// Copyright (c) 2005, Google Inc.

 // All rights reserved.

 //

 // Redistribution and use in source and binary forms, with or without

 // modification, are permitted provided that the following conditions are

 // met:

 //

 //     * Redistributions of source code must retain the above copyright

 // notice, this list of conditions and the following disclaimer.

 //     * Redistributions in binary form must reproduce the above

 // copyright notice, this list of conditions and the following disclaimer

 // in the documentation and/or other materials provided with the

 // distribution.

 //     * Neither the name of Google Inc. nor the names of its

 // contributors may be used to endorse or promote products derived from

 // this software without specific prior written permission.

 //

 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 //

 // Author: Sanjay Ghemawat

 // Support for PCRE_XXX modifiers added by Giuseppe Maxia, July 2005

 #ifndef _PCRECPP_H

 #define _PCRECPP_H

 // C++ interface to the pcre regular-expression library.  RE supports

 // Perl-style regular expressions (with extensions like \d, \w, \s,

 // ...).

 //

 // -----------------------------------------------------------------------

 // REGEXP SYNTAX:

 //

 // This module is part of the pcre library and hence supports its syntax

 // for regular expressions.

 //

 // The syntax is pretty similar to Perl's.  For those not familiar

 // with Perl's regular expressions, here are some examples of the most

 // commonly used extensions:

 //

 //   "hello (\\w+) world"  -- \w matches a "word" character

 //   "version (\\d+)"      -- \d matches a digit

 //   "hello\\s+world"      -- \s matches any whitespace character

 //   "\\b(\\w+)\\b"        -- \b matches empty string at a word boundary

 //   "(?i)hello"           -- (?i) turns on case-insensitive matching

 //   "/\\*(.*?)\\*/"       -- .*? matches . minimum no. of times possible

 //

 // -----------------------------------------------------------------------

 // MATCHING INTERFACE:

 //

 // The "FullMatch" operation checks that supplied text matches a

 // supplied pattern exactly.

 //

 // Example: successful match

 //    pcrecpp::RE re("h.*o");

 //    re.FullMatch("hello");

 //

 // Example: unsuccessful match (requires full match):

 //    pcrecpp::RE re("e");

 //    !re.FullMatch("hello");

 //

 // Example: creating a temporary RE object:

 //    pcrecpp::RE("h.*o").FullMatch("hello");

 //

 // You can pass in a "const char*" or a "string" for "text".  The

 // examples below tend to use a const char*.

 //

 // You can, as in the different examples above, store the RE object

 // explicitly in a variable or use a temporary RE object.  The

 // examples below use one mode or the other arbitrarily.  Either

 // could correctly be used for any of these examples.

 //

 // -----------------------------------------------------------------------

 // MATCHING WITH SUB-STRING EXTRACTION:

 //

 // You can supply extra pointer arguments to extract matched subpieces.

 //

 // Example: extracts "ruby" into "s" and 1234 into "i"

 //    int i;

 //    string s;

 //    pcrecpp::RE re("(\\w+):(\\d+)");

 //    re.FullMatch("ruby:1234", &s, &i);

 //

 // Example: does not try to extract any extra sub-patterns

 //    re.FullMatch("ruby:1234", &s);

 //

 // Example: does not try to extract into NULL

 //    re.FullMatch("ruby:1234", NULL, &i);

 //

 // Example: integer overflow causes failure

 //    !re.FullMatch("ruby:1234567891234", NULL, &i);

 //

 // Example: fails because there aren't enough sub-patterns:

 //    !pcrecpp::RE("\\w+:\\d+").FullMatch("ruby:1234", &s);

 //

 // Example: fails because string cannot be stored in integer

 //    !pcrecpp::RE("(.*)").FullMatch("ruby", &i);

 //

 // The provided pointer arguments can be pointers to any scalar numeric

 // type, or one of

 //    string        (matched piece is copied to string)

 //    StringPiece   (StringPiece is mutated to point to matched piece)

 //    T             (where "bool T::ParseFrom(const char*, int)" exists)

 //    NULL          (the corresponding matched sub-pattern is not copied)

 //

 // CAVEAT: An optional sub-pattern that does not exist in the matched

 // string is assigned the empty string.  Therefore, the following will

 // return false (because the empty string is not a valid number):

 //    int number;

 //    pcrecpp::RE::FullMatch("abc", "[a-z]+(\\d+)?", &number);

 //

 // -----------------------------------------------------------------------

 // DO_MATCH

 //

 // The matching interface supports at most 16 arguments per call.

