is the text of the first capturing parentheses, capturedTexts()[2] is the text of the second and so on (corresponding to $1, $2, etc., in some other regexp languages). \sa cap(), pos() */ QStringList QRegExp::capturedTexts() { if (priv->capturedCache.isEmpty()) { prepareEngine(priv); const QVector &captured = priv->matchState.captured; int n = captured.size(); for (int i = 0; i < n; i += 2) { QString m; if (captured.at(i + 1) == 0) m = QLatin1String(""); // ### Qt 5: don't distinguish between null and empty else if (captured.at(i) >= 0) m = priv->t.mid(captured.at(i), captured.at(i + 1)); priv->capturedCache.append(m); } priv->t.clear(); } return priv->capturedCache; } /*! Returns the text captured by the \a nth subexpression. The entire match has index 0 and the parenthesized subexpressions have indexes starting from 1 (excluding non-capturing parentheses). \code QRegExp rxlen("(\\d+)(?:\\s*)(cm|inch)"); int pos = rxlen.indexIn("Length: 189cm"); if (pos > -1) { QString value = rxlen.cap(1); // "189" QString unit = rxlen.cap(2); // "cm" // ... } \endcode The order of elements matched by cap() is as follows. The first element, cap(0), is the entire matching string. Each subsequent element corresponds to the next capturing open left parentheses. Thus cap(1) is the text of the first capturing parentheses, cap(2) is the text of the second, and so on. \sa capturedTexts(), pos() */ QString QRegExp::cap(int nth) { return capturedTexts().value(nth); } /*! Returns the position of the \a nth captured text in the searched string. If \a nth is 0 (the default), pos() returns the position of the whole match. Example: \code QRegExp rx("/([a-z]+)/([a-z]+)"); rx.indexIn("Output /dev/null"); // returns 7 (position of /dev/null) rx.pos(0); // returns 7 (position of /dev/null) rx.pos(1); // returns 8 (position of dev) rx.pos(2); // returns 12 (position of null) \endcode For zero-length matches, pos() always returns -1. (For example, if cap(4) would return an empty string, pos(4) returns -1.) This is a feature of the implementation. \sa cap(), capturedTexts() */ int QRegExp::pos(int nth) { if (nth < 0 || nth >= priv->matchState.captured.size() / 2) return -1; else return priv->matchState.captured.at(2 * nth); } /*! Returns a text string that explains why a regexp pattern is invalid the case being; otherwise returns "no error occurred". \sa isValid() */ QString QRegExp::errorString() { if (isValid()) { return QString::fromLatin1(RXERR_OK); } else { return priv->eng->errorString(); } } #endif /*! Returns the string \a str with every regexp special character escaped with a backslash. The special characters are $, (,), *, +, ., ?, [, \,], ^, {, | and }. Example: \code s1 = QRegExp::escape("bingo"); // s1 == "bingo" s2 = QRegExp::escape("f(x)"); // s2 == "f\\(x\\)" \endcode This function is useful to construct regexp patterns dynamically: \code QRegExp rx("(" + QRegExp::escape(name) + "|" + QRegExp::escape(alias) + ")"); \endcode \sa setPatternSyntax() */ QString QRegExp::escape(const QString &str) { static const char meta[] = "$()*+.?[\\]^{|}"; QString quoted = str; int i = 0; while (i < quoted.length()) { if (strchr(meta, quoted.at(i).toLatin1()) != 0) quoted.insert(i++, QLatin1Char('\\')); ++i; } return quoted; } /*! \fn bool QRegExp::caseSensitive() const Use \l caseSensitivity() instead. */ /*! \fn void QRegExp::setCaseSensitive(bool sensitive) Use \l setCaseSensitivity() instead. */ /*! \fn bool QRegExp::wildcard() const Use \l patternSyntax() instead. \oldcode bool wc = rx.wildcard(); \newcode bool wc = (rx.patternSyntax() == QRegExp::Wildcard); \endcode */ /*! \fn void QRegExp::setWildcard(bool wildcard) Use \l setPatternSyntax() instead. \oldcode rx.setWildcard(wc); \newcode rx.setPatternSyntax(wc ? QRegExp::Wildcard : QRegExp::RegExp); \endcode */ /*! \fn bool QRegExp::minimal() const Use \l isMinimal() instead. */ /*! \fn int QRegExp::search(const QString &str, int from = 0, CaretMode caretMode = CaretAtZero) const Use \l indexIn() instead. */ /*! \fn int QRegExp::searchRev(const QString &str, int from = -1, \ CaretMode caretMode = CaretAtZero) const Use \l lastIndexIn() instead. */ /*! \fn QRegExp::QRegExp(const QString &pattern, bool cs, bool wildcard = false) Use another constructor instead. \oldcode QRegExp rx("*.txt", false, true); \newcode QRegExp rx("*.txt", Qt::CaseInsensitive, QRegExp::Wildcard); \endcode */ #ifndef QT_NO_DATASTREAM /*! \relates QRegExp Writes the regular expression \a regExp to stream \a out. \sa {Format of the QDataStream Operators} */ QDataStream &operator<<(QDataStream &out, const QRegExp ®Exp) { return out << regExp.pattern() << (quint8)regExp.caseSensitivity() << (quint8)regExp.patternSyntax() << (quint8)!!regExp.isMinimal(); } /*! \relates QRegExp Reads a regular expression from stream \a in into \a regExp. \sa {Format of the QDataStream Operators} */ QDataStream &operator>>(QDataStream &in, QRegExp ®Exp) { QString pattern; quint8 cs; quint8 patternSyntax; quint8 isMinimal; in >> pattern >> cs >> patternSyntax >> isMinimal; QRegExp newRegExp(pattern, Qt::CaseSensitivity(cs), QRegExp::PatternSyntax(patternSyntax)); newRegExp.setMinimal(isMinimal); regExp = newRegExp; return in; } #endif