regExpPosix.H

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    Copyright (C) 2017-2021 OpenCFD Ltd.
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License
    This file is part of OpenFOAM.
 
    OpenFOAM is free software: you can redistribute it and/or modify it
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    the Free Software Foundation, either version 3 of the License, or
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    You should have received a copy of the GNU General Public License
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Class
    Foam::regExpPosix
 
Description
    Wrapper around POSIX extended regular expressions
    with some additional prefix-handling. The prefix-handling is
    loosely oriented on PCRE regular expressions and provides a
    simple means of tuning the expressions.
 
    The prefixes are detected as \c (?...) at the beginning of
    the regular expression. Any unknown/unsupported prefixes are silently
    ignored.
 
    - "(?!i)" :
       one or more embedded pattern-match modifiers for the entire pattern.
    - the \c 'i' indicates ignore-case
    - the \c '!' (exclamation) indicates negated (inverted) matching
    .
 
SeeAlso
    The manpage regex(7) for more information about POSIX regular expressions.
    These differ somewhat from \c Perl and \c sed regular expressions.
 
SeeAlso
    Foam::regExp and Foam::regExpCxx
 
Warning
    This class should not be used directly.
    Use the Foam::regExp typedef instead.
 
\deprecated
    This class will be superseded by Foam::regExpCxx as compiler support
    for regular expressions continues to improve.
 
SourceFiles
    regExpPosix.C
    regExpPosixI.H
 
\*---------------------------------------------------------------------------*/
 
#ifndef Foam_regExpPosix_H
#define Foam_regExpPosix_H
 
#include "regExpCxx.H"
#include <regex.h>
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
// Forward Declarations
template<class StringType> class SubStrings;
 
/*---------------------------------------------------------------------------*\
                         Class regExpPosix Declaration
\*---------------------------------------------------------------------------*/
 
class regExpPosix
{
    // Data Types
 
        //- Simple control types
        enum ctrlType { EMPTY = 0, NORMAL = 1, NEGATED = 2 };
 
 
    // Private Data
 
        //- Compiled regular expression
        regex_t* preg_;
 
        //- Track if input pattern is non-empty, negated etc.
        unsigned char ctrl_;
 
 
    // Private Member Functions
 
        //- Assign pattern
        bool set_pattern(const char* pattern, size_t len, bool ignoreCase);
 
 
public:
 
    // Public Types
 
        //- Type for matches - similar to std::smatch
        typedef SubStrings<std::string> results_type;
 
 
    // Static Member Data
 
        //- Grammar (unused) - for compatibility with Foam::regExpCxx
        static int grammar;
 
 
    // Static Member Functions
 
        //- Test if character is a regex meta-character
        inline static bool is_meta(const char c) noexcept
        {
            return regExpCxx::is_meta(c);
        }
 
        //- Test if string contains any (unquoted) meta-characters
        inline static bool is_meta
        (
            const std::string& str,
            const char quote = '\\'
        )
        {
            return regExpCxx::is_meta(str, quote);
        }
 
 
    // Public Classes
 
        //- Functor wrapper for testing meta-characters
        using meta = regExpCxx::meta;
 
 
    // Constructors
 
        //- Default construct
        inline regExpPosix() noexcept;
 
        //- Copy construct - disallowed
        regExpPosix(const regExpPosix&) = delete;
 
        //- Move construct
        inline regExpPosix(regExpPosix&& rgx) noexcept;
 
        //- Construct from character array, optionally ignore case
        inline explicit regExpPosix
        (
            const char* pattern,
            const bool ignoreCase = false
        );
 
        //- Construct from string, optionally ignore case
        inline explicit regExpPosix
        (
            const std::string& pattern,
            const bool ignoreCase = false
        );
 
 
    //- Destructor
    inline ~regExpPosix();
 
 
    // Member Functions
 
    // Access
 
        //- Return true if a precompiled expression does not exist
        inline bool empty() const noexcept;
 
        //- Return true if a precompiled expression exists
        inline bool exists() const noexcept;
 
        //- True if pattern matching is negated
        inline bool negated() const noexcept;
 
        //- Change pattern negation, return previous value
        inline bool negate(bool on) noexcept;
 
        //- The number of capture groups for a non-empty,
        //- non-negated expressions
        inline unsigned ngroups() const;
 
 
    // Editing
 
        //- Clear expression.
        //  \return True if expression had existed prior to the clear.
        bool clear();
 
        //- Swap contents
        inline void swap(regExpPosix& rgx);
 
        //- Compile pattern into a regular expression, optionally ignore case.
        //  \return True if the pattern was compiled
        inline bool set(const char* pattern, bool ignoreCase=false);
 
        //- Compile pattern into a regular expression, optionally ignore case.
        //  \return True if the pattern was compiled
        inline bool set(const std::string& pattern, bool ignoreCase=false);
 
 
    // Matching/Searching
 
        //- Find position within the text.
        //  \return The index where it begins or string::npos if not found
        //
        //  \note does not properly work with negated regex!
        std::string::size_type find(const std::string& text) const;
 
        //- True if the regex matches the entire text.
        //  The begin-of-line (^) and end-of-line ($) anchors are implicit
        bool match(const std::string& text) const;
 
        //- True if the regex matches the text, set the matches.
        //  The first group starts at index 1 (0 is the entire match).
        //  The begin-of-line (^) and end-of-line ($) anchors are implicit
        //
        //  \note does not properly work with negated regex!
        bool match(const std::string& text, results_type& matches) const;
 
        //- Return true if the regex was found within the text
        inline bool search(const std::string& text) const;
 
 
    // Member Operators
 
        //- Perform match on text
        inline bool operator()(const std::string& text) const;
 
        //- Copy assignment - disallowed
        void operator=(const regExpPosix&) = delete;
 
        //- Move assignment
        inline void operator=(regExpPosix&& rgx);
 
        //- Assign and compile pattern from a character array.
        //  Matching is case sensitive.
        inline void operator=(const char* pattern);
 
        //- Assign and compile pattern from string.
        //  Matching is case sensitive.
        inline void operator=(const std::string& pattern);
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#include "regExpPosixI.H"
 
#endif
 
// ************************************************************************* //