 // If you need more, consider using the more general interface

 // pcrecpp::RE::DoMatch().  See pcrecpp.h for the signature for DoMatch.

 //

 // -----------------------------------------------------------------------

 // PARTIAL MATCHES

 //

 // You can use the "PartialMatch" operation when you want the pattern

 // to match any substring of the text.

 //

 // Example: simple search for a string:

 //    pcrecpp::RE("ell").PartialMatch("hello");

 //

 // Example: find first number in a string:

 //    int number;

 //    pcrecpp::RE re("(\\d+)");

 //    re.PartialMatch("x*100 + 20", &number);

 //    assert(number == 100);

 //

 // -----------------------------------------------------------------------

 // UTF-8 AND THE MATCHING INTERFACE:

 //

 // By default, pattern and text are plain text, one byte per character.

 // The UTF8 flag, passed to the constructor, causes both pattern

 // and string to be treated as UTF-8 text, still a byte stream but

 // potentially multiple bytes per character. In practice, the text

 // is likelier to be UTF-8 than the pattern, but the match returned

 // may depend on the UTF8 flag, so always use it when matching

 // UTF8 text.  E.g., "." will match one byte normally but with UTF8

 // set may match up to three bytes of a multi-byte character.

 //

 // Example:

 //    pcrecpp::RE_Options options;

 //    options.set_utf8();

 //    pcrecpp::RE re(utf8_pattern, options);

 //    re.FullMatch(utf8_string);

 //

 // Example: using the convenience function UTF8():

 //    pcrecpp::RE re(utf8_pattern, pcrecpp::UTF8());

 //    re.FullMatch(utf8_string);

 //

 // NOTE: The UTF8 option is ignored if pcre was not configured with the

 //       --enable-utf8 flag.

 //

 // -----------------------------------------------------------------------

 // PASSING MODIFIERS TO THE REGULAR EXPRESSION ENGINE

 //

 // PCRE defines some modifiers to change the behavior of the regular

 // expression engine.

 // The C++ wrapper defines an auxiliary class, RE_Options, as a vehicle

 // to pass such modifiers to a RE class.

 //

 // Currently, the following modifiers are supported

 //

 //    modifier              description               Perl corresponding

 //

 //    PCRE_CASELESS         case insensitive match    /i

 //    PCRE_MULTILINE        multiple lines match      /m

 //    PCRE_DOTALL           dot matches newlines      /s

 //    PCRE_DOLLAR_ENDONLY   $ matches only at end     N/A

 //    PCRE_EXTRA            strict escape parsing     N/A

 //    PCRE_EXTENDED         ignore whitespaces        /x

 //    PCRE_UTF8             handles UTF8 chars        built-in

 //    PCRE_UNGREEDY         reverses * and *?         N/A

 //    PCRE_NO_AUTO_CAPTURE  disables matching parens  N/A (*)

 //

 // (For a full account on how each modifier works, please check the

 // PCRE API reference manual).

 //

 // (*) Both Perl and PCRE allow non matching parentheses by means of the

 // "?:" modifier within the pattern itself. e.g. (?:ab|cd) does not

 // capture, while (ab|cd) does.

 //

 // For each modifier, there are two member functions whose name is made

 // out of the modifier in lowercase, without the "PCRE_" prefix. For

 // instance, PCRE_CASELESS is handled by

 //    bool caseless(),

 // which returns true if the modifier is set, and

 //    RE_Options & set_caseless(bool),

 // which sets or unsets the modifier.

 //

 // Moreover, PCRE_EXTRA_MATCH_LIMIT can be accessed through the

 // set_match_limit() and match_limit() member functions.

 // Setting match_limit to a non-zero value will limit the executation of

 // pcre to keep it from doing bad things like blowing the stack or taking

 // an eternity to return a result.  A value of 5000 is good enough to stop

 // stack blowup in a 2MB thread stack.  Setting match_limit to zero will

 // disable match limiting.  Alternately, you can set match_limit_recursion()

 // which uses PCRE_EXTRA_MATCH_LIMIT_RECURSION to limit how much pcre

 // recurses.  match_limit() caps the number of matches pcre does;

 // match_limit_recrusion() caps the depth of recursion.

 //

 // Normally, to pass one or more modifiers to a RE class, you declare

 // a RE_Options object, set the appropriate options, and pass this

 // object to a RE constructor. Example:

 //

 //    RE_options opt;

 //    opt.set_caseless(true);

 //

 //    if (RE("HELLO", opt).PartialMatch("hello world")) ...

