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** Implementation of QRegExp class
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#include "qregexp.h"
#ifndef QT_NO_REGEXP
#include "qmemarray.h"
#include "qbitarray.h"
#include "qcache.h"
#include "qcleanuphandler.h"
#include "qintdict.h"
#include "qmap.h"
#include "qptrvector.h"
#include "qstring.h"
#include "qtl.h"
#ifdef QT_THREAD_SUPPORT
#include "qmutexpool_p.h"
#endif // QT_THREAD_SUPPORT
#undef QT_TRANSLATE_NOOP
#define QT_TRANSLATE_NOOP( context, sourceText ) sourceText
#include <limits.h>
// 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 qregexp.h
\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' (globbing) mode which works in a
similar way to command shells. A good text on regexps is \e
{Mastering Regular Expressions: Powerful Techniques for Perl and
Other Tools} by Jeffrey E. Friedl, ISBN 1565922573.
Experienced regexp users may prefer to skip the introduction and
go directly to the relevant information.
\tableofcontents
\section1 Introduction
Regexps are built up from expressions, quantifiers, and assertions.
The simplest form of expression is simply a character, e.g.
<b>x</b> or <b>5</b>. An expression can also be a set of
characters. For example, <b>[ABCD]</b>, will match an <b>A</b> or
a <b>B</b> or a <b>C</b> or a <b>D</b>. As a shorthand we could
write this as <b>[A-D]</b>. If we want to match any of the
captital letters in the English alphabet we can write
<b>[A-Z]</b>. A quantifier tells the regexp engine how many
occurrences of the expression we want, e.g. <b>x{1,1}</b> means
match an <b>x</b> 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 <b> and its closing \c </b> you can only use a regexp if you
know that these tags are not nested; the html fragment, \c{<b>bold
<b>bolder</b></b>} 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
<b>[0-9]{1,1}</b> 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 <b>[0-9]{1,2}</b> 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 <b>^</b> (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 <b>$</b> (dollar) which when it is the last character in the
regexp means that the regexp must match until the end of the
string. So now our regexp is <b>^[0-9]{1,2}$</b>. Note that
assertions, such as <b>^</b> and <b>$</b>, do not match any
characters.
If you've seen regexps elsewhere they may have looked different from
the ones above. This is because some sets of characters and some
quantifiers are so common that they have special symbols to
represent them. <b>[0-9]</b> can be replaced with the symbol
<b>\d</b>. The quantifier to match exactly one occurrence,
<b>{1,1}</b>, can be replaced with the expression itself. This means
that <b>x{1,1}</b> is exactly the same as <b>x</b> alone. So our 0
to 99 matcher could be written <b>^\d{1,2}$</b>. Another way of
writing it would be <b>^\d\d{0,1}$</b>, i.e. from the start of the
string match a digit followed by zero or one digits. In practice
most people would write it <b>^\d\d?$</b>. The <b>?</b> is a
shorthand for the quantifier <b>{0,1}</b>, i.e. a minimum of no
occurrences a maximum of one occurrence. This is used to make an
expression optional. The regexp <b>^\d\d?$</b> 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, <b>m{1,1}a{1,1}i{1,1}l{1,1}</b>, but since
each expression itself is automatically quantified by <b>{1,1}</b>
we can simply write this as <b>mail</b>; 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
<b>mail|letter|correspondence</b> 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,
<b>(mail|letter|correspondence)</b>. Parentheses have two effects,
firstly they group expressions together and secondly they identify
parts of the regexp that we wish to \link #capturing-text capture
\endlink. 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 <b>\b</b> "word boundary":
<b>\b(mail|letter|correspondence)\b</b>. This regexp means "match
a word boundary followed by the expression in parentheses followed
by another word boundary". The <b>\b</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: <b>\&</b>, 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:
<b>\&(?!amp;)</b>. 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 <b>\\b(Eric|Eirik)\\b</b> and <b>\\bEi?ri[ck]\\b</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 <b>c</b>
\i Any character represents itself unless it has a special
regexp meaning. Thus <b>c</b> matches the character \e c.
\row \i <b>\\c</b>
\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 <b>\^</b>.
\row \i <b>\\a</b>
\i This matches the ASCII bell character (BEL, 0x07).
\row \i <b>\\f</b>
\i This matches the ASCII form feed character (FF, 0x0C).
\row \i <b>\\n</b>
\i This matches the ASCII line feed character (LF, 0x0A, Unix newline).
\row \i <b>\\r</b>
\i This matches the ASCII carriage return character (CR, 0x0D).
\row \i <b>\\t</b>
\i This matches the ASCII horizontal tab character (HT, 0x09).
\row \i <b>\\v</b>
\i This matches the ASCII vertical tab character (VT, 0x0B).
\row \i <b>\\xhhhh</b>
\i This matches the Unicode character corresponding to the
hexadecimal number hhhh (between 0x0000 and 0xFFFF). \0ooo
(i.e., \zero ooo) matches the ASCII/Latin-1 character
corresponding to the octal number ooo (between 0 and 0377).
\row \i <b>. (dot)</b>
\i This matches any character (including newline).
\row \i <b>\\d</b>
\i This matches a digit (QChar::isDigit()).
\row \i <b>\\D</b>
\i This matches a non-digit.
\row \i <b>\\s</b>
\i This matches a whitespace (QChar::isSpace()).
\row \i <b>\\S</b>
\i This matches a non-whitespace.
\row \i <b>\\w</b>
\i This matches a word character (QChar::isLetterOrNumber() or '_').
\row \i <b>\\W</b>
\i This matches a non-word character.
\row \i <b>\\n</b>
\i The n-th \link #capturing-text backreference \endlink,
e.g. \1, \2, etc.
\endtable
\e {Note that the C++ compiler transforms backslashes in strings
so to include a <b>\\</b> in a regexp you will need to enter it
twice, i.e. <b>\\\\</b>.}
\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 <b>^</b>
\i The caret negates the character set if it occurs as the
first character, i.e. immediately after the opening square
bracket. For example, <b>[abc]</b> matches 'a' or 'b' or 'c',
but <b>[^abc]</b> matches anything \e except 'a' or 'b' or
'c'.
\row \i <b>-</b>
\i The dash is used to indicate a range of characters, for
example <b>[W-Z]</b> 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, <b>[0-9]</b> matches a digit in Western alphabets but
<b>\d</b> 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
<b>{1,1}</b>, i.e. it should occur exactly once. In the following
list <b>\e {E}</b> 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 <b>\e {E}?</b>
\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 <b>\e {E}{0,1}</b>. For example <b>dents?</b>
will match 'dent' and 'dents'.
\row \i <b>\e {E}+</b>
\i Matches one or more occurrences of \e E. This is the same
as <b>\e {E}{1,MAXINT}</b>. For example, <b>0+</b> will match
'0', '00', '000', etc.
\row \i <b>\e {E}*</b>
\i Matches zero or more occurrences of \e E. This is the same
as <b>\e {E}{0,MAXINT}</b>. The <b>*</b> 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 <b>\s*$</b> 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
<b>\s+$</b> to match strings that have at least one
whitespace at the end.
\row \i <b>\e {E}{n}</b>
\i Matches exactly \e n occurrences of the expression. This
is the same as repeating the expression \e n times. For
example, <b>x{5}</b> is the same as <b>xxxxx</b>. It is also
the same as <b>\e {E}{n,n}</b>, e.g. <b>x{5,5}</b>.
\row \i <b>\e {E}{n,}</b>
\i Matches at least \e n occurrences of the expression. This
is the same as <b>\e {E}{n,MAXINT}</b>.
\row \i <b>\e {E}{,m}</b>
\i Matches at most \e m occurrences of the expression. This
is the same as <b>\e {E}{0,m}</b>.
\row \i <b>\e {E}{n,m}</b>
\i Matches at least \e n occurrences of the expression and at
most \e m occurrences of the expression.
\endtable
(MAXINT is implementation dependent but will not be smaller than
1024.)
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, <b>tag+</b> matches a 't' followed by
an 'a' followed by at least one 'g', whereas <b>(tag)+</b> matches
at least one occurrence of 'tag'.
Note that quantifiers are "greedy". They will match as much text
as they can. For example, <b>0+</b> will match as many zeros as it
can from the first zero it finds, e.g. '2.<u>000</u>5'.
Quantifiers can be made non-greedy, see setMinimal().
\target capturing-text
\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
<b>mail|letter|correspondence</b> 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 <b>(mail|letter|correspondence)</b>
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 <b>\b(\w+)\W+\1\b</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 parenthesised 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.
<b>(?:green|blue)</b>. 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 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 <b>\e {E}</b> stands for any expression.
