icu/unicode/parseerr.h

   1 /*
   2 **********************************************************************
   3 *   Copyright (C) 1999-2004, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 **********************************************************************
   6 *   Date        Name        Description
   7 *   03/14/00    aliu        Creation.
   8 *   06/27/00    aliu        Change from C++ class to C struct
   9 **********************************************************************
  10 */
  11 #ifndef PARSEERR_H
  12 #define PARSEERR_H
  13
  14 #include "unicode/utypes.h"
  15
  16
  17 /**
  18  * The capacity of the context strings in UParseError.
  19  * @stable ICU 2.0
  20  */
  21 enum { U_PARSE_CONTEXT_LEN = 16 };
  22
  23 /**
  24  * A UParseError struct is used to returned detailed information about
  25  * parsing errors.  It is used by ICU parsing engines that parse long
  26  * rules, patterns, or programs, where the text being parsed is long
  27  * enough that more information than a UErrorCode is needed to
  28  * localize the error.
  29  *
  30  * <p>The line, offset, and context fields are optional; parsing
  31  * engines may choose not to use to use them.
  32  *
  33  * <p>The preContext and postContext strings include some part of the
  34  * context surrounding the error.  If the source text is "let for=7"
  35  * and "for" is the error (e.g., because it is a reserved word), then
  36  * some examples of what a parser might produce are the following:
  37  *
  38  * <pre>
  39  * preContext   postContext
  40  * ""           ""            The parser does not support context
  41  * "let "       "=7"          Pre- and post-context only
  42  * "let "       "for=7"       Pre- and post-context and error text
  43  * ""           "for"         Error text only
  44  * </pre>
  45  *
  46  * <p>Examples of engines which use UParseError (or may use it in the
  47  * future) are Transliterator, RuleBasedBreakIterator, and
  48  * RegexPattern.
  49  *
  50  * @stable ICU 2.0
  51  */
  52 typedef struct UParseError {
  53
  54     /**
  55      * The line on which the error occured.  If the parser uses this
  56      * field, it sets it to the line number of the source text line on
  57      * which the error appears, which will be be a value >= 1.  If the
  58      * parse does not support line numbers, the value will be <= 0.
  59      * @stable ICU 2.0
  60      */
  61     int32_t        line;
  62
  63     /**
  64      * The character offset to the error.  If the line field is >= 1,
  65      * then this is the offset from the start of the line.  Otherwise,
  66      * this is the offset from the start of the text.  If the parser
  67      * does not support this field, it will have a value < 0.
  68      * @stable ICU 2.0
  69      */
  70     int32_t        offset;
  71
  72     /**
  73      * Textual context before the error.  Null-terminated.  The empty
  74      * string if not supported by parser.
  75      * @stable ICU 2.0
  76      */
  77     UChar          preContext[U_PARSE_CONTEXT_LEN];
  78
  79     /**
  80      * The error itself and/or textual context after the error.
  81      * Null-terminated.  The empty string if not supported by parser.
  82      * @stable ICU 2.0
  83      */
  84     UChar          postContext[U_PARSE_CONTEXT_LEN];
  85
  86 } UParseError;
  87
  88 #endif