From 94af8abdff77de3526aca2c2ccfd03517ee678e5 Mon Sep 17 00:00:00 2001
From: Niels <niels.lohmann@gmail.com>
Date: Wed, 13 Apr 2016 23:23:54 +0200
Subject: [PATCH] overworked reference token parsing
---
src/json.hpp | 84 ++++++++++++++++++++++++++++++++++++-----------
src/json.hpp.re2c | 84 ++++++++++++++++++++++++++++++++++++-----------
test/unit.cpp | 23 +++++++++++++
3 files changed, 151 insertions(+), 40 deletions(-)
diff --git a/src/json.hpp b/src/json.hpp
index f2c3813a..84e10064 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -8911,10 +8911,21 @@ basic_json_parser_64:
/// the reference tokens
std::vector<std::string> reference_tokens {};
- /// replace all occurrences of a substring by another string
- void replace_substring(std::string& s,
- const std::string& f,
- const std::string& t)
+ /*!
+ @brief replace all occurrences of a substring by another string
+
+ @param[in,out] s the string to manipulate
+ @param[in] f the substring to replace with @a t
+ @param[out] t the string to replace @a f
+
+ @return The string @a s where all occurrences of @a f are replaced
+ with @a t.
+
+ @pre The search string @f must not be empty.
+ */
+ static void replace_substring(std::string& s,
+ const std::string& f,
+ const std::string& t)
{
assert(not f.empty());
@@ -8941,26 +8952,49 @@ basic_json_parser_64:
throw std::domain_error("JSON pointer must be empty or begin with '/'");
}
- // tokenize reference string
- auto ptr = std::strtok(&reference_string[0], "/");
- while (ptr != nullptr)
+ // extract the reference tokens:
+ // - slash: position of the last read slash (or end of string)
+ // - start: position after the previous slash
+ for (
+ // search for the first slash after the first character
+ size_t slash = reference_string.find_first_of("/", 1),
+ // set the beginning of the first reference token
+ start = 1;
+ // we can stop if start == string::npos+1 = 0
+ start != 0;
+ // set the beginning of the next reference token
+ // (could be 0 if slash == std::string::npos)
+ start = slash + 1,
+ // find next slash
+ slash = reference_string.find_first_of("/", start))
{
- reference_tokens.push_back(ptr);
- ptr = std::strtok(NULL, "/");
- }
+ // use the text between the beginning of the reference token
+ // (start) and the last slash (slash).
+ auto reference_token = reference_string.substr(start, slash - start);
- // special case: reference string was just "/"
- if (reference_tokens.empty())
- {
- reference_tokens.push_back("");
- }
+ // check reference tokens are properly escaped
+ for (size_t pos = reference_token.find_first_of("~");
+ pos != std::string::npos;
+ pos = reference_token.find_first_of("~", pos + 1))
+ {
+ assert(reference_token[pos] == '~');
+
+ // ~ must be followed by 0 or 1
+ if (pos == reference_token.size() - 1 or
+ (reference_token[pos + 1] != '0' and
+ reference_token[pos + 1] != '1'))
+ {
+ throw std::domain_error("escape error: '~' must be followed with '0' or '1'");
+ }
+ }
- for (auto& reference_token : reference_tokens)
- {
// first transform any occurrence of the sequence '~1' to '/'
replace_substring(reference_token, "~1", "/");
// then transform any occurrence of the sequence '~0' to '~'
replace_substring(reference_token, "~0", "~");
+
+ // store the reference token
+ reference_tokens.push_back(reference_token);
}
}
};
@@ -9026,9 +9060,9 @@ struct hash<nlohmann::json>
/*!
@brief user-defined string literal for JSON values
-This operator implements a user-defined string literal for JSON objects. It can
-be used by adding \p "_json" to a string literal and returns a JSON object if
-no parse error occurred.
+This operator implements a user-defined string literal for JSON objects. It
+can be used by adding \p "_json" to a string literal and returns a JSON object
+if no parse error occurred.
@param[in] s a string representation of a JSON object
@return a JSON object
@@ -9040,6 +9074,16 @@ inline nlohmann::json operator "" _json(const char* s, std::size_t)
return nlohmann::json::parse(reinterpret_cast<const nlohmann::json::string_t::value_type*>(s));
}
+/*!
+@brief user-defined string literal for JSON pointer
+
+@since version 2.0.0
+*/
+inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std::size_t)
+{
+ return nlohmann::json::json_pointer(s);
+}
+
// restore GCC/clang diagnostic settings
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
#pragma GCC diagnostic pop
diff --git a/src/json.hpp.re2c b/src/json.hpp.re2c
index ea62dca5..5501b35c 100644
--- a/src/json.hpp.re2c
+++ b/src/json.hpp.re2c
@@ -8190,10 +8190,21 @@ class basic_json
/// the reference tokens
std::vector<std::string> reference_tokens {};
- /// replace all occurrences of a substring by another string
- void replace_substring(std::string& s,
- const std::string& f,
- const std::string& t)
+ /*!
