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Unverified Commit b53c6e2f by Niels Lohmann
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✨ ignore comments

parent e7452d87
Showing with 190 additions and 6 deletions
include/nlohmann/detail/input/lexer.hpp
......@@ -112,8 +112,11 @@ class lexer : public lexer_base<BasicJsonType>
public:
using token_type = typename lexer_base<BasicJsonType>::token_type;
explicit lexer(InputAdapterType&& adapter)
: ia(std::move(adapter)), decimal_point_char(static_cast<char_int_type>(get_decimal_point())) {}
explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false)
: ia(std::move(adapter))
, ignore_comments(ignore_comments_)
, decimal_point_char(static_cast<char_int_type>(get_decimal_point()))
{}
// delete because of pointer members
lexer(const lexer&) = delete;
......@@ -131,7 +134,7 @@ class lexer : public lexer_base<BasicJsonType>
JSON_HEDLEY_PURE
static char get_decimal_point() noexcept
{
const auto loc = localeconv();
const auto* loc = localeconv();
assert(loc != nullptr);
return (loc->decimal_point == nullptr) ? '.' : *(loc->decimal_point);
}
......@@ -826,6 +829,71 @@ class lexer : public lexer_base<BasicJsonType>
}
}
/*!
* @brief scan a comment
* @return whether comment could be scanned successfully
*/
bool scan_comment()
{
// remember character after '/' to distinguish comment types
const auto comment_char = get();
// expect // or /* to start a comment
if (comment_char != '/' and comment_char != '*')
{
return false;
}
while (true)
{
switch (get())
{
// EOF inside a /* comment is an error, in // it is OK
case std::char_traits<char_type>::eof():
case '\0':
{
return comment_char == '/';
}
// a newline ends the // comment
case '\n':
case '\r':
{
if (comment_char == '/')
{
return true;
}
break;
}
// */ ends the /* comment
case '*':
{
if (comment_char == '*')
{
switch (get())
{
case '/':
{
return true;
}
default:
{
unget();
break;
}
}
}
break;
}
default:
break;
}
}
}
JSON_HEDLEY_NON_NULL(2)
static void strtof(float& f, const char* str, char** endptr) noexcept
{
......@@ -1431,6 +1499,17 @@ scan_number_done:
}
while (current == ' ' or current == '\t' or current == '\n' or current == '\r');
// ignore comments
if (ignore_comments and current == '/')
{
if (not scan_comment())
{
error_message = "invalid comment";
return token_type::parse_error;
}
get();
}
switch (current)
{
// structural characters
......@@ -1499,6 +1578,9 @@ scan_number_done:
/// input adapter
InputAdapterType ia;
/// whether comments should be ignored (true) or signaled as errors (false)
const bool ignore_comments = false;
/// the current character
char_int_type current = std::char_traits<char_type>::eof();
......
single_include/nlohmann/json.hpp
......@@ -8179,8 +8179,11 @@ class lexer : public lexer_base<BasicJsonType>
public:
using token_type = typename lexer_base<BasicJsonType>::token_type;
explicit lexer(InputAdapterType&& adapter)
: ia(std::move(adapter)), decimal_point_char(static_cast<char_int_type>(get_decimal_point())) {}
explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false)
: ia(std::move(adapter))
, ignore_comments(ignore_comments_)
, decimal_point_char(static_cast<char_int_type>(get_decimal_point()))
{}
// delete because of pointer members
lexer(const lexer&) = delete;
......@@ -8198,7 +8201,7 @@ class lexer : public lexer_base<BasicJsonType>
JSON_HEDLEY_PURE
static char get_decimal_point() noexcept
{
const auto loc = localeconv();
const auto* loc = localeconv();
assert(loc != nullptr);
return (loc->decimal_point == nullptr) ? '.' : *(loc->decimal_point);
}
......@@ -8893,6 +8896,71 @@ class lexer : public lexer_base<BasicJsonType>
}
}
/*!
* @brief scan a comment
* @return whether comment could be scanned successfully
*/
bool scan_comment()
{
// remember character after '/' to distinguish comment types
const auto comment_char = get();
// expect // or /* to start a comment
if (comment_char != '/' and comment_char != '*')
{
return false;
}
while (true)
{
switch (get())
{
// EOF inside a /* comment is an error, in // it is OK
case std::char_traits<char_type>::eof():
case '\0':
{
return comment_char == '/';
}
// a newline ends the // comment
case '\n':
case '\r':
{
if (comment_char == '/')
{
return true;
}
break;
}
// */ ends the /* comment
case '*':
{
if (comment_char == '*')
{
switch (get())
{
case '/':
{
return true;
}
default:
{
unget();
break;
}
}
}
break;
}
default:
break;
}
}
}
JSON_HEDLEY_NON_NULL(2)
static void strtof(float& f, const char* str, char** endptr) noexcept
{
......@@ -9498,6 +9566,17 @@ scan_number_done:
}
while (current == ' ' or current == '\t' or current == '\n' or current == '\r');
// ignore comments
if (ignore_comments and current == '/')
{
if (not scan_comment())
{
error_message = "invalid comment";
return token_type::parse_error;
}
get();
}
switch (current)
{
// structural characters
......@@ -9566,6 +9645,9 @@ scan_number_done:
/// input adapter
InputAdapterType ia;
/// whether comments should be ignored (true) or signaled as errors (false)
const bool ignore_comments = false;
/// the current character
char_int_type current = std::char_traits<char_type>::eof();
......
test/src/unit-class_lexer.cpp
......@@ -127,6 +127,8 @@ TEST_CASE("lexer class")
// store scan() result
const auto res = scan_string(s.c_str());
CAPTURE(s);
switch (c)
{
// single characters that are valid tokens
......@@ -161,6 +163,9 @@ TEST_CASE("lexer class")
break;
}
// case ('/'):
// break;
// anything else is not expected
default:
{
......@@ -179,4 +184,19 @@ TEST_CASE("lexer class")
s += "\"";
CHECK((scan_string(s.c_str()) == json::lexer::token_type::value_string));
}
// SECTION("ignore comments")
// {
// CHECK((scan_string("/") == json::lexer::token_type::parse_error));
//
// CHECK((scan_string("/!") == json::lexer::token_type::parse_error));
// CHECK((scan_string("/*") == json::lexer::token_type::parse_error));
// CHECK((scan_string("/**") == json::lexer::token_type::parse_error));
//
// CHECK((scan_string("//") == json::lexer::token_type::end_of_input));
// CHECK((scan_string("/**/") == json::lexer::token_type::end_of_input));
// CHECK((scan_string("/** /") == json::lexer::token_type::parse_error));
//
// CHECK((scan_string("/***/") == json::lexer::token_type::end_of_input));
// }
}
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