\table
\row \i <b>^</b>
\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, <b>^#include</b> 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 <b>$</b>
\i The dollar signifies the end of the string. For example
<b>\d\s*$</b> will match strings which end with a digit
optionally followed by whitespace. If you wish to match a
literal \c{$} you must escape it by writing
\c{\\$}.
\row \i <b>\\b</b>
\i A word boundary. For example the regexp
<b>\\bOK\\b</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 <b>(\\bOK\\b)</b> and we have a match it will only
contain 'OK' even if the string is "Its <u>OK</u> now".
\row \i <b>\\B</b>
\i A non-word boundary. This assertion is true wherever
<b>\\b</b> is false. For example if we searched for
<b>\\Bon\\B</b> in "Left on" the match would fail (space
and end of string aren't non-word boundaries), but it would
match in "t<u>on</u>ne".
\row \i <b>(?=\e E)</b>
\i Positive lookahead. This assertion is true if the
expression matches at this point in the regexp. For example,
<b>const(?=\\s+char)</b> matches 'const' whenever it is
followed by 'char', as in 'static <u>const</u> char *'.
(Compare with <b>const\\s+char</b>, which matches 'static
<u>const char</u> *'.)
\row \i <b>(?!\e E)</b>
\i Negative lookahead. This assertion is true if the
expression does not match at this point in the regexp. For
example, <b>const(?!\\s+char)</b> matches 'const' \e except
when it is followed by 'char'.
\endtable
\target wildcard-matching
\section1 Wildcard Matching (globbing)
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 setWildcard() 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 <b>c</b>
\i Any character represents itself apart from those mentioned
below. Thus <b>c</b> matches the character \e c.
\row \i <b>?</b>
\i This matches any single character. It is the same as
<b>.</b> in full regexps.
\row \i <b>*</b>
\i This matches zero or more of any characters. It is the
same as <b>.*</b> in full regexps.
\row \i <b>[...]</b>
\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 <b>*.html</b>.
This will match zero or more characters followed by a dot followed
by 'h', 't', 'm' and 'l'.
\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.
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 <b>ro+?m</b> requires:
\code
QRegExp rx( "ro+m" );
rx.setMinimal( TRUE );
\endcode
The equivalent of Perl's \c{/i} option is
setCaseSensitive(FALSE).
Perl's \c{/g} option can be emulated using a \link
#cap_in_a_loop loop \endlink.
In QRegExp <b>.</b> 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, $2,
... correspond to cap(1) or capturedTexts()[1], cap(2) or
capturedTexts()[2], etc.
To substitute a pattern use QString::replace().
Perl's extended \c{/x} syntax is not supported, nor are
directives, e.g. (?i), or regexp comments, e.g. (?#comment). On
the other hand, C++'s rules for literal strings can be used to
achieve the same:
\code
QRegExp mark( "\\b" // word boundary
"[Mm]ark" // the word we want to match
);
\endcode
Both zero-width positive and zero-width negative lookahead
assertions (?=pattern) and (?!pattern) are supported with the same
syntax as Perl. Perl's lookbehind assertions, "independent"
subexpressions and conditional expressions are not supported.
Non-capturing parentheses are also supported, with the same
(?:pattern) syntax.
See QStringList::split() and QStringList::join() for equivalents
to Perl's split and join functions.
Note: because C++ transforms \\'s they must be written \e twice in
code, e.g. <b>\\b</b> must be written <b>\\\\b</b>.
\target code-examples
\section1 Code Examples
\code
QRegExp rx( "^\\d\\d?$" ); // match integers 0 to 99
rx.search( "123" ); // returns -1 (no match)
rx.search( "-6" ); // returns -1 (no match)
rx.search( "6" ); // returns 0 (matched as position 0)
\endcode
The third string matches '<u>6</u>'. This is a simple validation
regexp for integers in the range 0 to 99.
\code
QRegExp rx( "^\\S+$" ); // match strings without whitespace
rx.search( "Hello world" ); // returns -1 (no match)
rx.search( "This_is-OK" ); // returns 0 (matched at position 0)
\endcode
The second string matches '<u>This_is-OK</u>'. 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.search( "I sent you an email" ); // returns -1 (no match)
rx.search( "Please write the letter" ); // returns 17
\endcode
The second string matches "Please write the <u>letter</u>". 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.search( str, pos );
if ( pos >= 0 ) {
pos++; // move along in str
count++; // count our Eric or Eirik
}
}
\endcode
We've used the search() 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 <u>Eric</u> another
<u>Eirik</u>, and an Ericsson. How many Eiriks, <u>Eric</u>?'; 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 AS\twww.trolltech.com\tNorway";
QString company, web, country;
rx.setPattern( "^([^\t]+)\t([^\t]+)\t([^\t]+)$" );
if ( rx.search( 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
QStringList split() function can take a separator string or regexp
as an argument and split a string accordingly.
\code
QStringList field = QStringList::split( "\t", str );
\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" ); // invalid regexp: * doesn't quantify anything
rx.setWildcard( TRUE ); // now it's a valid wildcard regexp
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.
<b>.*\.html$</b>. Notice that we can't match both \c .html and \c
.htm files with a wildcard unless we use <b>*.htm*</b> which will
also match 'test.html.bak'. A full regexp gives us the precision
we need, <b>.*\\.html?$</b>.
QRegExp can match case insensitively using setCaseSensitive(), 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 search() or backward with
searchRev(). 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 QRegExpValidator QString QStringList
\target member-function-documentation
*/
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 == QChar( '_' );
}
/*
Merges two QMemArrays of ints and puts the result into the first one.
*/
static void mergeInto( QMemArray<int> *a, const QMemArray<int>& b )
{
int asize = a->size();
int bsize = b.size();
if ( asize == 0 ) {
*a = b.copy();
#ifndef QT_NO_REGEXP_OPTIM
} else if ( bsize == 1 && (*a)[asize - 1] < b[0] ) {
a->resize( asize + 1 );
(*a)[asize] = b[0];
#endif
} else if ( bsize >= 1 ) {
int csize = asize + bsize;
QMemArray<int> c( csize );
int i = 0, j = 0, k = 0;
while ( i < asize ) {
if ( j < bsize ) {
if ( (*a)[i] == b[j] ) {
i++;
csize--;
} else if ( (*a)[i] < b[j] ) {
c[k++] = (*a)[i++];
} else {
c[k++] = b[j++];
}
} else {
memcpy( c.data() + k, (*a).data() + i,
(asize - i) * sizeof(int) );
break;
}
}
c.resize( csize );
if ( j < bsize )
memcpy( c.data() + k, b.data() + j, (bsize - j) * sizeof(int) );
*a = c;
}
}
/*
Merges two disjoint QMaps of (int, int) pairs and puts the result into the
first one.
*/
static void mergeInto( QMap<int, int> *a, const QMap<int, int>& b )
{
QMap<int, int>::ConstIterator it;
for ( it = b.begin(); it != b.end(); ++it )
a->insert( it.key(), *it );
}
/*
Returns the value associated to key k in QMap m of (int, int) pairs, or 0 if
no such value is explicitly present.
*/
static int at( const QMap<int, int>& m, int k )
{
QMap<int, int>::ConstIterator it = m.find( k );
if ( it == m.end() )
return 0;
else
return *it;
}
#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 = QString::fromLatin1( "" );
int i = 0;
const QChar *wc = wc_str.unicode();
while ( i < wclen ) {
QChar c = wc[i++];
switch ( c.unicode() ) {
case '*':
rx += QString::fromLatin1( ".*" );
break;
case '?':
rx += QChar( '.' );
break;
case '$':
case '(':
case ')':
case '+':
case '.':
case '\\':
case '^':
case '{':
case '|':
case '}':
rx += QChar( '\\' );
rx += c;
break;
case '[':
rx += c;
if ( wc[i] == QChar('^') )
rx += wc[i++];
if ( i < wclen ) {
if ( rx[i] == ']' )
rx += wc[i++];
while ( i < wclen && wc[i] != QChar(']') ) {
if ( wc[i] == '\\' )
rx += QChar( '\\' );
rx += wc[i++];
}
}
break;
default:
rx += c;
}
}
return rx;
}
#endif
/*
The class QRegExpEngine encapsulates a modified nondeterministic
finite automaton (NFA).
*/
class QRegExpEngine : public QShared
{
public:
#ifndef QT_NO_REGEXP_CCLASS
/*
The class CharClass represents a set of characters, such as can
be found in regular expressions (e.g., [a-z] denotes the set
{a, b, ..., z}).
*/
class CharClass
{
public:
CharClass();
CharClass( const CharClass& cc ) { operator=( cc ); }
CharClass& operator=( const CharClass& 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 QMemArray<int>& firstOccurrence() const { return occ1; }
#endif
#if defined(QT_DEBUG)
void dump() const;
#endif
private:
/*
The struct Range represents a range of characters (e.g.,
[0-9] denotes range 48 to 57).