 //

 // RE_options has two constructors. The default constructor takes no

 // arguments and creates a set of flags that are off by default.

 //

 // The optional parameter 'option_flags' is to facilitate transfer

 // of legacy code from C programs.  This lets you do

 //    RE(pattern, RE_Options(PCRE_CASELESS|PCRE_MULTILINE)).PartialMatch(str);

 //

 // But new code is better off doing

 //    RE(pattern,

 //      RE_Options().set_caseless(true).set_multiline(true)).PartialMatch(str);

 // (See below)

 //

 // If you are going to pass one of the most used modifiers, there are some

 // convenience functions that return a RE_Options class with the

 // appropriate modifier already set:

 // CASELESS(), UTF8(), MULTILINE(), DOTALL(), EXTENDED()

 //

 // If you need to set several options at once, and you don't want to go

 // through the pains of declaring a RE_Options object and setting several

 // options, there is a parallel method that give you such ability on the

 // fly. You can concatenate several set_xxxxx member functions, since each

 // of them returns a reference to its class object.  e.g.: to pass

 // PCRE_CASELESS, PCRE_EXTENDED, and PCRE_MULTILINE to a RE with one

 // statement, you may write

 //

 //    RE(" ^ xyz \\s+ .* blah$", RE_Options()

 //                            .set_caseless(true)

 //                            .set_extended(true)

 //                            .set_multiline(true)).PartialMatch(sometext);

 //

 // -----------------------------------------------------------------------

 // SCANNING TEXT INCREMENTALLY

 //

 // The "Consume" operation may be useful if you want to repeatedly

 // match regular expressions at the front of a string and skip over

 // them as they match.  This requires use of the "StringPiece" type,

 // which represents a sub-range of a real string.  Like RE, StringPiece

 // is defined in the pcrecpp namespace.

 //

 // Example: read lines of the form "var = value" from a string.

 //    string contents = ...;                 // Fill string somehow

 //    pcrecpp::StringPiece input(contents);  // Wrap in a StringPiece

 //

 //    string var;

 //    int value;

 //    pcrecpp::RE re("(\\w+) = (\\d+)\n");

 //    while (re.Consume(&input, &var, &value)) {

 //      ...;

 //    }

 //

 // Each successful call to "Consume" will set "var/value", and also

 // advance "input" so it points past the matched text.

 //

 // The "FindAndConsume" operation is similar to "Consume" but does not

 // anchor your match at the beginning of the string.  For example, you

 // could extract all words from a string by repeatedly calling

 //     pcrecpp::RE("(\\w+)").FindAndConsume(&input, &word)

 //

 // -----------------------------------------------------------------------

 // PARSING HEX/OCTAL/C-RADIX NUMBERS

 //

 // By default, if you pass a pointer to a numeric value, the

 // corresponding text is interpreted as a base-10 number.  You can

 // instead wrap the pointer with a call to one of the operators Hex(),

 // Octal(), or CRadix() to interpret the text in another base.  The

 // CRadix operator interprets C-style "0" (base-8) and "0x" (base-16)

 // prefixes, but defaults to base-10.

 //

 // Example:

 //   int a, b, c, d;

 //   pcrecpp::RE re("(.*) (.*) (.*) (.*)");

 //   re.FullMatch("100 40 0100 0x40",

 //                pcrecpp::Octal(&a), pcrecpp::Hex(&b),

 //                pcrecpp::CRadix(&c), pcrecpp::CRadix(&d));

 // will leave 64 in a, b, c, and d.

 //

 // -----------------------------------------------------------------------

 // REPLACING PARTS OF STRINGS

 //

 // You can replace the first match of "pattern" in "str" with

 // "rewrite".  Within "rewrite", backslash-escaped digits (\1 to \9)

 // can be used to insert text matching corresponding parenthesized

 // group from the pattern.  \0 in "rewrite" refers to the entire

 // matching text.  E.g.,

 //

 //   string s = "yabba dabba doo";

 //   pcrecpp::RE("b+").Replace("d", &s);

 //

 // will leave "s" containing "yada dabba doo".  The result is true if

 // the pattern matches and a replacement occurs, or false otherwise.

 //

 // GlobalReplace() is like Replace(), except that it replaces all

 // occurrences of the pattern in the string with the rewrite.

