include/GTL/gml_scanner.h

0001 /* This software is distributed under the GNU Lesser General Public License */
0002 //==========================================================================
0003 //
0004 //   gml_scanner.h
0005 //
0006 //==========================================================================
0007 // $Id: gml_scanner.h,v 1.11 2000/03/06 15:16:52 raitner Exp $
0008
0009 #ifndef GTL_GML_SCANNER_H
0010 #define GTL_GML_SCANNER_H
0011
0012 #include <GTL/GTL.h>
0013
0014 #include <cstdio>
0015
0016 __GTL_BEGIN_NAMESPACE
0017
0018 /*
0019  * start-size of buffers for reading strings. If too small it will be enlarged
0020  * dynamically
0021  */
0022
0023 #define INITIAL_SIZE 1024
0024
0025 GTL_EXTERN typedef enum {
0026     GML_KEY, GML_INT, GML_DOUBLE, GML_STRING, GML_L_BRACKET,
0027     GML_R_BRACKET, GML_END, GML_LIST, GML_ERROR
0028 } GML_value;
0029
0030
0031 /**
0032  * Possible errors while parsing a GML file.
0033  */
0034 GTL_EXTERN typedef enum {
0035     GML_UNEXPECTED, GML_SYNTAX, GML_PREMATURE_EOF, GML_TOO_MANY_DIGITS,
0036     GML_OPEN_BRACKET, GML_TOO_MANY_BRACKETS, GML_OK, GML_FILE_NOT_FOUND
0037 } GML_error_value;
0038
0039
0040 /**
0041  * @short Reason and position of an error in a GML file.
0042  *
0043  * When an error occurs while parsing the structure of a GML file
0044  * <code>GML_error</code> is used to return the type and position
0045  * of the error detected. Position is specified by
0046  * <code>line</code> and <code>column</code>, but might be
0047  * somewhat imprecise. However at least the line number should
0048  * not differ too much from the real position.
0049  *
0050  * @see graph#load
0051  */
0052 struct GTL_EXTERN GML_error {
0053     /**
0054      * Contains the error description as symbolic constant:
0055      * <ul>
0056      *   <li><code>GML_FILE_NOT_FOUND</code>: A file with that name
0057      *       doesn't exist.</li>
0058      *   <li><code>GML_OK</code>: No error :-)</li>
0059      *   <li><code>GML_TOO_MANY_BRACKETS</code>: A mismatch of
0060      *       brackets was detected, i.e. there were too many closing
0061      *       brackets (<code>]</code>).</li>
0062      *   <li><code>GML_OPEN_BRACKET</code>: Now, there were too many
0063      *       opening brackets (<code>[</code>)</li>
0064      *   <li><code>GML_TOO_MANY_DIGITS</code>: The number of digits a
0065      *       integer or floating point value can have is limited to
0066      *       1024, this should be enough :-)</li>
0067      *   <li><code>GML_PREMATURE_EOF</code>: An EOF occured, where it
0068      *       wasn't expected, e.g. while scanning a string.</li>
0069      *   <li><code>GML_SYNTAX</code>: The file isn't a valid GML file,
0070      *       e.g. a mismatch in the key-value pairs.</li>
0071      *   <li><code>GML_UNEXPECTED</code>: A character occured, where
0072      *       it makes no sense, e.g. non-numerical characters in
0073      *       numbers or keys beginning with numbers</li>
0074      * </ul>
0075      *
0076      */
0077     GML_error_value err_num;
0078
0079     /**
0080      * Contains the line, where the error was detected. This will
0081      * usually be near the line where the error really is
0082      * located.
0083      */
0084     int line;
0085
0086     /**
0087      * Contains the column, where the error was detected.
0088      */
0089     int column;
0090 };
0091
0092
0093 union GTL_EXTERN GML_tok_val {
0094     long integer;
0095     double floating;
0096     char* str;
0097     struct GML_error err;
0098 };
0099
0100 /**
0101  * @internal
0102  */
0103 struct GTL_EXTERN GML_token {
0104     GML_value kind;
0105     union GML_tok_val value;
0106 };
0107
0108 /*
0109  * global variables
0110  */
0111
0112 GTL_EXTERN extern unsigned int GML_line;
0113 GTL_EXTERN extern unsigned int GML_column;
0114
0115 /*
0116  * if you are interested in the position where an error occured it is a good
0117  * idea to set GML_line and GML_column back.
0118  * This is what GML_init does.
0119  */
0120
0121 GTL_EXTERN void GML_init ();
0122
0123 /*
0124  * returns the next token in file. If an error occured it will be stored in
0125  * GML_token.
0126  */
0127
0128 GTL_EXTERN struct GML_token GML_scanner (FILE*);
0129
0130 GTL_EXTERN extern const char* GML_table[];
0131
0132 __GTL_END_NAMESPACE
0133
0134 #endif // GTL_GML_SCANNER_H
0135
0136 //--------------------------------------------------------------------------
0137 //   end of file
0138 //--------------------------------------------------------------------------