casacore
JsonParser.h
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1//# JsonParser.h: Class for parsing Json-style key:value lines
2//# Copyright (C) 2016
3//# Associated Universities, Inc. Washington DC, USA.
4//#
5//# This library is free software; you can redistribute it and/or modify it
6//# under the terms of the GNU Library General Public License as published by
7//# the Free Software Foundation; either version 2 of the License, or (at your
8//# option) any later version.
9//#
10//# This library is distributed in the hope that it will be useful, but WITHOUT
11//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13//# License for more details.
14//#
15//# You should have received a copy of the GNU Library General Public License
16//# along with this library; if not, write to the Free Software Foundation,
17//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18//#
19//# Correspondence concerning AIPS++ should be addressed as follows:
20//# Internet email: aips2-request@nrao.edu.
21//# Postal address: AIPS++ Project Office
22//# National Radio Astronomy Observatory
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25//#
26//# $Id$
27
28#ifndef CASA_JSONPARSER_H
29#define CASA_JSONPARSER_H
30
31//# Includes
32#include <casacore/casa/BasicSL/String.h>
33#include <casacore/casa/Exceptions/Error.h>
34
35extern "C" {
36 int JsonGramwrap(); // yywrap
37}
38
39namespace casacore {
40
41 //# Forward Declarations
42 class JsonValue;
43 class JSonKVMap;
44
45 // <summary>
46 // Class for parsing Json-style key:value lines.
47 // </summary>
48
49 // <use visibility=export>
50 // <reviewed reviewer="" date="" tests="tJsonKVMap">
51 // </reviewed>
52
53 //# <prerequisite>
54 //# </prerequisite>
55
56 // <synopsis>
57 // JsonParser is a class for parsing JSON files. Its function 'parse'
58 // is the main function to do so.
59 // It can handle any JSON file (not only those generated by JsonOut).
60 // It supports (i.e., strips) possible comments in C, C++ and Python style.
61 // It also supports complex numbers (structs with fields "r" and "i").
62 // Escaped characters in a string value are translated into their ASCII counterparts.
63 //
64 // The result of the parser is a JsonKVMap object containing all fields
65 // and values (scalars, arrays and structs, possibly nested in any way).
66 // The values in the map are stored as JsonValue objects, which have functions to
67 // get the value with the proper type.
68 // </synopsis>
69
70 // <example>
71 // The following example is the opposite of the one given for class JsonOut.
72 // <srcblock>
73 // // Parse the given JSON file.
74 // JsonKVMap jmap = JsonParser::parseFile (fileName);
75 // // Check if the version is correct.
76 // AlwaysAssert (jmap.getInt("Version", 1) == 1, AipsError);
77 // uInt axis = jmap.get("Axis").getInt();
78 // // Get the vector of names from the map and JsonValue.
79 // Vector<String> names(jmap.get("Images").getArrayString());
80 // </srcblock>
81 // </example>
82
83 // <motivation>
84 // JSON is a commonly used interchange format.
85 // However, commonly available parsers do not support data type Complex. Also, comments
86 // are often not supported (alas standard Json does not allow comments).
87 // </motivation>
88
89 //# <todo asof="1996/03/10">
90 //# <li>
91 //# </todo>
92
94 {
95 public:
96 // Parse the command in the given string and return the resulting map.
97 static JsonKVMap parse (const String& command);
98
99 // Parse the given file and return the resulting map.
100 // Comments are ignored; they can be indicated by // or # till eol
101 // or be enclosed in / * and * /.
102 static JsonKVMap parseFile (const String& fileName);
103
104 // Give the next chunk of input for the scanner.
105 static int input (char* buf, int max_size);
106
107 // Give the current position (for read or update).
108 static int& position()
109 { return theirPosition; }
110
111 // Remove all possible escape characters and convert as needed (including <src>\uxxxx</src>).
112 static String removeEscapes (const String& in);
113
114 // Let the parser set the final KeyValueMap.
115 static void setMap (JsonKVMap* map)
116 { theirJsonMap = map; }
117
118 private:
119 static int theirPosition;
120 static const char* theirCommand;
122 };
123
124 // The global yyerror function for the parser.
125 // It throws an exception with the current token.
126 void JsonGramerror (const char*);
127
128 // </group>
129
130} // end namespace
131
132#endif
int JsonGramwrap()
static JsonKVMap * theirJsonMap
Definition: JsonParser.h:121
static int theirPosition
Definition: JsonParser.h:119
static JsonKVMap parse(const String &command)
Parse the command in the given string and return the resulting map.
static int input(char *buf, int max_size)
Give the next chunk of input for the scanner.
static const char * theirCommand
Definition: JsonParser.h:120
static void setMap(JsonKVMap *map)
Let the parser set the final KeyValueMap.
Definition: JsonParser.h:115
static String removeEscapes(const String &in)
Remove all possible escape characters and convert as needed (including \uxxxx).
static int & position()
Give the current position (for read or update).
Definition: JsonParser.h:108
static JsonKVMap parseFile(const String &fileName)
Parse the given file and return the resulting map.
String: the storage and methods of handling collections of characters.
Definition: String.h:225
this file contains all the compiler specific defines
Definition: mainpage.dox:28
void JsonGramerror(const char *)
The global yyerror function for the parser.