 // Replacements are not subject to re-matching.  E.g.,

 //

 //   string s = "yabba dabba doo";

 //   pcrecpp::RE("b+").GlobalReplace("d", &s);

 //

 // will leave "s" containing "yada dada doo".  It returns the number

 // of replacements made.

 //

 // Extract() is like Replace(), except that if the pattern matches,

 // "rewrite" is copied into "out" (an additional argument) with

 // substitutions.  The non-matching portions of "text" are ignored.

 // Returns true iff a match occurred and the extraction happened

 // successfully.  If no match occurs, the string is left unaffected.

 #include <string>

 #include <pcre.h>

 #include <pcrecpparg.h>   // defines the Arg class

 // This isn't technically needed here, but we include it

 // anyway so folks who include pcrecpp.h don't have to.

 #include <pcre_stringpiece.h>

 namespace pcrecpp {

 #define PCRE_SET_OR_CLEAR(b, o) \

     if (b) all_options_ |= (o); else all_options_ &= ~(o); \

     return *this

 #define PCRE_IS_SET(o)  \

         (all_options_ & o) == o

 /***** Compiling regular expressions: the RE class *****/

 // RE_Options allow you to set options to be passed along to pcre,

 // along with other options we put on top of pcre.

 // Only 9 modifiers, plus match_limit and match_limit_recursion,

 // are supported now.

 class PCRECPP_EXP_DEFN RE_Options {

  public:

   // constructor

   RE_Options() : match_limit_(0), match_limit_recursion_(0), all_options_(0) {}

   // alternative constructor.

   // To facilitate transfer of legacy code from C programs

   //

   // This lets you do

   //    RE(pattern, RE_Options(PCRE_CASELESS|PCRE_MULTILINE)).PartialMatch(str);

   // But new code is better off doing

   //    RE(pattern,

   //      RE_Options().set_caseless(true).set_multiline(true)).PartialMatch(str);

   RE_Options(int option_flags) : match_limit_(0), match_limit_recursion_(0),

                                  all_options_(option_flags) {}

   // we're fine with the default destructor, copy constructor, etc.

   // accessors and mutators

   int match_limit() const { return match_limit_; };

   RE_Options &set_match_limit(int limit) {

     match_limit_ = limit;

     return *this;

   }

   int match_limit_recursion() const { return match_limit_recursion_; };

   RE_Options &set_match_limit_recursion(int limit) {

     match_limit_recursion_ = limit;

     return *this;

   }

   bool caseless() const {

     return PCRE_IS_SET(PCRE_CASELESS);

   }

   RE_Options &set_caseless(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_CASELESS);

   }

   bool multiline() const {

     return PCRE_IS_SET(PCRE_MULTILINE);

   }

   RE_Options &set_multiline(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_MULTILINE);

   }

   bool dotall() const {

     return PCRE_IS_SET(PCRE_DOTALL);

   }

   RE_Options &set_dotall(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_DOTALL);

   }

   bool extended() const {

     return PCRE_IS_SET(PCRE_EXTENDED);

   }

   RE_Options &set_extended(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_EXTENDED);

   }

   bool dollar_endonly() const {

     return PCRE_IS_SET(PCRE_DOLLAR_ENDONLY);

   }

   RE_Options &set_dollar_endonly(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_DOLLAR_ENDONLY);

   }

   bool extra() const {

     return PCRE_IS_SET(PCRE_EXTRA);

   }

   RE_Options &set_extra(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_EXTRA);

   }

   bool ungreedy() const {

     return PCRE_IS_SET(PCRE_UNGREEDY);

   }

   RE_Options &set_ungreedy(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_UNGREEDY);

   }

   bool utf8() const {

     return PCRE_IS_SET(PCRE_UTF8);

   }

   RE_Options &set_utf8(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_UTF8);

   }

   bool no_auto_capture() const {

     return PCRE_IS_SET(PCRE_NO_AUTO_CAPTURE);

   }

   RE_Options &set_no_auto_capture(bool x) {

     PCRE_SET_OR_CLEAR(x, PCRE_NO_AUTO_CAPTURE);

   }

   RE_Options &set_all_options(int opt) {

     all_options_ = opt;

     return *this;

   }

   int all_options() const {

     return all_options_ ;

   }

   // TODO: add other pcre flags

  private:

   int match_limit_;

   int match_limit_recursion_;

   int all_options_;

 };

 // These functions return some common RE_Options

 static inline RE_Options UTF8() {

   return RE_Options().set_utf8(true);

