CMake/Source/cmRegularExpression.h
2001-04-27 08:01:17 -04:00

400 lines
13 KiB
C++

/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile$
Language: C++
Date: $Date$
Version: $Revision$
Copyright (c) 2001 Insight Consortium
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.
* The name of the Insight Consortium, nor the names of any consortium members,
nor of any contributors, may be used to endorse or promote products derived
from this software without specific prior written permission.
* Modified source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER 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 AUTHORS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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=========================================================================*/
// 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.
*/
void 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 long start() const;
/**
* Index to end of first find.
*/
inline long 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
int start(int n) const;
int 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 = NULL;
}
/**
* Creates a regular expression from string s, and
* compiles s.
*/
inline cmRegularExpression::cmRegularExpression (const char* s)
{
this->program = NULL;
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 long cmRegularExpression::start () const
{
return(this->startp[0] - searchstring);
}
/**
* Returns the start/end index of the last item found.
*/
inline long 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 != NULL);
}
inline void cmRegularExpression::set_invalid ()
{
//#ifndef WIN32
delete [] this->program;
//#endif
this->program = NULL;
}
/**
* Return start index of nth submatch. start(0) is the start of the full match.
*/
inline int 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 int 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