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CMake/Source/cmRegularExpression.h

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/*=========================================================================
Program: CMake - Cross-Platform Makefile Generator
Module: $RCSfile$
Language: C++
Date: $Date$
Version: $Revision$
Copyright (c) 2002 Kitware, Inc., Insight Consortium. All rights reserved.
See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
// Original Copyright notice:
// Copyright (C) 1991 Texas Instruments Incorporated.
//
// Permission is granted to any individual or institution to use, copy, modify,
// and distribute this software, provided that this complete copyright and
// permission notice is maintained, intact, in all copies and supporting
// documentation.
//
// Texas Instruments Incorporated provides this software "as is" without
// express or implied warranty.
//
// Created: MNF 06/13/89 Initial Design and Implementation
// Updated: LGO 08/09/89 Inherit from Generic
// Updated: MBN 09/07/89 Added conditional exception handling
// Updated: MBN 12/15/89 Sprinkled "const" qualifiers all over the place!
// Updated: DLS 03/22/91 New lite version
//
#ifndef cmRegularExpression_h
#define cmRegularExpression_h
#include "cmStandardIncludes.h"
const int NSUBEXP = 10;
/** \class cmRegularExpression
* \brief Implements pattern matching with regular expressions.
*
* This is the header file for the regular expression class. An object of
* this class contains a regular expression, in a special "compiled" format.
* This compiled format consists of several slots all kept as the objects
* private data. The cmRegularExpression class provides a convenient way to
* represent regular expressions. It makes it easy to search for the same
* regular expression in many different strings without having to compile a
* string to regular expression format more than necessary.
*
* This class implements pattern matching via regular expressions.
* A regular expression allows a programmer to specify complex
* patterns that can be searched for and matched against the
* character string of a string object. In its simplest form, a
* regular expression is a sequence of characters used to
* search for exact character matches. However, many times the
* exact sequence to be found is not known, or only a match at
* the beginning or end of a string is desired. The cmRegularExpression regu-
* lar expression class implements regular expression pattern
* matching as is found and implemented in many UNIX commands
* and utilities.
*
* Example: The perl code
*
* $filename =~ m"([a-z]+)\.cc";
* print $1;
*
* Is written as follows in C++
*
* cmRegularExpression re("([a-z]+)\\.cc");
* re.find(filename);
* cerr << re.match(1);
*
*
* The regular expression class provides a convenient mechanism
* for specifying and manipulating regular expressions. The
* regular expression object allows specification of such pat-
* terns by using the following regular expression metacharac-
* ters:
*
* ^ Matches at beginning of a line
*
* $ Matches at end of a line
*
* . Matches any single character
*
* [ ] Matches any character(s) inside the brackets
*
* [^ ] Matches any character(s) not inside the brackets
*
* - Matches any character in range on either side of a dash
*
* * Matches preceding pattern zero or more times
*
* + Matches preceding pattern one or more times
*
* ? Matches preceding pattern zero or once only
*
* () Saves a matched expression and uses it in a later match
*
* Note that more than one of these metacharacters can be used
* in a single regular expression in order to create complex
* search patterns. For example, the pattern [^ab1-9] says to
* match any character sequence that does not begin with the
* characters "ab" followed by numbers in the series one
* through nine.
*
* There are three constructors for cmRegularExpression. One just creates an
* empty cmRegularExpression object. Another creates a cmRegularExpression
* object and initializes it with a regular expression that is given in the
* form of a char*. The third takes a reference to a cmRegularExpression
* object as an argument and creates an object initialized with the
* information from the given cmRegularExpression object.
*
* The find member function finds the first occurence of the regualr
* expression of that object in the string given to find as an argument. Find
* returns a boolean, and if true, mutates the private data appropriately.
* Find sets pointers to the beginning and end of the thing last found, they
* are pointers into the actual string that was searched. The start and end
* member functions return indicies into the searched string that correspond
* to the beginning and end pointers respectively. The compile member
* function takes a char* and puts the compiled version of the char* argument
* into the object's private data fields. The == and != operators only check
* the to see if the compiled regular expression is the same, and the
* deep_equal functions also checks to see if the start and end pointers are
* the same. The is_valid function returns false if program is set to NULL,
* (i.e. there is no valid compiled exression). The set_invalid function sets
* the program to NULL (Warning: this deletes the compiled expression). The
* following examples may help clarify regular expression usage:
*
* * The regular expression "^hello" matches a "hello" only at the
* beginning of a line. It would match "hello there" but not "hi,
* hello there".
*
* * The regular expression "long$" matches a "long" only at the end
* of a line. It would match "so long\0", but not "long ago".
*
* * The regular expression "t..t..g" will match anything that has a
* "t" then any two characters, another "t", any two characters and
* then a "g". It will match "testing", or "test again" but would
* not match "toasting"
*
* * The regular expression "[1-9ab]" matches any number one through
* nine, and the characters "a" and "b". It would match "hello 1"
* or "begin", but would not match "no-match".
*
* * The regular expression "[^1-9ab]" matches any character that is
* not a number one through nine, or an "a" or "b". It would NOT
* match "hello 1" or "begin", but would match "no-match".