*/
struct Range
{
ushort from; // 48
ushort to; // 57
};
int c; // character classes
QMemArray<Range> r; // character ranges
bool n; // negative?
#ifndef QT_NO_REGEXP_OPTIM
QMemArray<int> occ1; // first-occurrence array
#endif
};
#else
struct CharClass
{
int dummy;
#ifndef QT_NO_REGEXP_OPTIM
CharClass() { occ1.fill( 0, NumBadChars ); }
const QMemArray<int>& firstOccurrence() const { return occ1; }
QMemArray<int> occ1;
#endif
};
#endif
QRegExpEngine( bool caseSensitive ) { setup( caseSensitive ); }
QRegExpEngine( const QString& rx, bool caseSensitive );
#ifndef QT_NO_REGEXP_OPTIM
~QRegExpEngine();
#endif
bool isValid() const { return valid; }
const QString& errorString() const { return yyError; }
bool caseSensitive() const { return cs; }
int numCaptures() const { return officialncap; }
QMemArray<int> match( const QString& str, int pos, bool minimal,
bool oneTest, int caretIndex );
int matchedLength() const { return mmMatchedLen; }
int createState( QChar ch );
int createState( const CharClass& cc );
#ifndef QT_NO_REGEXP_BACKREF
int createState( int bref );
#endif
void addCatTransitions( const QMemArray<int>& from,
const QMemArray<int>& to );
#ifndef QT_NO_REGEXP_CAPTURE
void addPlusTransitions( const QMemArray<int>& from,
const QMemArray<int>& 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 setupGoodStringHeuristic( int earlyStart, int lateStart,
const QString& str );
void setupBadCharHeuristic( int minLen, const QMemArray<int>& firstOcc );
void heuristicallyChooseHeuristic();
#endif
#if defined(QT_DEBUG)
void dump() const;
#endif
private:
enum { CharClassBit = 0x10000, BackRefBit = 0x20000 };
/*
The struct State 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 State
{
#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)
QMemArray<int> outs; // out-transitions
QMap<int, int> *reenter; // atoms reentered when transiting out
QMap<int, int> *anchors; // anchors met when transiting out
#ifndef QT_NO_REGEXP_CAPTURE
State( int a, int m )
: atom( a ), match( m ), reenter( 0 ), anchors( 0 ) { }
#else
State( int m )
: match( m ), reenter( 0 ), anchors( 0 ) { }
#endif
~State() { delete reenter; delete anchors; }
};
#ifndef QT_NO_REGEXP_LOOKAHEAD
/*
The struct Lookahead represents a lookahead a la Perl (e.g., (?=foo) and
(?!bar)).
*/
struct Lookahead
{
QRegExpEngine *eng; // NFA representing the embedded regular expression
bool neg; // negative lookahead?
Lookahead( QRegExpEngine *eng0, bool neg0 )
: eng( eng0 ), neg( neg0 ) { }
~Lookahead() { delete eng; }
};
#endif
#ifndef QT_NO_REGEXP_CAPTURE
/*
The struct Atom represents one node in the hierarchy of regular
expression atoms.
*/
struct Atom
{
int parent; // index of parent in array of atoms
int capture; // index of capture, from 1 to ncap
};
#endif
#ifndef QT_NO_REGEXP_ANCHOR_ALT
/*
The struct AnchorAlternation represents a pair of anchors with
OR semantics.
*/
struct AnchorAlternation
{
int a; // this anchor...
int b; // ...or this one
};
#endif
enum { InitialState = 0, FinalState = 1 };
void setup( bool caseSensitive );
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 capture );
void finishAtom( int atom ) { cf = f[atom].parent; }
#endif
#ifndef QT_NO_REGEXP_LOOKAHEAD
int addLookahead( QRegExpEngine *eng, bool negative );
#endif
#ifndef QT_NO_REGEXP_CAPTURE
bool isBetterCapture( const int *begin1, const int *end1, const int *begin2,
const int *end2 );
#endif
bool testAnchor( int i, int a, const int *capBegin );
#ifndef QT_NO_REGEXP_OPTIM
bool goodStringMatch();
bool badCharMatch();
#else
bool bruteMatch();
#endif
bool matchHere();
QPtrVector<State> s; // array of states
int ns; // number of states
#ifndef QT_NO_REGEXP_CAPTURE
QMemArray<Atom> f; // atom hierarchy
int nf; // number of atoms
int cf; // current atom
#endif
int officialncap; // number of captures, seen from the outside
int ncap; // number of captures, seen from the inside
#ifndef QT_NO_REGEXP_CCLASS
QPtrVector<CharClass> cl; // array of character classes
#endif
#ifndef QT_NO_REGEXP_LOOKAHEAD
QPtrVector<Lookahead> ahead; // array of lookaheads
#endif
#ifndef QT_NO_REGEXP_ANCHOR_ALT
QMemArray<AnchorAlternation> aa; // array of (a, b) pairs of anchors
#endif
#ifndef QT_NO_REGEXP_OPTIM
bool caretAnchored; // does the regexp start with ^?
#endif
bool valid; // is the regular expression valid?
bool cs; // case sensitive?
#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
QMemArray<int> 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.
It's 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 CharClass& 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
QMemArray<int> ls; // the left states (firstpos)
QMemArray<int> rs; // the right states (lastpos)
QMap<int, int> lanchors; // the left anchors
QMap<int, int> 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
QMemArray<int> 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
CharClass *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
/*
This is the engine state during matching.
*/
const QString *mmStr; // a pointer to the input QString
const QChar *mmIn; // a pointer to the input string data
int mmPos; // the current position in the string
int mmCaretPos;
int mmLen; // the length of the input string
bool mmMinimal; // minimal matching?
QMemArray<int> mmCaptured; // an array of pairs (start, len)
QMemArray<int> mmCapturedNoMatch; // an array of pairs (-1, -1)
QMemArray<int> mmBigArray; // big QMemArray<int> array
int *mmInNextStack; // is state is mmNextStack?
int *mmCurStack; // stack of current states
int *mmNextStack; // stack of next states
int *mmCurCapBegin; // start of current states' captures
int *mmNextCapBegin; // start of next states' captures
int *mmCurCapEnd; // end of current states' captures
int *mmNextCapEnd; // end of next states' captures
int *mmTempCapBegin; // start of temporary captures
int *mmTempCapEnd; // end of temporary captures
int *mmCapBegin; // start of captures for a next state
int *mmCapEnd; // end of captures for a next state
int *mmSlideTab; // bump-along slide table for bad-character heuristic
int mmSlideTabSize; // size of slide table
#ifndef QT_NO_REGEXP_BACKREF
QIntDict<int> mmSleeping; // dictionary of back-reference sleepers
#endif
int mmMatchLen; // length of match
int mmMatchedLen; // length of partial match
};
QRegExpEngine::QRegExpEngine( const QString& rx, bool caseSensitive )
#ifndef QT_NO_REGEXP_BACKREF
: mmSleeping( 101 )
#endif
{
setup( caseSensitive );
valid = ( parse(rx.unicode(), rx.length()) == (int) rx.length() );
if ( !valid )
error( RXERR_LEFTDELIM );
}
#ifndef QT_NO_REGEXP_OPTIM
QRegExpEngine::~QRegExpEngine()
{
}
#endif
/*
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).