 }

 static inline RE_Options CASELESS() {

   return RE_Options().set_caseless(true);

 }

 static inline RE_Options MULTILINE() {

   return RE_Options().set_multiline(true);

 }

 static inline RE_Options DOTALL() {

   return RE_Options().set_dotall(true);

 }

 static inline RE_Options EXTENDED() {

   return RE_Options().set_extended(true);

 }

 // Interface for regular expression matching.  Also corresponds to a

 // pre-compiled regular expression.  An "RE" object is safe for

 // concurrent use by multiple threads.

 class PCRECPP_EXP_DEFN RE {

  public:

   // We provide implicit conversions from strings so that users can

   // pass in a string or a "const char*" wherever an "RE" is expected.

   RE(const string& pat) { Init(pat, NULL); }

   RE(const string& pat, const RE_Options& option) { Init(pat, &option); }

   RE(const char* pat) { Init(pat, NULL); }

   RE(const char* pat, const RE_Options& option) { Init(pat, &option); }

   RE(const unsigned char* pat) {

     Init(reinterpret_cast<const char*>(pat), NULL);

   }

   RE(const unsigned char* pat, const RE_Options& option) {

     Init(reinterpret_cast<const char*>(pat), &option);

   }

   // Copy constructor & assignment - note that these are expensive

   // because they recompile the expression.

   RE(const RE& re) { Init(re.pattern_, &re.options_); }

   const RE& operator=(const RE& re) {

     if (this != &re) {

       Cleanup();

       // This is the code that originally came from Google

       // Init(re.pattern_.c_str(), &re.options_);

       // This is the replacement from Ari Pollak

       Init(re.pattern_, &re.options_);

     }

     return *this;

   }

   ~RE();

   // The string specification for this RE.  E.g.

   //   RE re("ab*c?d+");

   //   re.pattern();    // "ab*c?d+"

   const string& pattern() const { return pattern_; }

   // If RE could not be created properly, returns an error string.

   // Else returns the empty string.

   const string& error() const { return *error_; }

   /***** The useful part: the matching interface *****/

   // This is provided so one can do pattern.ReplaceAll() just as

   // easily as ReplaceAll(pattern-text, ....)

   bool FullMatch(const StringPiece& text,

                  const Arg& ptr1 = no_arg,

                  const Arg& ptr2 = no_arg,

                  const Arg& ptr3 = no_arg,

                  const Arg& ptr4 = no_arg,

                  const Arg& ptr5 = no_arg,

                  const Arg& ptr6 = no_arg,

                  const Arg& ptr7 = no_arg,

                  const Arg& ptr8 = no_arg,

                  const Arg& ptr9 = no_arg,

                  const Arg& ptr10 = no_arg,

                  const Arg& ptr11 = no_arg,

                  const Arg& ptr12 = no_arg,

                  const Arg& ptr13 = no_arg,

                  const Arg& ptr14 = no_arg,

                  const Arg& ptr15 = no_arg,

                  const Arg& ptr16 = no_arg) const;

   bool PartialMatch(const StringPiece& text,

                     const Arg& ptr1 = no_arg,

                     const Arg& ptr2 = no_arg,

                     const Arg& ptr3 = no_arg,

                     const Arg& ptr4 = no_arg,

                     const Arg& ptr5 = no_arg,

                     const Arg& ptr6 = no_arg,

                     const Arg& ptr7 = no_arg,

                     const Arg& ptr8 = no_arg,

                     const Arg& ptr9 = no_arg,

                     const Arg& ptr10 = no_arg,

                     const Arg& ptr11 = no_arg,

                     const Arg& ptr12 = no_arg,

                     const Arg& ptr13 = no_arg,

                     const Arg& ptr14 = no_arg,

                     const Arg& ptr15 = no_arg,

                     const Arg& ptr16 = no_arg) const;

   bool Consume(StringPiece* input,

                const Arg& ptr1 = no_arg,

                const Arg& ptr2 = no_arg,

                const Arg& ptr3 = no_arg,

                const Arg& ptr4 = no_arg,

                const Arg& ptr5 = no_arg,

                const Arg& ptr6 = no_arg,

                const Arg& ptr7 = no_arg,

                const Arg& ptr8 = no_arg,

                const Arg& ptr9 = no_arg,

                const Arg& ptr10 = no_arg,

                const Arg& ptr11 = no_arg,

                const Arg& ptr12 = no_arg,

                const Arg& ptr13 = no_arg,

                const Arg& ptr14 = no_arg,

                const Arg& ptr15 = no_arg,

                const Arg& ptr16 = no_arg) const;

