4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
7 * \author Alejandro Aguilar Sierra
8 * \author Lars Gullik Bjønnes
10 * Full author contact details are available in file CREDITS.
13 // Generalized simple lexical analizer.
14 // It can be used for simple syntax parsers, like lyxrc,
15 // texclass and others to come.
20 #include "support/strfwd.h"
25 namespace support
{ class FileName
; }
29 /** A helper structure to describe a keyword for the Lexer.
30 Usually used bundled in C style arrays and passed to the
31 Lexer using a LexerKeywordTable object.
35 /// the string to be recognized
37 /// a corresponding numerical id
42 /** Generalized simple lexical analizer.
43 Use the method isOK() to check if there is still data available
44 for lexing. Use one of the the operators void* or ! to test if
45 the last reading operation was successful.
49 int readParam(LyxLex & lex)
51 int param = 1; // default value
52 if (lex.isOK()) { // the lexer has data to read
53 int p; // temporary variable
56 param = p; // only use the input if reading was successful
61 @see LyXRC.cpp for an example of usage.
66 /// initialize Lexer with no special keywords.
68 /// initialize Lexer with a bunch of keywords
69 template<int N
> Lexer(LexerKeyword (&table
)[N
])
70 : pimpl_(0) { init(table
, N
); }
87 /// stream is open and end of stream is not reached
88 /// FIXME: test also if pushToken is not empty
89 /// FIXME: the method should be renamed to something like
90 /// dataAvailable(), in order to reflect the real behavior
92 /// FIXME: The next two operators should be replaced by one method
93 /// called e.g. lastReadOk(), in order to reflect the real
95 /// last read operation was successful.
96 operator void const *() const;
97 /// last read operation was not successful
98 bool operator!() const;
99 /// return true if able to open file, else false
100 bool setFile(support::FileName
const & filename
);
102 void setStream(std::istream
& is
);
104 std::istream
& getStream();
105 /// Danger! Don't use it unless you know what you are doing.
106 void setLineNumber(int l
);
107 /// Change the character that begins a comment. Default is '#'
108 void setCommentChar(char c
);
110 /// returns a lex code
113 /** Just read the next word. If esc is true remember that
114 some chars might be escaped: "\ at least
116 bool next(bool esc
= false);
118 /** Read next token. This one is almost the same as next,
119 but it will consider " as a regular character and always
120 split a word if it contains a backslash.
123 /// Push a token, that next token got from lyxlex.
124 void pushToken(std::string
const &);
126 /// return the current line number
127 int lineNumber() const;
130 int getInteger() const;
132 bool getBool() const;
134 double getFloat() const;
136 std::string
const getString() const;
139 docstring
const getDocString() const;
141 /** Get a long string, ended by the tag `endtag'.
142 This string can span several lines. The first line
143 serves as a template for how many spaces the lines
144 are indented. This much white space is skipped from
145 each following line. This mechanism does not work
146 perfectly if you use tabs.
148 std::string
const getLongString(std::string
const & endtag
);
153 /// Pushes a token list on a stack and replaces it with a new one.
154 template<int N
> void pushTable(LexerKeyword (&table
)[N
])
155 { pushTable(table
, N
); }
157 /** Pops a token list into void and replaces it with the one now
162 /** Prints an error message with the corresponding line number
163 and file name. If message contains the substring `$$Token',
164 it is replaced with the value of GetString()
166 void printError(std::string
const & message
) const;
168 /// Prints the current token table on the supplied ostream.
169 void printTable(std::ostream
&);
170 /// Used to dispaly context information in case of errors.
171 void setContext(std::string
const & functionName
);
174 Lexer
& operator>>(std::string
&);
175 /// extract docstring
176 Lexer
& operator>>(docstring
&);
178 Lexer
& operator>>(double &);
180 Lexer
& operator>>(int &);
181 /// extract unsigned integer
182 Lexer
& operator>>(unsigned int &);
184 Lexer
& operator>>(bool &);
185 /// extract first char of the string
186 Lexer
& operator>>(char &);
188 /// read and check a required token
189 Lexer
& operator>>(char const * required
);
190 /// check for an optional token and swallow it if present.
191 bool checkFor(char const * required
);
193 /// Quotes a string so that reading it again with Lexer::next(true)
194 /// gets the original string
195 static std::string
quoteString(std::string
const &);
199 Lexer(Lexer
const &);
200 void operator=(Lexer
const &);
203 friend class PushPopHelper
;
206 void init(LexerKeyword
*, int);
207 void pushTable(LexerKeyword
*, int);
214 mutable bool lastReadOk_
;
218 /// extract something constructable from a string, i.e. a LaTeX length
220 Lexer
& operator>>(Lexer
& lex
, T
& t
)
223 t
= T(lex
.getString());
228 /** Use to enable multiple exit points.
229 This is needed to ensure that the pop is done upon exit from methods
230 with more than one exit point or that can return as a response to
239 PushPopHelper(Lexer
& l
, LexerKeyword (&table
)[N
])
242 lex
.pushTable(table
, N
);
252 /** Avoid wrong usage of PushPopHelper.
253 To avoid wrong usage:
254 PushPopHelper(...); // wrong
255 PushPopHelper pph(...); // right
257 #define PushPopHelper(x, y, z) unnamed_PushPopHelper;
258 // Tip gotten from Bobby Schmidt's column in C/C++ Users Journal