*/
QMemArray<int> QRegExpEngine::match( const QString& str, int pos, bool minimal,
bool oneTest, int caretIndex )
{
mmStr = &str;
mmIn = str.unicode();
if ( mmIn == 0 )
mmIn = &QChar::null;
mmPos = pos;
mmCaretPos = caretIndex;
mmLen = str.length();
mmMinimal = minimal;
mmMatchLen = 0;
mmMatchedLen = 0;
bool matched = FALSE;
if ( valid && mmPos >= 0 && mmPos <= mmLen ) {
#ifndef QT_NO_REGEXP_OPTIM
if ( oneTest ) {
matched = matchHere();
} else {
if ( mmPos <= mmLen - minl ) {
if ( caretAnchored ) {
matched = matchHere();
} else if ( useGoodStringHeuristic ) {
matched = goodStringMatch();
} else {
matched = badCharMatch();
}
}
}
#else
matched = oneTest ? matchHere() : bruteMatch();
#endif
}
if ( matched ) {
mmCaptured.detach();
mmCaptured[0] = mmPos;
mmCaptured[1] = mmMatchLen;
for ( int j = 0; j < officialncap; j++ ) {
int len = mmCapEnd[j] - mmCapBegin[j];
mmCaptured[2 + 2 * j] = len > 0 ? mmPos + mmCapBegin[j] : 0;
mmCaptured[2 + 2 * j + 1] = len;
}
return mmCaptured;
} else {
return mmCapturedNoMatch;
}
}
/*
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 CharClass& cc )
{
#ifndef QT_NO_REGEXP_CCLASS
int n = cl.size();
cl.resize( n + 1 );
cl.insert( n, new CharClass(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 QMemArray<int>& from,
const QMemArray<int>& to )
{
for ( int i = 0; i < (int) from.size(); i++ ) {
State *st = s[from[i]];
mergeInto( &st->outs, to );
}
}
#ifndef QT_NO_REGEXP_CAPTURE
void QRegExpEngine::addPlusTransitions( const QMemArray<int>& from,
const QMemArray<int>& to, int atom )
{
for ( int i = 0; i < (int) from.size(); i++ ) {
State *st = s[from[i]];
QMemArray<int> oldOuts = st->outs.copy();
mergeInto( &st->outs, to );
if ( f[atom].capture >= 0 ) {
if ( st->reenter == 0 )
st->reenter = new QMap<int, int>;
for ( int j = 0; j < (int) to.size(); j++ ) {
if ( !st->reenter->contains(to[j]) &&
oldOuts.bsearch(to[j]) < 0 )
st->reenter->insert( to[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[n - 1].a == a && aa[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[a ^ Anchor_Alternation].a, b );
int bprime = anchorConcatenation( aa[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 )
{
State *st = s[from];
if ( st->anchors == 0 )
st->anchors = new QMap<int, int>;
if ( st->anchors->contains(to) )
a = anchorAlternation( (*st->anchors)[to], a );
st->anchors->insert( to, a );
}
#ifndef QT_NO_REGEXP_OPTIM
/*
The two following functions provide the engine with the information
needed by its matching heuristics.
*/
void QRegExpEngine::setupGoodStringHeuristic( int earlyStart, int lateStart,
const QString& str )
{
goodEarlyStart = earlyStart;
goodLateStart = lateStart;
goodStr = cs ? str : str.lower();
}
void QRegExpEngine::setupBadCharHeuristic( int minLen,
const QMemArray<int>& firstOcc )
{
minl = minLen;
if ( cs ) {
occ1 = firstOcc;
} else {
occ1.fill( 0, NumBadChars );
}
}
/*
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 search is
case insensitive, the good-string heuristic should be used, unless
it scores 0. (Case insensitivity turns all entries of occ1 to 0.)
(3) If (goodLateStart - goodEarlyStart) is big, the good-string
heuristic should score less.
*/
void QRegExpEngine::heuristicallyChooseHeuristic()
{
int i;
if ( minl == 0 )
return;
/*
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 a couple of characters at random,
and check whether they are good or bad.
*/
int badCharScore = 0;
int step = QMAX( 1, NumBadChars / 32 );
for ( i = 1; i < NumBadChars; i += step ) {
if ( occ1[i] == NoOccurrence )
badCharScore += minl;
else
badCharScore += occ1[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 < ns; i++ ) {
qDebug( " %d%s", i,
i == InitialState ? " (initial)" :
i == FinalState ? " (final)" : "" );
#ifndef QT_NO_REGEXP_CAPTURE
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 < (int) s[i]->outs.size(); j++ ) {
int next = s[i]->outs[j];
qDebug( " -> %d", next );
if ( s[i]->reenter != 0 && s[i]->reenter->contains(next) )
qDebug( " [reenter %d]", (*s[i]->reenter)[next] );
if ( s[i]->anchors != 0 && at(*s[i]->anchors, 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++ )
qDebug( " %6d %6d %6d", i, f[i].parent, f[i].capture );
}
#endif
#ifndef QT_NO_REGEXP_ANCHOR_ALT
for ( i = 0; i < (int) aa.size(); i++ )
qDebug( " Anchor alternation 0x%.8x: 0x%.8x 0x%.9x", i, aa[i].a,
aa[i].b );
#endif
}
#endif
void QRegExpEngine::setup( bool caseSensitive )
{
s.setAutoDelete( TRUE );
s.resize( 32 );
ns = 0;
#ifndef QT_NO_REGEXP_CAPTURE
f.resize( 32 );
nf = 0;
cf = -1;
#endif
officialncap = 0;
ncap = 0;
#ifndef QT_NO_REGEXP_CCLASS
cl.setAutoDelete( TRUE );
#endif
#ifndef QT_NO_REGEXP_LOOKAHEAD
ahead.setAutoDelete( TRUE );
#endif
#ifndef QT_NO_REGEXP_OPTIM
caretAnchored = TRUE;
#endif
valid = FALSE;
cs = caseSensitive;
#ifndef QT_NO_REGEXP_BACKREF
nbrefs = 0;
#endif
#ifndef QT_NO_REGEXP_OPTIM
useGoodStringHeuristic = FALSE;
minl = 0;
occ1.fill( 0, NumBadChars );
#endif
mmCapturedNoMatch.fill( -1, 2 );
}
int QRegExpEngine::setupState( int match )
{
if ( (ns & (ns + 1)) == 0 && ns + 1 >= (int) s.size() )
s.resize( (ns + 1) << 1 );
#ifndef QT_NO_REGEXP_CAPTURE
s.insert( ns, new State(cf, match) );
#else
s.insert( ns, new State(match) );
#endif
return ns++;
}
#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 capture )
{
if ( (nf & (nf + 1)) == 0 && nf + 1 >= (int) f.size() )
f.resize( (nf + 1) << 1 );
f[nf].parent = cf;
cf = nf++;
f[cf].capture = capture ? ncap++ : -1;
return cf;
}
#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.resize( n + 1 );
ahead.insert( n, new Lookahead(eng, negative) );
return Anchor_FirstLookahead << n;
}
#endif
#ifndef QT_NO_REGEXP_CAPTURE
/*
We want the longest leftmost captures.
*/
bool QRegExpEngine::isBetterCapture( 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 (like a party)
if ( delta != 0 )
return delta > 0;
}
return FALSE;
}
#endif
/*
Returns TRUE if anchor a matches at position mmPos + i in the input
string, otherwise FALSE.
*/
bool QRegExpEngine::testAnchor( int i, int a, const int *capBegin )
{
int j;
#ifndef QT_NO_REGEXP_ANCHOR_ALT
if ( (a & Anchor_Alternation) != 0 ) {
return testAnchor( i, aa[a ^ Anchor_Alternation].a, capBegin ) ||
testAnchor( i, aa[a ^ Anchor_Alternation].b, capBegin );
}
#endif
if ( (a & Anchor_Caret) != 0 ) {
if ( mmPos + i != mmCaretPos )
return FALSE;
}
if ( (a & Anchor_Dollar) != 0 ) {
if ( mmPos + i != mmLen )
return FALSE;
}
#ifndef QT_NO_REGEXP_ESCAPE
if ( (a & (Anchor_Word | Anchor_NonWord)) != 0 ) {
bool before = FALSE;
bool after = FALSE;
if ( mmPos + i != 0 )
before = isWord( mmIn[mmPos + i - 1] );
if ( mmPos + i != mmLen )
after = isWord( mmIn[mmPos + i] );
if ( (a & Anchor_Word) != 0 && (before == after) )
return FALSE;
if ( (a & Anchor_NonWord) != 0 && (before != after) )
return FALSE;
}
#endif
#ifndef QT_NO_REGEXP_LOOKAHEAD
bool catchx = TRUE;
if ( (a & Anchor_LookaheadMask) != 0 ) {
QConstString cstr = QConstString( (QChar *) mmIn + mmPos + i,
mmLen - mmPos - i );
for ( j = 0; j < (int) ahead.size(); j++ ) {
if ( (a & (Anchor_FirstLookahead << j)) != 0 ) {
catchx = ahead[j]->eng->match( cstr.string(), 0, TRUE, TRUE,
mmCaretPos - mmPos - i )[0] == 0;
if ( catchx == ahead[j]->neg )
return FALSE;
}
}
}
#endif
#ifndef QT_NO_REGEXP_CAPTURE
#ifndef QT_NO_REGEXP_BACKREF
for ( j = 0; j < nbrefs; j++ ) {
if ( (a & (Anchor_BackRef1Empty << j)) != 0 ) {
if ( capBegin[j] != 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()
{
int k = mmPos + goodEarlyStart;
while ( (k = mmStr->find(goodStr, k, cs)) != -1 ) {
int from = k - goodLateStart;
int to = k - goodEarlyStart;
if ( from > mmPos )
mmPos = from;
while ( mmPos <= to ) {
if ( matchHere() )
return TRUE;
mmPos++;
}
k++;
}
return FALSE;
}
bool QRegExpEngine::badCharMatch()
{
int slideHead = 0;
int slideNext = 0;
int i;
int lastPos = mmLen - minl;
memset( mmSlideTab, 0, mmSlideTabSize * 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(mmIn[mmPos + 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 > mmSlideTab[k] )
mmSlideTab[k] = sk;
}
}
if ( mmPos > lastPos )
return FALSE;
for ( ;; ) {
if ( ++slideNext >= mmSlideTabSize )
slideNext = 0;
if ( mmSlideTab[slideHead] > 0 ) {
if ( mmSlideTab[slideHead] - 1 > mmSlideTab[slideNext] )
mmSlideTab[slideNext] = mmSlideTab[slideHead] - 1;
mmSlideTab[slideHead] = 0;
} else {
if ( matchHere() )
return TRUE;
}
if ( mmPos == lastPos )
break;
/*
Update the slide table. This code has much in common with
the initialization code.