+ @brief replace all occurrences of a substring by another string
+
+ @param[in,out] s the string to manipulate
+ @param[in] f the substring to replace with @a t
+ @param[out] t the string to replace @a f
+
+ @return The string @a s where all occurrences of @a f are replaced
+ with @a t.
+
+ @pre The search string @f must not be empty.
+ */
+ static void replace_substring(std::string& s,
+ const std::string& f,
+ const std::string& t)
{
assert(not f.empty());
@@ -8220,26 +8231,49 @@ class basic_json
throw std::domain_error("JSON pointer must be empty or begin with '/'");
}
- // tokenize reference string
- auto ptr = std::strtok(&reference_string[0], "/");
- while (ptr != nullptr)
+ // extract the reference tokens:
+ // - slash: position of the last read slash (or end of string)
+ // - start: position after the previous slash
+ for (
+ // search for the first slash after the first character
+ size_t slash = reference_string.find_first_of("/", 1),
+ // set the beginning of the first reference token
+ start = 1;
+ // we can stop if start == string::npos+1 = 0
+ start != 0;
+ // set the beginning of the next reference token
+ // (could be 0 if slash == std::string::npos)
+ start = slash + 1,
+ // find next slash
+ slash = reference_string.find_first_of("/", start))
{
- reference_tokens.push_back(ptr);
- ptr = std::strtok(NULL, "/");
- }
+ // use the text between the beginning of the reference token
+ // (start) and the last slash (slash).
+ auto reference_token = reference_string.substr(start, slash - start);
- // special case: reference string was just "/"
- if (reference_tokens.empty())
- {
- reference_tokens.push_back("");
- }
+ // check reference tokens are properly escaped
+ for (size_t pos = reference_token.find_first_of("~");
+ pos != std::string::npos;
+ pos = reference_token.find_first_of("~", pos + 1))
+ {
+ assert(reference_token[pos] == '~');
+
+ // ~ must be followed by 0 or 1
+ if (pos == reference_token.size() - 1 or
+ (reference_token[pos + 1] != '0' and
+ reference_token[pos + 1] != '1'))
+ {
+ throw std::domain_error("escape error: '~' must be followed with '0' or '1'");
+ }
+ }
- for (auto& reference_token : reference_tokens)
- {
// first transform any occurrence of the sequence '~1' to '/'
replace_substring(reference_token, "~1", "/");
// then transform any occurrence of the sequence '~0' to '~'
replace_substring(reference_token, "~0", "~");
+
+ // store the reference token
+ reference_tokens.push_back(reference_token);
}
}
};
@@ -8305,9 +8339,9 @@ struct hash<nlohmann::json>
/*!
@brief user-defined string literal for JSON values
-This operator implements a user-defined string literal for JSON objects. It can
-be used by adding \p "_json" to a string literal and returns a JSON object if
-no parse error occurred.
+This operator implements a user-defined string literal for JSON objects. It
+can be used by adding \p "_json" to a string literal and returns a JSON object
+if no parse error occurred.
@param[in] s a string representation of a JSON object
@return a JSON object
@@ -8319,6 +8353,16 @@ inline nlohmann::json operator "" _json(const char* s, std::size_t)
return nlohmann::json::parse(reinterpret_cast<const nlohmann::json::string_t::value_type*>(s));
}
+/*!
+@brief user-defined string literal for JSON pointer
+
+@since version 2.0.0
+*/
+inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std::size_t)
+{
+ return nlohmann::json::json_pointer(s);
+}
+
// restore GCC/clang diagnostic settings
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
#pragma GCC diagnostic pop
diff --git a/test/unit.cpp b/test/unit.cpp
index d6ec00a7..7c8fd8b7 100644
--- a/test/unit.cpp
+++ b/test/unit.cpp
@@ -12118,6 +12118,29 @@ TEST_CASE("JSON pointers")
CHECK(j_const[""] == json::json_pointer("/").get(j_const));
CHECK(j_const[" "] == json::json_pointer("/ ").get(j_const));
}
+
+ SECTION("user-defined string literal")
+ {
+ // the whole document
+ CHECK(""_json_pointer.get(j) == j);
+
+ // array access
+ CHECK("/foo"_json_pointer.get(j) == j["foo"]);
+ CHECK("/foo/0"_json_pointer.get(j) == j["foo"][0]);
+ CHECK("/foo/1"_json_pointer.get(j) == j["foo"][1]);
+ }
+
+ SECTION("errors")
+ {
+ CHECK_THROWS_AS(json::json_pointer("foo"), std::domain_error);
+ CHECK_THROWS_WITH(json::json_pointer("foo"), "JSON pointer must be empty or begin with '/'");
+
+ CHECK_THROWS_AS(json::json_pointer("/~~"), std::domain_error);
+ CHECK_THROWS_WITH(json::json_pointer("/~~"), "escape error: '~' must be followed with '0' or '1'");
+
+ CHECK_THROWS_AS(json::json_pointer("/~"), std::domain_error);
+ CHECK_THROWS_WITH(json::json_pointer("/~"), "escape error: '~' must be followed with '0' or '1'");
+ }
}
}