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working on user-defined exceptions (#244), added location to parse er…
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…rors (#301)
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@nlohmann
nlohmann committed Nov 14, 2016
1 parent 9d5d5e6 commit 3c427e4
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Showing 9 changed files with 568 additions and 356 deletions.
151 changes: 116 additions & 35 deletions src/json.hpp
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Expand Up @@ -50,7 +50,7 @@ SOFTWARE.
#include <memory> // addressof, allocator, allocator_traits, unique_ptr
#include <numeric> // accumulate
#include <sstream> // stringstream
#include <stdexcept> // domain_error, invalid_argument, out_of_range
#include <stdexcept> // domain_error, out_of_range
#include <string> // getline, stoi, string, to_string
#include <type_traits> // add_pointer, enable_if, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_floating_point, is_integral, is_nothrow_move_assignable, std::is_nothrow_move_constructible, std::is_pointer, std::is_reference, std::is_same, remove_const, remove_pointer, remove_reference
#include <utility> // declval, forward, make_pair, move, pair, swap
Expand Down Expand Up @@ -245,6 +245,78 @@ template <
>
class basic_json
{
public:
/*!
@brief general exception of the @ref basic_json class
id | name | description
--- | ------------------------------ | ---------------------------------
101 | json.exception.parse_error.101 | An unexpected token was read while deserializing a JSON text.
102 | json.exception.parse_error.102 | An incomplete Unicode surrogate pair was read.
103 | json.exception.parse_error.103 | A Unicode code point above 0x10FFFF was read.
104 | json.exception.parse_error.104 | A JSON Patch must be an array of objects.
105 | json.exception.parse_error.105 | A JSON Patch operation contained an error.
201 | json.exception.invalid_iterator.201 | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid.
*/
class exception : public std::exception
{
public:
/// create exception with id an explanatory string
exception(int id_, const std::string& ename, const std::string& what_arg_)
: id(id_),
what_arg("[json.exception." + ename + "." + std::to_string(id_) + "] " + what_arg_)
{}

/// returns the explanatory string
virtual const char* what() const noexcept
{
return what_arg.c_str();
}

/// the id of the exception
const int id;

private:
/// the explanatory string
const std::string what_arg;
};

/*!
@brief exception indicating a parse error
This excpetion is thrown by the library when a parse error occurs. Parse
errors can occur during the deserialization of JSON text as well as when
using JSON Patch.
*/
class parse_error : public exception
{
public:
/*!
@brief create a parse error exception
@param[in] id_ the id of the exception
@param[in] byte_ the byte index where the error occured (or 0 if
the position cannot be determined)
@param[in] what_arg_ the explanatory string
*/
parse_error(int id_, int byte_, const std::string what_arg_)
: exception(id_, "parse_error", "parse error" +
(byte_ != 0 ? (" at " + std::to_string(byte_)) : "") +
": " + what_arg_),
byte(byte_)
{}

/// byte index of the parse error
const int byte;
};

class invalid_iterator : public exception
{
public:
invalid_iterator(int id_, const std::string what_arg_)
: exception(id_, "invalid_iterator", what_arg_)
{}
};

private:
/// workaround type for MSVC
using basic_json_t = basic_json<ObjectType, ArrayType, StringType,
Expand Down Expand Up @@ -1820,7 +1892,7 @@ class basic_json
@pre Iterators @a first and @a last must be initialized. **This
precondition is enforced with an assertion.**
@throw std::domain_error if iterators are not compatible; that is, do not
@throw invalid_iterator if iterators are not compatible; that is, do not
belong to the same JSON value; example: `"iterators are not compatible"`
@throw std::out_of_range if iterators are for a primitive type (number,
boolean, or string) where an out of range error can be detected easily;
Expand All @@ -1847,7 +1919,7 @@ class basic_json
// make sure iterator fits the current value
if (first.m_object != last.m_object)
{
JSON_THROW(std::domain_error("iterators are not compatible"));
JSON_THROW(invalid_iterator(201, "iterators are not compatible"));
}

// copy type from first iterator
Expand Down Expand Up @@ -6126,7 +6198,7 @@ class basic_json
@param[in,out] i input stream to read a serialized JSON value from
@param[in,out] j JSON value to write the deserialized input to
@throw std::invalid_argument in case of parse errors
@throw parse_error in case of parse errors
@complexity Linear in the length of the input. The parser is a predictive
LL(1) parser.
Expand Down Expand Up @@ -7668,15 +7740,15 @@ class basic_json
@throw std::out_of_range if code point is > 0x10ffff; example: `"code
points above 0x10FFFF are invalid"`
@throw std::invalid_argument if the low surrogate is invalid; example:
@throw parse_error if the low surrogate is invalid; example:
`""missing or wrong low surrogate""`
@complexity Constant.
@see <http://en.wikipedia.org/wiki/UTF-8#Sample_code>
*/
static string_t to_unicode(const std::size_t codepoint1,
const std::size_t codepoint2 = 0)
string_t to_unicode(const std::size_t codepoint1,
const std::size_t codepoint2 = 0) const
{
// calculate the code point from the given code points
std::size_t codepoint = codepoint1;
Expand All @@ -7699,7 +7771,7 @@ class basic_json
}
else
{
JSON_THROW(std::invalid_argument("missing or wrong low surrogate"));
JSON_THROW(parse_error(102, get_position(), "missing or wrong low surrogate"));
}
}

Expand Down Expand Up @@ -7733,7 +7805,7 @@ class basic_json
}
else
{
JSON_THROW(std::out_of_range("code points above 0x10FFFF are invalid"));
JSON_THROW(parse_error(103, get_position(), "code points above 0x10FFFF are invalid"));
}

return result;
Expand Down Expand Up @@ -7991,6 +8063,7 @@ class basic_json
goto basic_json_parser_6;
}
{
position += static_cast<size_t>((m_cursor - m_start));
continue;
}
basic_json_parser_9:
Expand Down Expand Up @@ -8724,6 +8797,7 @@ class basic_json