*/
int sk = occ1[BadChar(mmIn[mmPos + minl])];
if ( sk == NoOccurrence ) {
mmSlideTab[slideNext] = minl;
} else if ( sk > 0 ) {
int k = slideNext + minl - sk;
if ( k >= mmSlideTabSize )
k -= mmSlideTabSize;
if ( sk > mmSlideTab[k] )
mmSlideTab[k] = sk;
}
slideHead = slideNext;
mmPos++;
}
return FALSE;
}
#else
bool QRegExpEngine::bruteMatch()
{
while ( mmPos <= mmLen ) {
if ( matchHere() )
return TRUE;
mmPos++;
}
return FALSE;
}
#endif
/*
Here's the core of the engine. It tries to do a match here and now.
*/
bool QRegExpEngine::matchHere()
{
int ncur = 1, nnext = 0;
int i = 0, j, k, m;
bool stop = FALSE;
mmMatchLen = -1;
mmMatchedLen = -1;
mmCurStack[0] = InitialState;
#ifndef QT_NO_REGEXP_CAPTURE
if ( ncap > 0 ) {
for ( j = 0; j < ncap; j++ ) {
mmCurCapBegin[j] = EmptyCapture;
mmCurCapEnd[j] = EmptyCapture;
}
}
#endif
#ifndef QT_NO_REGEXP_BACKREF
int *zzZ = 0;
while ( (ncur > 0 || !mmSleeping.isEmpty()) && i <= mmLen - mmPos &&
!stop )
#else
while ( ncur > 0 && i <= mmLen - mmPos && !stop )
#endif
{
int ch = ( i < mmLen - mmPos ) ? mmIn[mmPos + i].unicode() : 0;
for ( j = 0; j < ncur; j++ ) {
int cur = mmCurStack[j];
State *scur = s[cur];
QMemArray<int>& outs = scur->outs;
for ( k = 0; k < (int) outs.size(); k++ ) {
int next = outs[k];
State *snext = s[next];
bool in = TRUE;
#ifndef QT_NO_REGEXP_BACKREF
int needSomeSleep = 0;
#endif
/*
First, check if the anchors are anchored properly.
*/
if ( scur->anchors != 0 ) {
int a = at( *scur->anchors, next );
if ( a != 0 && !testAnchor(i, a, mmCurCapBegin + j * ncap) )
in = FALSE;
}
/*
If indeed they are, check if the input character is
correct for this transition.
*/
if ( in ) {
m = snext->match;
if ( (m & (CharClassBit | BackRefBit)) == 0 ) {
if ( cs )
in = ( m == ch );
else
in = ( QChar(m).lower() == QChar(ch).lower() );
} else if ( next == FinalState ) {
mmMatchLen = i;
stop = mmMinimal;
in = TRUE;
} else if ( (m & CharClassBit) != 0 ) {
#ifndef QT_NO_REGEXP_CCLASS
const CharClass *cc = cl[m ^ CharClassBit];
if ( cs )
in = cc->in( ch );
else if ( cc->negative() )
in = cc->in( QChar(ch).lower() ) &&
cc->in( QChar(ch).upper() );
else
in = cc->in( QChar(ch).lower() ) ||
cc->in( QChar(ch).upper() );
#endif
#ifndef QT_NO_REGEXP_BACKREF
} else { /* ( (m & BackRefBit) != 0 ) */
int bref = m ^ BackRefBit;
int ell = j * ncap + ( bref - 1 );
in = bref <= ncap && mmCurCapBegin[ell] != EmptyCapture;
if ( in ) {
if ( cs )
in = ( mmIn[mmPos + mmCurCapBegin[ell]]
== QChar(ch) );
else
in = ( mmIn[mmPos + mmCurCapBegin[ell]].lower()
== QChar(ch).lower() );
}
if ( in ) {
int delta;
if ( mmCurCapEnd[ell] == EmptyCapture )
delta = i - mmCurCapBegin[ell];
else
delta = mmCurCapEnd[ell] - mmCurCapBegin[ell];
in = ( delta <= mmLen - (mmPos + i) );
if ( in && delta > 1 ) {
int n = 1;
if ( cs ) {
while ( n < delta ) {
if ( mmIn[mmPos +
mmCurCapBegin[ell] + n] !=
mmIn[mmPos + i + n] )
break;
n++;
}
} else {
while ( n < delta ) {
QChar a = mmIn[mmPos +
mmCurCapBegin[ell] + n];
QChar b = mmIn[mmPos + i + n];
if ( a.lower() != b.lower() )
break;
n++;
}
}
in = ( n == delta );
if ( in )
needSomeSleep = delta - 1;
}
}
#endif
}
}
/*
We must now update our data structures.
*/
if ( in ) {
#ifndef QT_NO_REGEXP_CAPTURE
int *capBegin, *capEnd;
#endif
/*
If the next state was not encountered yet, all
is fine.
*/
if ( (m = mmInNextStack[next]) == -1 ) {
m = nnext++;
mmNextStack[m] = next;
mmInNextStack[next] = m;
#ifndef QT_NO_REGEXP_CAPTURE
capBegin = mmNextCapBegin + m * ncap;
capEnd = mmNextCapEnd + 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 = mmTempCapBegin;
capEnd = mmTempCapEnd;
#endif
}
#ifndef QT_NO_REGEXP_CAPTURE
/*
Updating the capture zones is much of a task.
*/
if ( ncap > 0 ) {
memcpy( capBegin, mmCurCapBegin + j * ncap,
ncap * sizeof(int) );
memcpy( capEnd, mmCurCapEnd + 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 ( scur->reenter != 0 &&
(q = at(*scur->reenter, next)) != 0 ) {
QBitArray b;
b.fill( FALSE, nf );
b.setBit( q, TRUE );
for ( int ell = q + 1; ell < nf; ell++ ) {
if ( b.testBit(f[ell].parent) ) {
b.setBit( ell, TRUE );
cap = f[ell].capture;
if ( cap >= 0 ) {
capBegin[cap] = EmptyCapture;
capEnd[cap] = EmptyCapture;
}
}
}
p = f[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 = f[p].capture;
if ( cap >= 0 ) {
if ( capBegin[cap] == i ) {
capBegin[cap] = EmptyCapture;
capEnd[cap] = EmptyCapture;
} else {
capEnd[cap] = i;
}
}
p = f[p].parent;
} else {
q = f[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 = f[n].capture;
if ( cap >= 0 ) {
capBegin[cap] = i;
capEnd[cap] = EmptyCapture;
}
n = f[n].parent;
}
/*
If the next state was already in
mmNextStack, we must choose carefully which
capture zones we want to keep.
*/
if ( capBegin == mmTempCapBegin &&
isBetterCapture(capBegin, capEnd,
mmNextCapBegin + m * ncap,
mmNextCapEnd + m * ncap) ) {
memcpy( mmNextCapBegin + m * ncap, capBegin,
ncap * sizeof(int) );
memcpy( mmNextCapEnd + 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
mmNextStack.
*/
if ( needSomeSleep > 0 ) {
zzZ = new int[1 + 2 * ncap];
zzZ[0] = next;
if ( ncap > 0 ) {
memcpy( zzZ + 1, capBegin, ncap * sizeof(int) );
memcpy( zzZ + 1 + ncap, capEnd,
ncap * sizeof(int) );
}
mmInNextStack[mmNextStack[--nnext]] = -1;
mmSleeping.insert( i + needSomeSleep, zzZ );
}
#endif
#endif
}
}
}
#ifndef QT_NO_REGEXP_CAPTURE
/*
If we reached the final state, hurray! Copy the captured
zone.
*/
if ( ncap > 0 && (m = mmInNextStack[FinalState]) != -1 ) {
memcpy( mmCapBegin, mmNextCapBegin + m * ncap, ncap * sizeof(int) );
memcpy( mmCapEnd, mmNextCapEnd + m * ncap, ncap * sizeof(int) );
}
#ifndef QT_NO_REGEXP_BACKREF
/*
It's time to wake up the sleepers.
