lyx_mirror/src/Lexer.h
André Pönitz fad47c0fe0 boost/utility -> boost/noncopyable
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@20608 a592a061-630c-0410-9148-cb99ea01b6c8
2007-09-30 15:47:00 +00:00

217 lines
5.1 KiB
C++

// -*- C++ -*-
/**
* \file Lexer.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Alejandro Aguilar Sierra
* \author Lars Gullik Bjønnes
*
* Full author contact details are available in file CREDITS.
*/
// Generalized simple lexical analizer.
// It can be used for simple syntax parsers, like lyxrc,
// texclass and others to come.
#ifndef LEXER_H
#define LEXER_H
#include "support/docstring.h"
#include <boost/noncopyable.hpp>
#include <iosfwd>
namespace lyx {
namespace support { class FileName; }
///
struct keyword_item {
///
char const * tag;
///
int code;
};
/** Generalized simple lexical analizer.
Use the method isOK() to check if there is still data available
for lexing. Use one of the the operators void* or ! to test if
the last reading operation was successful.
Example:
int readParam(LyxLex &lex) {
int param = 1; // default value
if (lex.isOK()) { // the lexer has data to read
int p; // temporary variable
lex >> p;
if (lex) param = p; // only use the input if reading was successful
}
return param;
}
@see LyXRC.cpp for an example of usage.
*/
class Lexer : boost::noncopyable {
public:
///
Lexer(keyword_item *, int);
///
~Lexer();
/// Lex basic codes
enum {
///
LEX_UNDEF = -1,
///
LEX_FEOF = -2,
///
LEX_DATA = -3,
///
LEX_TOKEN = -4
};
/// stream is open and end of stream is not reached
/// FIXME: test also if pushTok is not empty
/// FIXME: the method should be renamed to something like
/// dataAvailable(), in order to reflect the real behavior
bool isOK() const;
/// FIXME: The next two operators should be replaced by one method
/// called e.g. lastReadOk(), in order to reflect the real
/// behavior
/// last read operation was successful.
operator void const *() const;
/// last read operation was not successful
bool operator!() const;
/// return true if able to open file, else false
bool setFile(support::FileName const & filename);
///
void setStream(std::istream & is);
///
std::istream & getStream();
/// Danger! Don't use it unless you know what you are doing.
void setLineNo(int l);
/// Change the character that begins a comment. Default is '#'
void setCommentChar(char c);
/// returns a lex code
int lex();
/** Just read the next word. If esc is true remember that
some chars might be escaped: "\ atleast
*/
bool next(bool esc = false);
/** Read next token. This one is almost the same as next,
but it will consider " as a regular character and always
split a word if it contains a backslash.
*/
bool nextToken();
/// Push a token, that next token got from lyxlex.
void pushToken(std::string const &);
///
int getLineNo() const;
///
int getInteger() const;
///
bool getBool() const;
///
double getFloat() const;
///
std::string const getString() const;
///
docstring const getDocString() const;
/** Get a long string, ended by the tag `endtag'.
This string can span several lines. The first line
serves as a template for how many spaces the lines
are indented. This much white space is skipped from
each following line. This mechanism does not work
perfectly if you use tabs.
*/
std::string const getLongString(std::string const & endtag);
///
bool eatLine();
/// Pushes a token list on a stack and replaces it with a new one.
void pushTable(keyword_item *, int);
/** Pops a token list into void and replaces it with the one now
on top of the stack.
*/
void popTable();
/** Prints an error message with the corresponding line number
and file name. If message contains the substring `$$Token',
it is replaced with the value of GetString()
*/
void printError(std::string const & message) const;
/// Prints the current token table on the supplied ostream.
void printTable(std::ostream &);
/// extract string
Lexer & operator>>(std::string &);
/// extract docstring
Lexer & operator>>(docstring &);
/// extract double
Lexer & operator>>(double &);
/// extract integer
Lexer & operator>>(int &);
/// extract unsigned integer
Lexer & operator>>(unsigned int &);
/// extract bool
Lexer & operator>>(bool &);
/// Quotes a string so that reading it again with Lexer::next(true)
/// gets the original string
static std::string const quoteString(std::string const &);
private:
class Pimpl;
///
Pimpl * pimpl_;
///
mutable bool lastReadOk_;
};
/** Use to enable multiple exit points.
This is needed to ensure that the pop is done upon exit from methods
with more than one exit point or that can return as a response to
exceptions.
@author Lgb
*/
class PushPopHelper {
public:
///
PushPopHelper(Lexer & lexrc, keyword_item * i, int s) : lex(lexrc) {
lex.pushTable(i, s);
}
///
~PushPopHelper() {
lex.popTable();
}
///
Lexer & lex;
};
/** Avoid wrong usage of PushPopHelper.
To avoid wrong usage:
PushPopHelper(...); // wrong
PushPopHelper pph(...); // right
*/
#define PushPopHelper(x, y, z) unnamed_PushPopHelper;
// Tip gotten from Bobby Schmidt's column in C/C++ Users Journal
} // namespace lyx
#endif