}

position += static_cast<size_t>((m_cursor - m_start));
return last_token_type;
}

Expand Down Expand Up @@ -8941,7 +9015,7 @@ class basic_json
// make sure there is a subsequent unicode
if ((i + 6 >= m_limit) or * (i + 5) != '\\' or * (i + 6) != 'u')
{
JSON_THROW(std::invalid_argument("missing low surrogate"));
JSON_THROW(parse_error(102, get_position(), "missing low surrogate"));
}

// get code yyyy from uxxxx\uyyyy
Expand All @@ -8954,7 +9028,7 @@ class basic_json
else if (codepoint >= 0xDC00 and codepoint <= 0xDFFF)
{
// we found a lone low surrogate
JSON_THROW(std::invalid_argument("missing high surrogate"));
JSON_THROW(parse_error(102, get_position(), "missing high surrogate"));
}
else
{
Expand Down Expand Up @@ -9151,6 +9225,11 @@ class basic_json
result.m_type = type;
}

constexpr size_t get_position() const
{
return position;
}

private:
/// optional input stream
std::istream* m_stream = nullptr;
Expand All @@ -9168,6 +9247,8 @@ class basic_json
const lexer_char_t* m_limit = nullptr;
/// the last token type
token_type last_token_type = token_type::end_of_input;
/// current position in the input (read bytes)
size_t position = 0;
};

/*!
Expand Down Expand Up @@ -9422,24 +9503,24 @@ class basic_json
{
if (t != last_token)
{
std::string error_msg = "parse error - unexpected ";
std::string error_msg = "unexpected ";
error_msg += (last_token == lexer::token_type::parse_error ? ("'" + m_lexer.get_token_string() +
"'") :
lexer::token_type_name(last_token));
error_msg += "; expected " + lexer::token_type_name(t);
JSON_THROW(std::invalid_argument(error_msg));
JSON_THROW(parse_error(101, m_lexer.get_position(), error_msg));
}
}

void unexpect(typename lexer::token_type t) const
{
if (t == last_token)
{
std::string error_msg = "parse error - unexpected ";
std::string error_msg = "unexpected ";
error_msg += (last_token == lexer::token_type::parse_error ? ("'" + m_lexer.get_token_string() +
"'") :
lexer::token_type_name(last_token));
JSON_THROW(std::invalid_argument(error_msg));
JSON_THROW(parse_error(101, m_lexer.get_position(), error_msg));
}
}

Expand Down Expand Up @@ -9637,9 +9718,9 @@ class basic_json
@complexity Linear in the length of the JSON pointer.
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw std::invalid_argument if an array index was not a number
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw parse_error if an array index was not a number
*/
reference get_unchecked(pointer ptr) const
{
Expand Down Expand Up @@ -10086,9 +10167,9 @@ class basic_json
@complexity Constant.
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw std::invalid_argument if an array index was not a number
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw parse_error if an array index was not a number
@liveexample{The behavior is shown in the example.,operatorjson_pointer}
Expand All @@ -10113,9 +10194,9 @@ class basic_json
@complexity Constant.
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw std::invalid_argument if an array index was not a number
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw parse_error if an array index was not a number
@liveexample{The behavior is shown in the example.,operatorjson_pointer_const}
Expand All @@ -10138,9 +10219,9 @@ class basic_json
@complexity Constant.
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw std::invalid_argument if an array index was not a number
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw parse_error if an array index was not a number
@liveexample{The behavior is shown in the example.,at_json_pointer}
Expand All @@ -10163,9 +10244,9 @@ class basic_json
@complexity Constant.
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw std::invalid_argument if an array index was not a number
@throw std::out_of_range if the JSON pointer can not be resolved
@throw std::domain_error if an array index begins with '0'
@throw parse_error if an array index was not a number
@liveexample{The behavior is shown in the example.,at_json_pointer_const}
Expand Down Expand Up @@ -10416,7 +10497,7 @@ class basic_json
if (not json_patch.is_array())
{
// a JSON patch must be an array of objects
JSON_THROW(std::invalid_argument("JSON patch must be an array of objects"));
JSON_THROW(parse_error(104, 0, "JSON patch must be an array of objects"));
}

// iterate and apply th eoperations
Expand All @@ -10436,13 +10517,13 @@ class basic_json
// check if desired value is present
if (it == val.m_value.object->end())
{
JSON_THROW(std::invalid_argument(error_msg + " must have member '" + member + "'"));
JSON_THROW(parse_error(105, 0, error_msg + " must have member '" + member + "'"));
}

// check if result is of type string
if (string_type and not it->second.is_string())
{
JSON_THROW(std::invalid_argument(error_msg + " must have string member '" + member + "'"));
JSON_THROW(parse_error(105, 0, error_msg + " must have string member '" + member + "'"));
}

// no error: return value
Expand All @@ -10452,7 +10533,7 @@ class basic_json
// type check
if (not val.is_object())
{
JSON_THROW(std::invalid_argument("JSON patch must be an array of objects"));
JSON_THROW(parse_error(104, 0, "JSON patch must be an array of objects"));
}

// collect mandatory members
Expand Down Expand Up @@ -10535,7 +10616,7 @@ class basic_json
{
// op must be "add", "remove", "replace", "move", "copy", or
// "test"
JSON_THROW(std::invalid_argument("operation value '" + op + "' is invalid"));
JSON_THROW(parse_error(105, 0, "operation value '" + op + "' is invalid"));
}
}
}
Expand Down

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