*/
if ( !mmSleeping.isEmpty() ) {
while ( (zzZ = mmSleeping.take(i)) != 0 ) {
int next = zzZ[0];
int *capBegin = zzZ + 1;
int *capEnd = zzZ + 1 + ncap;
bool copyOver = TRUE;
if ( (m = mmInNextStack[zzZ[0]]) == -1 ) {
m = nnext++;
mmNextStack[m] = next;
mmInNextStack[next] = m;
} else {
copyOver = isBetterCapture( mmNextCapBegin + m * ncap,
mmNextCapEnd + m * ncap,
capBegin, capEnd );
}
if ( copyOver ) {
memcpy( mmNextCapBegin + m * ncap, capBegin,
ncap * sizeof(int) );
memcpy( mmNextCapEnd + m * ncap, capEnd,
ncap * sizeof(int) );
}
delete[] zzZ;
}
}
#endif
#endif
for ( j = 0; j < nnext; j++ )
mmInNextStack[mmNextStack[j]] = -1;
// avoid needless iteration that confuses mmMatchedLen
if ( nnext == 1 && mmNextStack[0] == FinalState
#ifndef QT_NO_REGEXP_BACKREF
&& mmSleeping.isEmpty()
#endif
)
stop = TRUE;
qSwap( mmCurStack, mmNextStack );
#ifndef QT_NO_REGEXP_CAPTURE
qSwap( mmCurCapBegin, mmNextCapBegin );
qSwap( mmCurCapEnd, mmNextCapEnd );
#endif
ncur = nnext;
nnext = 0;
i++;
}
#ifndef QT_NO_REGEXP_BACKREF
/*
If minimal matching is enabled, we might have some sleepers
left.
*/
while ( !mmSleeping.isEmpty() ) {
zzZ = mmSleeping.take( *QIntDictIterator<int>(mmSleeping) );
delete[] zzZ;
}
#endif
mmMatchedLen = i - 1;
return ( mmMatchLen >= 0 );
}
#ifndef QT_NO_REGEXP_CCLASS
QRegExpEngine::CharClass::CharClass()
: c( 0 ), n( FALSE )
{
#ifndef QT_NO_REGEXP_OPTIM
occ1.fill( NoOccurrence, NumBadChars );
#endif
}
QRegExpEngine::CharClass& QRegExpEngine::CharClass::operator=(
const CharClass& cc )
{
c = cc.c;
r = cc.r.copy();
n = cc.n;
#ifndef QT_NO_REGEXP_OPTIM
occ1 = cc.occ1;
#endif
return *this;
}
void QRegExpEngine::CharClass::clear()
{
c = 0;
r.resize( 0 );
n = FALSE;
}
void QRegExpEngine::CharClass::setNegative( bool negative )
{
n = negative;
#ifndef QT_NO_REGEXP_OPTIM
occ1.fill( 0, NumBadChars );
#endif
}
void QRegExpEngine::CharClass::addCategories( int cats )
{
c |= cats;
#ifndef QT_NO_REGEXP_OPTIM
occ1.fill( 0, NumBadChars );
#endif
}
void QRegExpEngine::CharClass::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].to = to;
#ifndef QT_NO_REGEXP_OPTIM
int i;
if ( to - from < NumBadChars ) {
occ1.detach();
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 QRegExpEngine::CharClass::in( QChar ch ) const
{
#ifndef QT_NO_REGEXP_OPTIM
if ( occ1[BadChar(ch)] == NoOccurrence )
return n;
#endif
if ( c != 0 && (c & (1 << (int) ch.category())) != 0 )
return !n;
for ( int i = 0; i < (int) r.size(); i++ ) {
if ( ch.unicode() >= r[i].from && ch.unicode() <= r[i].to )
return !n;
}
return n;
}
#if defined(QT_DEBUG)
void QRegExpEngine::CharClass::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 < (int) r.size(); i++ )
qDebug( " 0x%.4x through 0x%.4x", r[i].from, r[i].to );
}
#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;
rs.detach();
#ifndef QT_NO_REGEXP_OPTIM
str = ch;
leftStr = ch;
rightStr = ch;
maxl = 1;
occ1.detach();
occ1[BadChar(ch)] = 0;
#endif
minl = 1;
}
void QRegExpEngine::Box::set( const CharClass& cc )
{
ls.resize( 1 );
ls[0] = eng->createState( cc );
rs = ls;
rs.detach();
#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;
rs.detach();
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 ) {
mergeInto( &lanchors, b.lanchors );
if ( skipanchors != 0 ) {
for ( int i = 0; i < (int) b.ls.size(); i++ ) {
int a = eng->anchorConcatenation( at(lanchors, b.ls[i]),
skipanchors );
lanchors.insert( b.ls[i], a );
}
}
mergeInto( &ls, b.ls );
}
if ( b.minl == 0 ) {
mergeInto( &ranchors, b.ranchors );
if ( b.skipanchors != 0 ) {
for ( int i = 0; i < (int) rs.size(); i++ ) {
int a = eng->anchorConcatenation( at(ranchors, rs[i]),
b.skipanchors );
ranchors.insert( rs[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 ( (int) leftStr.length() == maxl )
leftStr += b.leftStr;
if ( (int) b.rightStr.length() == b.maxl )
rightStr += b.rightStr;
else
rightStr = b.rightStr;
if ( maxl == InftyLen || b.maxl == InftyLen )
maxl = InftyLen;
else
maxl += b.maxl;
occ1.detach();
for ( int i = 0; i < NumBadChars; i++ ) {
if ( b.occ1[i] != NoOccurrence && minl + b.occ1[i] < occ1[i] )
occ1[i] = minl + b.occ1[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 );
mergeInto( &lanchors, b.lanchors );
mergeInto( &rs, b.rs );
mergeInto( &ranchors, b.ranchors );
if ( b.minl == 0 ) {
if ( minl == 0 )
skipanchors = eng->anchorAlternation( skipanchors, b.skipanchors );
else
skipanchors = b.skipanchors;
}
#ifndef QT_NO_REGEXP_OPTIM
occ1.detach();
for ( int i = 0; i < NumBadChars; i++ ) {
if ( occ1[i] > b.occ1[i] )
occ1[i] = b.occ1[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 < (int) rs.size(); i++ ) {
a = eng->anchorConcatenation( at(ranchors, rs[i]), a );
ranchors.insert( rs[i], a );
}
if ( minl == 0 )
skipanchors = eng->anchorConcatenation( skipanchors, a );
}
}
#ifndef QT_NO_REGEXP_OPTIM
void QRegExpEngine::Box::setupHeuristics()
{
eng->setupGoodStringHeuristic( earlyStart, lateStart, str );
/*
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[i] != NoOccurrence && occ1[i] >= minl )
occ1[i] = minl;
}
eng->setupBadCharHeuristic( minl, occ1 );
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 < (int) ls.size(); i++ ) {
if ( at(lanchors, ls[i]) == 0 )
qDebug( " %d", ls[i] );
else
qDebug( " %d [anchors 0x%.8x]", ls[i], lanchors[ls[i]] );
}
qDebug( " Right states:" );
for ( i = 0; i < (int) rs.size(); i++ ) {
if ( at(ranchors, rs[i]) == 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 < (int) to.ls.size(); i++ ) {
for ( int j = 0; j < (int) rs.size(); j++ ) {
int a = eng->anchorConcatenation( at(ranchors, rs[j]),
at(to.lanchors, to.ls[i]) );
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()
yyCharClass->addCategories( 0x7fe07f8f );
yyCharClass->addRange( 0x203f, 0x2040 );
yyCharClass->addSingleton( 0x2040 );
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()
yyCharClass->addCategories( 0x000f8070 );
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 ).lower();
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 = QString::fromLatin1( msg );
}
void QRegExpEngine::startTokenizer( const QChar *rx, int len )
{
yyIn = rx;
yyPos0 = 0;
yyPos = 0;
yyLen = len;
yyCh = getChar();
yyCharClass = new CharClass;
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
CharClass 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 );
#endif
#ifndef QT_NO_REGEXP_OPTIM
middleBox.setupHeuristics();
#endif
box.cat( middleBox );
box.cat( rightBox );
delete yyCharClass;
yyCharClass = 0;
officialncap = ncap;
#ifndef QT_NO_REGEXP_BACKREF
if ( nbrefs > ncap )
ncap = nbrefs;
#endif
mmCaptured.resize( 2 + 2 * officialncap );
mmCapturedNoMatch.fill( -1, 2 + 2 * officialncap );
/*
We use one QMemArray<int> for all the big data used a lot in
matchHere() and friends.
