1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 **********************************************************************
5 *   Copyright (C) 1999-2005, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 **********************************************************************
8 *   Date        Name        Description
9 *   03/14/00    aliu        Creation.
10 *   06/27/00    aliu        Change from C++ class to C struct
11 **********************************************************************
12 */
13 #ifndef PARSEERR_H
14 #define PARSEERR_H
15 
16 #include "unicode/utypes.h"
17 
18 
19 /**
20  * \file
21  * \brief C API: Parse Error Information
22  */
23 /**
24  * The capacity of the context strings in UParseError.
25  * @stable ICU 2.0
26  */
27 enum { U_PARSE_CONTEXT_LEN = 16 };
28 
29 /**
30  * A UParseError struct is used to returned detailed information about
31  * parsing errors.  It is used by ICU parsing engines that parse long
32  * rules, patterns, or programs, where the text being parsed is long
33  * enough that more information than a UErrorCode is needed to
34  * localize the error.
35  *
36  * <p>The line, offset, and context fields are optional; parsing
37  * engines may choose not to use to use them.
38  *
39  * <p>The preContext and postContext strings include some part of the
40  * context surrounding the error.  If the source text is "let for=7"
41  * and "for" is the error (e.g., because it is a reserved word), then
42  * some examples of what a parser might produce are the following:
43  *
44  * <pre>
45  * preContext   postContext
46  * ""           ""            The parser does not support context
47  * "let "       "=7"          Pre- and post-context only
48  * "let "       "for=7"       Pre- and post-context and error text
49  * ""           "for"         Error text only
50  * </pre>
51  *
52  * <p>Examples of engines which use UParseError (or may use it in the
53  * future) are Transliterator, RuleBasedBreakIterator, and
54  * RegexPattern.
55  *
56  * @stable ICU 2.0
57  */
58 typedef struct UParseError {
59 
60     /**
61      * The line on which the error occured.  If the parser uses this
62      * field, it sets it to the line number of the source text line on
63      * which the error appears, which will be be a value >= 1.  If the
64      * parse does not support line numbers, the value will be <= 0.
65      * @stable ICU 2.0
66      */
67     int32_t        line;
68 
69     /**
70      * The character offset to the error.  If the line field is >= 1,
71      * then this is the offset from the start of the line.  Otherwise,
72      * this is the offset from the start of the text.  If the parser
73      * does not support this field, it will have a value < 0.
74      * @stable ICU 2.0
75      */
76     int32_t        offset;
77 
78     /**
79      * Textual context before the error.  Null-terminated.  The empty
80      * string if not supported by parser.
81      * @stable ICU 2.0
82      */
83     UChar          preContext[U_PARSE_CONTEXT_LEN];
84 
85     /**
86      * The error itself and/or textual context after the error.
87      * Null-terminated.  The empty string if not supported by parser.
88      * @stable ICU 2.0
89      */
90     UChar          postContext[U_PARSE_CONTEXT_LEN];
91 
92 } UParseError;
93 
94 #endif
95