*
* * The regular expression "br* " matches something that begins with
* a "b", is followed by zero or more "r"s, and ends in a space. It
* would match "brrrrr ", and "b ", but would not match "brrh ".
*
* * The regular expression "br+ " matches something that begins with
* a "b", is followed by one or more "r"s, and ends in a space. It
* would match "brrrrr ", and "br ", but would not match "b " or
* "brrh ".
*
* * The regular expression "br? " matches something that begins with
* a "b", is followed by zero or one "r"s, and ends in a space. It
* would match "br ", and "b ", but would not match "brrrr " or
* "brrh ".
*
* * The regular expression "(..p)b" matches something ending with pb
* and beginning with whatever the two characters before the first p
* encounterd in the line were. It would find "repb" in "rep drepa
* qrepb". The regular expression "(..p)a" would find "repa qrepb"
* in "rep drepa qrepb"
*
* * The regular expression "d(..p)" matches something ending with p,
* beginning with d, and having two characters in between that are
* the same as the two characters before the first p encounterd in
* the line. It would match "drepa qrepb" in "rep drepa qrepb".
*
*/
class cmRegularExpression
{
public:
/**
* Instantiate cmRegularExpression with program=NULL.
*/
inline cmRegularExpression ();
/**
* Instantiate cmRegularExpression with compiled char*.
*/
inline cmRegularExpression (char const*);
/**
* Instantiate cmRegularExpression as a copy of another regular expression.
*/
cmRegularExpression (cmRegularExpression const&);
/**
* Destructor.
*/
inline ~cmRegularExpression();
/**
* Compile a regular expression into internal code
* for later pattern matching.
*/
bool compile (char const*);
/**
* Matches the regular expression to the given string.
* Returns true if found, and sets start and end indexes accordingly.
*/
bool find (char const*);
/**
* Matches the regular expression to the given std string.
* Returns true if found, and sets start and end indexes accordingly.
*/
bool find (std::string const&);
/**
* Index to start of first find.
*/
inline std::string::size_type start() const;
/**
* Index to end of first find.
*/
inline std::string::size_type end() const;
/**
* Returns true if two regular expressions have the same
* compiled program for pattern matching.
*/
bool operator== (cmRegularExpression const&) const;
/**
* Returns true if two regular expressions have different
* compiled program for pattern matching.
*/
inline bool operator!= (cmRegularExpression const&) const;
/**
* Returns true if have the same compiled regular expressions
* and the same start and end pointers.
*/
bool deep_equal (cmRegularExpression const&) const;
/**
* True if the compiled regexp is valid.
*/
inline bool is_valid() const;
/**
* Marks the regular expression as invalid.
*/
inline void set_invalid();
/**
* Destructor.
*/
// awf added
std::string::size_type start(int n) const;
std::string::size_type end(int n) const;
std::string match(int n) const;
private:
const char* startp[NSUBEXP];
const char* endp[NSUBEXP];
char regstart; // Internal use only
char reganch; // Internal use only
const char* regmust; // Internal use only
int regmlen; // Internal use only
char* program;
int progsize;
const char* searchstring;
};
/**
* Create an empty regular expression.
*/
inline cmRegularExpression::cmRegularExpression ()
{
this->program = 0;
}
/**
* Creates a regular expression from string s, and
* compiles s.
*/
inline cmRegularExpression::cmRegularExpression (const char* s)
{
this->program = 0;
if ( s )
{
this->compile(s);
}
}
/**
* Destroys and frees space allocated for the regular expression.
*/
inline cmRegularExpression::~cmRegularExpression ()
{
//#ifndef WIN32
delete [] this->program;
//#endif
}
/**
* Set the start position for the regular expression.
*/
inline std::string::size_type cmRegularExpression::start () const
{
return(this->startp[0] - searchstring);
}
/**
* Returns the start/end index of the last item found.
*/
inline std::string::size_type cmRegularExpression::end () const
{
return(this->endp[0] - searchstring);
}
/**
* Returns true if two regular expressions have different
* compiled program for pattern matching.
*/
inline bool cmRegularExpression::operator!= (const cmRegularExpression& r) const
{
return(!(*this == r));
}
/**
* Returns true if a valid regular expression is compiled
* and ready for pattern matching.
*/
inline bool cmRegularExpression::is_valid () const
{
return (this->program != 0);
}
inline void cmRegularExpression::set_invalid ()
{
//#ifndef WIN32
delete [] this->program;
//#endif
this->program = 0;
}
/**
* Return start index of nth submatch. start(0) is the start of the full match.
*/
inline std::string::size_type cmRegularExpression::start(int n) const
{
return this->startp[n] - searchstring;
}
/**
* Return end index of nth submatch. end(0) is the end of the full match.
*/
inline std::string::size_type cmRegularExpression::end(int n) const
{
return this->endp[n] - searchstring;
}
/**
* Return nth submatch as a string.
*/
inline std::string cmRegularExpression::match(int n) const
{
return std::string(this->startp[n], this->endp[n] - this->startp[n]);
}
#endif // cmRegularExpressionh
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