*/
#ifndef QT_NO_REGEXP_OPTIM
mmSlideTabSize = QMAX( minl + 1, 16 );
#else
mmSlideTabSize = 0;
#endif
mmBigArray.resize( (3 + 4 * ncap) * ns + 4 * ncap + mmSlideTabSize );
mmInNextStack = mmBigArray.data();
memset( mmInNextStack, -1, ns * sizeof(int) );
mmCurStack = mmInNextStack + ns;
mmNextStack = mmInNextStack + 2 * ns;
mmCurCapBegin = mmInNextStack + 3 * ns;
mmNextCapBegin = mmCurCapBegin + ncap * ns;
mmCurCapEnd = mmCurCapBegin + 2 * ncap * ns;
mmNextCapEnd = mmCurCapBegin + 3 * ncap * ns;
mmTempCapBegin = mmCurCapBegin + 4 * ncap * ns;
mmTempCapEnd = mmTempCapBegin + ncap;
mmCapBegin = mmTempCapBegin + 2 * ncap;
mmCapEnd = mmTempCapBegin + 3 * ncap;
mmSlideTab = mmTempCapBegin + 4 * ncap;
if ( !yyError.isEmpty() )
return -1;
#ifndef QT_NO_REGEXP_OPTIM
State *sinit = s[InitialState];
caretAnchored = ( sinit->anchors != 0 );
if ( caretAnchored ) {
QMap<int, int>& anchors = *sinit->anchors;
QMap<int, int>::ConstIterator a;
for ( a = anchors.begin(); a != anchors.end(); ++a ) {
#ifndef QT_NO_REGEXP_ANCHOR_ALT
if ( (*a & Anchor_Alternation) != 0 )
break;
#endif
if ( (*a & Anchor_Caret) == 0 ) {
caretAnchored = FALSE;
break;
}
}
}
#endif
return yyPos0;
}
void QRegExpEngine::parseAtom( Box *box )
{
#ifndef QT_NO_REGEXP_LOOKAHEAD
QRegExpEngine *eng = 0;
bool neg;
int len;
#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 );
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:
if ( (yyTok & Tok_Char) != 0 )
box->set( QChar(yyTok ^ Tok_Char) );
#ifndef QT_NO_REGEXP_BACKREF
else if ( (yyTok & Tok_BackRef) != 0 )
box->set( yyTok ^ Tok_BackRef );
#endif
else
error( RXERR_DISABLED );
}
yyTok = getToken();
}
void QRegExpEngine::parseFactor( Box *box )
{
#ifndef QT_NO_REGEXP_CAPTURE
int atom = startAtom( yyMayCapture && yyTok == Tok_LeftParen );
#else
static const int atom = 0;
#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;
CharClass charClass;
if ( yyTok == Tok_CharClass )
charClass = *yyCharClass;
int tok = yyTok;
bool mayCapture = yyMayCapture;
#endif
parseAtom( box );
#ifndef QT_NO_REGEXP_CAPTURE
finishAtom( atom );
#endif
if ( yyTok == Tok_Quantifier ) {
if ( yyMaxRep == InftyRep ) {
box->plus( atom );
#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
}
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 ) {
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
{
QString pattern; // regular-expression or wildcard pattern
QString rxpattern; // regular-expression pattern
#ifndef QT_NO_REGEXP_WILDCARD
bool wc; // wildcard mode?
#endif
bool min; // minimal matching? (instead of maximal)
#ifndef QT_NO_REGEXP_CAPTURE
QString t; // last string passed to QRegExp::search() or searchRev()
QStringList capturedCache; // what QRegExp::capturedTexts() returned last
#endif
QMemArray<int> captured; // what QRegExpEngine::search() returned last
QRegExpPrivate() { captured.fill( -1, 2 ); }
};
#ifndef QT_NO_REGEXP_OPTIM
static QCache<QRegExpEngine> *engineCache = 0;
static QSingleCleanupHandler<QCache<QRegExpEngine> > cleanup_cache;
#endif
static QRegExpEngine *newEngine( const QString& pattern, bool caseSensitive )
{
#ifndef QT_NO_REGEXP_OPTIM
if ( engineCache != 0 ) {
#ifdef QT_THREAD_SUPPORT
QMutexLocker locker( qt_global_mutexpool ?
qt_global_mutexpool->get( &engineCache ) : 0 );
#endif
QRegExpEngine *eng = engineCache->take( pattern );
if ( eng == 0 || eng->caseSensitive() != caseSensitive ) {
delete eng;
} else {
eng->ref();
return eng;
}
}
#endif
return new QRegExpEngine( pattern, caseSensitive );
}
static void derefEngine( QRegExpEngine *eng, const QString& pattern )
{
#ifdef QT_THREAD_SUPPORT
QMutexLocker locker( qt_global_mutexpool ?
qt_global_mutexpool->get( &engineCache ) : 0 );
#endif
if ( eng != 0 && eng->deref() ) {
#ifndef QT_NO_REGEXP_OPTIM
if ( engineCache == 0 ) {
engineCache = new QCache<QRegExpEngine>;
engineCache->setAutoDelete( TRUE );
cleanup_cache.set( &engineCache );
}
if ( !pattern.isNull() &&
engineCache->insert(pattern, eng, 4 + pattern.length() / 4) )
return;
#else
Q_UNUSED( pattern );
#endif
delete eng;
}
}
/*!
\enum QRegExp::CaretMode
The CaretMode enum defines the different meanings of the caret
(<b>^</b>) 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.
*/
/*!
Constructs an empty regexp.
\sa isValid() errorString()
*/
QRegExp::QRegExp()
{
eng = new QRegExpEngine( TRUE );
priv = new QRegExpPrivate;
#ifndef QT_NO_REGEXP_WILDCARD
priv->wc = FALSE;
#endif
priv->min = FALSE;
compile( TRUE );
}
/*!
Constructs a regular expression object for the given \a pattern
string. The pattern must be given using wildcard notation if \a
wildcard is TRUE (default is FALSE). The pattern is case
sensitive, unless \a caseSensitive is FALSE. Matching is greedy
(maximal), but can be changed by calling setMinimal().
\sa setPattern() setCaseSensitive() setWildcard() setMinimal()
*/
QRegExp::QRegExp( const QString& pattern, bool caseSensitive, bool wildcard )
{
eng = 0;
priv = new QRegExpPrivate;
priv->pattern = pattern;
#ifndef QT_NO_REGEXP_WILDCARD
priv->wc = wildcard;
#endif
priv->min = FALSE;
compile( caseSensitive );
}
/*!
Constructs a regular expression as a copy of \a rx.
\sa operator=()
*/
QRegExp::QRegExp( const QRegExp& rx )
{
eng = 0;
priv = new QRegExpPrivate;
operator=( rx );
}
/*!
Destroys the regular expression and cleans up its internal data.
*/
QRegExp::~QRegExp()
{
derefEngine( eng, priv->rxpattern );
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 )
{
rx.eng->ref();
derefEngine( eng, priv->rxpattern );
eng = rx.eng;
priv->pattern = rx.priv->pattern;
priv->rxpattern = rx.priv->rxpattern;
#ifndef QT_NO_REGEXP_WILDCARD
priv->wc = rx.priv->wc;
#endif
priv->min = rx.priv->min;
#ifndef QT_NO_REGEXP_CAPTURE
priv->t = rx.priv->t;
priv->capturedCache = rx.priv->capturedCache;
#endif
priv->captured = rx.priv->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->pattern == rx.priv->pattern &&
eng->caseSensitive() == rx.eng->caseSensitive() &&
#ifndef QT_NO_REGEXP_WILDCARD
priv->wc == rx.priv->wc &&
#endif
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 search() 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->pattern.isEmpty();
}
/*!
Returns TRUE if the regular expression is valid; otherwise returns
FALSE. An invalid regular expression never matches.
The pattern <b>[a-z</b> 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 <b>*.html</b> is a valid
wildcard regexp but an invalid full regexp.
\sa errorString()
*/
bool QRegExp::isValid() const
{
return eng->isValid();
}
/*!
Returns the pattern string of the regular expression. The pattern
has either regular expression syntax or wildcard syntax, depending
on wildcard().
\sa setPattern()
*/
QString QRegExp::pattern() const
{
return priv->pattern;
}
/*!
Sets the pattern string to \a pattern. The case sensitivity,
wildcard and minimal matching options are not changed.
\sa pattern()
*/
void QRegExp::setPattern( const QString& pattern )
{
if ( priv->pattern != pattern ) {
priv->pattern = pattern;
compile( caseSensitive() );
}
}
/*!
Returns TRUE if case sensitivity is enabled; otherwise returns
FALSE. The default is TRUE.
\sa setCaseSensitive()
*/
bool QRegExp::caseSensitive() const
{
return eng->caseSensitive();
}
/*!
Sets case sensitive matching to \a sensitive.
If \a sensitive is TRUE, <b>\\.txt$</b> matches \c{readme.txt} but
not \c{README.TXT}.
\sa caseSensitive()
*/
void QRegExp::setCaseSensitive( bool sensitive )
{
if ( sensitive != eng->caseSensitive() )
compile( sensitive );
}
#ifndef QT_NO_REGEXP_WILDCARD
/*!