   bool FindAndConsume(StringPiece* input,

                       const Arg& ptr1 = no_arg,

                       const Arg& ptr2 = no_arg,

                       const Arg& ptr3 = no_arg,

                       const Arg& ptr4 = no_arg,

                       const Arg& ptr5 = no_arg,

                       const Arg& ptr6 = no_arg,

                       const Arg& ptr7 = no_arg,

                       const Arg& ptr8 = no_arg,

                       const Arg& ptr9 = no_arg,

                       const Arg& ptr10 = no_arg,

                       const Arg& ptr11 = no_arg,

                       const Arg& ptr12 = no_arg,

                       const Arg& ptr13 = no_arg,

                       const Arg& ptr14 = no_arg,

                       const Arg& ptr15 = no_arg,

                       const Arg& ptr16 = no_arg) const;

   bool Replace(const StringPiece& rewrite,

                string *str) const;

   int GlobalReplace(const StringPiece& rewrite,

                     string *str) const;

   bool Extract(const StringPiece &rewrite,

                const StringPiece &text,

                string *out) const;

   // Escapes all potentially meaningful regexp characters in

   // 'unquoted'.  The returned string, used as a regular expression,

   // will exactly match the original string.  For example,

   //           1.5-2.0?

   // may become:

   //           1\.5\-2\.0\?

   // Note QuoteMeta behaves the same as perl's QuoteMeta function,

   // *except* that it escapes the NUL character (\0) as backslash + 0,

   // rather than backslash + NUL.

   static string QuoteMeta(const StringPiece& unquoted);

   /***** Generic matching interface *****/

   // Type of match (TODO: Should be restructured as part of RE_Options)

   enum Anchor {

     UNANCHORED,         // No anchoring

     ANCHOR_START,       // Anchor at start only

     ANCHOR_BOTH         // Anchor at start and end

   };

   // General matching routine.  Stores the length of the match in

   // "*consumed" if successful.

   bool DoMatch(const StringPiece& text,

                Anchor anchor,

                int* consumed,

                const Arg* const* args, int n) const;

   // Return the number of capturing subpatterns, or -1 if the

   // regexp wasn't valid on construction.

   int NumberOfCapturingGroups() const;

   // The default value for an argument, to indicate the end of the argument

   // list. This must be used only in optional argument defaults. It should NOT

   // be passed explicitly. Some people have tried to use it like this:

   //

   //   FullMatch(x, y, &z, no_arg, &w);

   //

   // This is a mistake, and will not work.

   static Arg no_arg;

  private:

   void Init(const string& pattern, const RE_Options* options);

   void Cleanup();

   // Match against "text", filling in "vec" (up to "vecsize" * 2/3) with

   // pairs of integers for the beginning and end positions of matched

   // text.  The first pair corresponds to the entire matched text;

   // subsequent pairs correspond, in order, to parentheses-captured

   // matches.  Returns the number of pairs (one more than the number of

   // the last subpattern with a match) if matching was successful

   // and zero if the match failed.

   // I.e. for RE("(foo)|(bar)|(baz)") it will return 2, 3, and 4 when matching

   // against "foo", "bar", and "baz" respectively.

   // When matching RE("(foo)|hello") against "hello", it will return 1.

   // But the values for all subpattern are filled in into "vec".

   int TryMatch(const StringPiece& text,

                int startpos,

                Anchor anchor,

                int *vec,

                int vecsize) const;

   // Append the "rewrite" string, with backslash subsitutions from "text"

   // and "vec", to string "out".

   bool Rewrite(string *out,

                const StringPiece& rewrite,

                const StringPiece& text,

                int *vec,

                int veclen) const;

   // internal implementation for DoMatch

   bool DoMatchImpl(const StringPiece& text,

                    Anchor anchor,

                    int* consumed,

                    const Arg* const args[],

                    int n,

                    int* vec,

                    int vecsize) const;

   // Compile the regexp for the specified anchoring mode

   pcre* Compile(Anchor anchor);

   string        pattern_;

   RE_Options    options_;

   pcre*         re_full_;       // For full matches

   pcre*         re_partial_;    // For partial matches

   const string* error_;         // Error indicator (or points to empty string)

 };

 }   // namespace pcrecpp

 #endif /* _PCRECPP_H */