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// Copyright (C) 2005 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#undef DLIB_CPP_TOKENIZER_KERNEl_ABSTRACT_
#ifdef DLIB_CPP_TOKENIZER_KERNEl_ABSTRACT_
#include <string>
#include <ioswfd>
namespace dlib
{
class cpp_tokenizer
{
/*!
INITIAL VALUE
stream_is_set() == false
WHAT THIS OBJECT REPRESENTS
This object represents a simple tokenizer for C++ source code.
BUFFERING
This object is allowed to buffer data from the input stream.
Thus if you clear it or switch streams (via calling set_stream())
any buffered data will be lost.
TOKENS
When picking out tokens the cpp_tokenizer will always extract the
longest token it can. For example, if faced with the string
"AAA" it will consider the three As to be a single IDENTIFIER
token not three smaller IDENTIFIER tokens.
Also note that no characters in the input stream are discarded.
They will all be returned in the text of some token.
Additionally, each character will never be returned more than once.
This means that if you concatenated all returned tokens it would exactly
reproduce the contents of the input stream.
The tokens are defined as follows:
END_OF_FILE
This token represents the end of file. It doesn't have any
actual characters associated with it.
KEYWORD
This token matches a C++ keyword. (This includes the preprocessor
directives).
COMMENT
This token matches a C++ comment.
SINGLE_QUOTED_TEXT
This token matches the text of any single quoted literal.
For example, 'a' would be a match and the text of this token
would be the single character a.
DOUBLE_QUOTED_TEXT
This token matches the text of any double quoted string.
For example, "C++" would be a match and the text of this token
would be the three character string C++.
WHITE_SPACE
This is a multi character token. It is defined as a sequence of
one or more spaces, carrage returns, newlines, and tabs. I.e. It
is composed of characters from the following string " \r\n\t".
IDENTIFIER
This token matches any C++ identifier that isn't matched by any
of the above tokens. (A C++ identifier being a string matching
the regular expression [_$a-zA-Z][_$a-zA-Z0-9]*).
NUMBER
This token matches any C++ numerical constant.
OTHER
This matches anything that isn't part of one of the above tokens.
It is always a single character.
!*/
public:
enum
{
END_OF_FILE,
KEYWORD,
COMMENT,
SINGLE_QUOTED_TEXT,
DOUBLE_QUOTED_TEXT,
IDENTIFIER,
OTHER,
NUMBER,
WHITE_SPACE
};
cpp_tokenizer (
);
/*!
ensures
- #*this is properly initialized
throws
- std::bad_alloc
!*/
virtual ~cpp_tokenizer (
);
/*!
ensures
- any resources associated with *this have been released
!*/
void clear(
);
/*!
ensures
- #*this has its initial value
throws
- std::bad_alloc
If this exception is thrown then #*this is unusable
until clear() is called and succeeds.
!*/
void set_stream (
std::istream& in
);
/*!
ensures
- #*this will read data from in and tokenize it
- #stream_is_set() == true
- #get_stream() == in
!*/
bool stream_is_set (
) const;
/*!
ensures
- returns true if a stream has been associated with *this by calling
set_stream()
!*/
std::istream& get_stream (
) const;
/*!
requires
- stream_is_set() == true
ensures
- returns a reference to the istream object that *this is reading
from.
!*/
void get_token (
int& type,
std::string& token
);
/*!
requires
- stream_is_set() == true
ensures
- #token == the next token from the input stream get_stream()
- #type == the type of the token in #token
throws
- bad_alloc
If this exception is thrown then the call to this function will
have no effect on *this but the values of #type and #token will be
undefined. Additionally, some characters may have been read
from the stream get_stream() and lost.
!*/
int peek_type (
) const;
/*!
requires
- stream_is_set() == true
ensures
- returns the type of the token that will be returned from
the next call to get_token()
throws
- bad_alloc
If this exception is thrown then the call to this function will
have no effect on *this. However, some characters may have been
read from the stream get_stream() and lost.
!*/
const std::string& peek_token (
) const;
/*!
requires
- stream_is_set() == true
ensures
- returns the text of the token that will be returned from
the next call to get_token()
throws
- bad_alloc
If this exception is thrown then the call to this function will
have no effect on *this. However, some characters may have been
read from the stream get_stream() and lost.
!*/
void swap (
cpp_tokenizer& item
);
/*!
ensures
- swaps *this and item
!*/
private:
// restricted functions
cpp_tokenizer(const cpp_tokenizer&); // copy constructor
cpp_tokenizer& operator=(const cpp_tokenizer&); // assignment operator
};
inline void swap (
cpp_tokenizer& a,
cpp_tokenizer& b
) { a.swap(b); }
/*!
provides a global swap function
!*/
}
#endif // DLIB_CPP_TOKENIZER_KERNEl_ABSTRACT_
|