Returns TRUE if wildcard mode is enabled; otherwise returns FALSE.
The default is FALSE.
\sa setWildcard()
*/
bool QRegExp::wildcard() const
{
return priv->wc;
}
/*!
Sets the wildcard mode for the regular expression. The default is
FALSE.
Setting \a wildcard to TRUE enables simple shell-like wildcard
matching. (See \link #wildcard-matching wildcard matching
(globbing) \endlink.)
For example, <b>r*.txt</b> matches the string \c{readme.txt} in
wildcard mode, but does not match \c{readme}.
\sa wildcard()
*/
void QRegExp::setWildcard( bool wildcard )
{
if ( wildcard != priv->wc ) {
priv->wc = wildcard;
compile( caseSensitive() );
}
}
#endif
/*!
Returns TRUE if minimal (non-greedy) matching is enabled;
otherwise returns FALSE.
\sa setMinimal()
*/
bool QRegExp::minimal() 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
\<b>bold\</b>, very \<b>bold\</b>!" and the pattern
<b>\<b>.*\</b></b>. With the default greedy (maximal) matching,
the match is "We must be <u>\<b>bold\</b>, very
\<b>bold\</b></u>!". But with minimal (non-greedy) matching the
first match is: "We must be <u>\<b>bold\</b></u>, very
\<b>bold\</b>!" and the second match is "We must be \<b>bold\</b>,
very <u>\<b>bold\</b></u>!". In practice we might use the pattern
<b>\<b>[^\<]+\</b></b> instead, although this will still fail for
nested tags.
\sa minimal()
*/
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
search("^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 <b>blue</b>, 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 search() searchRev() QRegExpValidator
*/
bool QRegExp::exactMatch( const QString& str ) const
{
#ifndef QT_NO_REGEXP_CAPTURE
priv->t = str;
priv->capturedCache.clear();
#endif
priv->captured = eng->match( str, 0, priv->min, TRUE, 0 );
if ( priv->captured[1] == (int) str.length() ) {
return TRUE;
} else {
priv->captured.detach();
priv->captured[0] = 0;
priv->captured[1] = eng->matchedLength();
return FALSE;
}
}
#ifndef QT_NO_COMPAT
/*! \obsolete
Attempts to match in \a str, starting from position \a index.
Returns the position of the match, or -1 if there was no match.
The length of the match is stored in \a *len, unless \a len is a
null pointer.
If \a indexIsStart is TRUE (the default), the position \a index in
the string will match the start of string anchor, <b>^</b>, in the
regexp, if present. Otherwise, position 0 in \a str will match.
Use search() and matchedLength() instead of this function.
\sa QString::mid() QConstString
*/
int QRegExp::match( const QString& str, int index, int *len,
bool indexIsStart ) const
{
int pos = search( str, index, indexIsStart ? CaretAtOffset : CaretAtZero );
if ( len != 0 )
*len = matchedLength();
return pos;
}
#endif // QT_NO_COMPAT
int QRegExp::search( const QString& str, int offset ) const
{
return search( str, offset, CaretAtZero );
}
/*!
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 <b>^</b>
should match at index 0 or at \a offset.
You might prefer to use QString::find(), QString::contains() or
even QStringList::grep(). 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.search(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().
\sa searchRev() exactMatch()
*/
int QRegExp::search( const QString& str, int offset, CaretMode caretMode ) const
{
if ( offset < 0 )
offset += str.length();
#ifndef QT_NO_REGEXP_CAPTURE
priv->t = str;
priv->capturedCache.clear();
#endif
priv->captured = eng->match( str, offset, priv->min, FALSE,
caretIndex(offset, caretMode) );
return priv->captured[0];
}
int QRegExp::searchRev( const QString& str, int offset ) const
{
return searchRev( str, offset, CaretAtZero );
}
/*!
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 <b>^</b>
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 search() exactMatch()
*/
int QRegExp::searchRev( const QString& str, int offset,
CaretMode caretMode ) const
{
if ( offset < 0 )
offset += str.length();
#ifndef QT_NO_REGEXP_CAPTURE
priv->t = str;
priv->capturedCache.clear();
#endif
if ( offset < 0 || offset > (int) str.length() ) {
priv->captured.detach();
priv->captured.fill( -1 );
return -1;
}
while ( offset >= 0 ) {
priv->captured = eng->match( str, offset, priv->min, TRUE,
caretIndex(offset, caretMode) );
if ( priv->captured[0] == offset )
return offset;
offset--;
}
return -1;
}
/*!
Returns the length of the last matched string, or -1 if there was
no match.
\sa exactMatch() search() searchRev()
*/
int QRegExp::matchedLength() const
{
return priv->captured[1];
}
#ifndef QT_NO_REGEXP_CAPTURE
/*!
Returns the number of captures contained in the regular expression.
*/
int QRegExp::numCaptures() const
{
return 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.search( "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.search( "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 <b>(\\d+)+</b>, we would hope to get a list of
all the numbers matched. However, after calling
\c{rx.search(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 \link
#cap_in_a_loop loop \endlink.
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() exactMatch() search() searchRev()
*/
QStringList QRegExp::capturedTexts()
{
if ( priv->capturedCache.isEmpty() ) {
for ( int i = 0; i < (int) priv->captured.size(); i += 2 ) {
QString m;
if ( priv->captured[i + 1] == 0 )
m = QString::fromLatin1( "" );
else if ( priv->captured[i] >= 0 )
m = priv->t.mid( priv->captured[i],
priv->captured[i + 1] );
priv->capturedCache.append( m );
}
priv->t = QString::null;
}
return priv->capturedCache;
}
/*!
Returns the text captured by the \a nth subexpression. The entire
match has index 0 and the parenthesized subexpressions have
indices starting from 1 (excluding non-capturing parentheses).
\code
QRegExp rxlen( "(\\d+)(?:\\s*)(cm|inch)" );
int pos = rxlen.search( "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.
\target cap_in_a_loop
Some patterns may lead to a number of matches which cannot be
determined in advance, for example:
\code
QRegExp rx( "(\\d+)" );
str = "Offsets: 12 14 99 231 7";
QStringList list;
pos = 0;
while ( pos >= 0 ) {
pos = rx.search( str, pos );
if ( pos > -1 ) {
list += rx.cap( 1 );
pos += rx.matchedLength();
}
}
// list contains "12", "14", "99", "231", "7"
\endcode
\sa capturedTexts() pos() exactMatch() search() searchRev()
*/
QString QRegExp::cap( int nth )
{
if ( nth < 0 || nth >= (int) priv->captured.size() / 2 )
return QString::null;
else
return capturedTexts()[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.search( "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
due to an implementation tradeoff.
\sa capturedTexts() exactMatch() search() searchRev()
*/
int QRegExp::pos( int nth )
{
if ( nth < 0 || nth >= (int) priv->captured.size() / 2 )
return -1;
else
return priv->captured[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( RXERR_OK );
} else {
return eng->errorString();
}
}
#endif
/*!
Returns the string \a str with every regexp special character
escaped with a backslash. The special characters are $, (, ), *, +,
., ?, [, \, ], ^, {, | and }.
Example:
\code
s1 = QRegExp::escape( "bingo" ); // s1 == "bingo"
s2 = QRegExp::escape( "f(x)" ); // s2 == "f\\(x\\)"
\endcode
This function is useful to construct regexp patterns dynamically:
\code
QRegExp rx( "(" + QRegExp::escape(name) +
"|" + QRegExp::escape(alias) + ")" );
\endcode
*/
QString QRegExp::escape( const QString& str )
{
static const char meta[] = "$()*+.?[\\]^{|}";
QString quoted = str;
int i = 0;
while ( i < (int) quoted.length() ) {
if ( strchr(meta, quoted[i].latin1()) != 0 )
quoted.insert( i++, "\\" );
i++;
}
return quoted;
}
void QRegExp::compile( bool caseSensitive )
{
derefEngine( eng, priv->rxpattern );
#ifndef QT_NO_REGEXP_WILDCARD
if ( priv->wc )
priv->rxpattern = wc2rx( priv->pattern );
else
#endif
priv->rxpattern = priv->pattern.isNull() ? QString::fromLatin1( "" )
: priv->pattern;
eng = newEngine( priv->rxpattern, caseSensitive );
#ifndef QT_NO_REGEXP_CAPTURE
priv->t = QString();
priv->capturedCache.clear();
#endif
priv->captured.detach();
priv->captured.fill( -1, 2 + 2 * eng->numCaptures() );
}
int QRegExp::caretIndex( int offset, CaretMode caretMode )
{
if ( caretMode == CaretAtZero ) {
return 0;
} else if ( caretMode == CaretAtOffset ) {
return offset;
} else { // CaretWontMatch
return -1;
}
}
#endif // QT_NO_REGEXP