diff --git a/.gitignore b/.gitignore
index 206731f0..432d6ac3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,3 +46,5 @@ CMakeFiles
libjson.a
Testing
+
+.idea
\ No newline at end of file
diff --git a/.idea/codeStyleSettings.xml b/.idea/codeStyleSettings.xml
deleted file mode 100644
index 65c39702..00000000
--- a/.idea/codeStyleSettings.xml
+++ /dev/null
@@ -1,35 +0,0 @@
-
-
-
-
-
-
-
\ No newline at end of file
diff --git a/.idea/json.iml b/.idea/json.iml
deleted file mode 100644
index bc2cd874..00000000
--- a/.idea/json.iml
+++ /dev/null
@@ -1,8 +0,0 @@
-
-
-
-
-
-
-
-
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
deleted file mode 100644
index 6b328020..00000000
--- a/.idea/misc.xml
+++ /dev/null
@@ -1,5 +0,0 @@
-
-
-
-
-
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
deleted file mode 100644
index cd370d1e..00000000
--- a/.idea/modules.xml
+++ /dev/null
@@ -1,8 +0,0 @@
-
-
-
-
-
-
-
-
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
deleted file mode 100644
index 94a25f7f..00000000
--- a/.idea/vcs.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-
-
-
-
-
-
\ No newline at end of file
diff --git a/header_only/json.h b/header_only/json.h
index c8f5047c..13a2b626 100644
--- a/header_only/json.h
+++ b/header_only/json.h
@@ -418,9 +418,15 @@ class json
/// read the next character, stripping whitespace
bool next();
/// raise an exception with an error message
- inline void error(const std::string&) __attribute__((noreturn));
+ inline void error(const std::string&) const __attribute__((noreturn));
/// parse a quoted string
inline std::string parseString();
+ /// transforms a unicode codepoint to it's UTF-8 presentation
+ std::string codePointToUTF8(unsigned int codePoint) const;
+ /// parses 4 hex characters that represent a unicode code point
+ inline unsigned int parse4HexCodePoint();
+ /// parses \uXXXX[\uXXXX] unicode escape characters
+ inline std::string parseUnicodeEscape();
/// parse a Boolean "true"
inline void parseTrue();
/// parse a Boolean "false"
@@ -2434,9 +2440,9 @@ json json::parser::parse()
// remember position of number's first character
const auto _firstpos_ = pos_ - 1;
- while (next() and (std::isdigit(current_) || current_ == '.'
- || current_ == 'e' || current_ == 'E'
- || current_ == '+' || current_ == '-'));
+ while (next() and (std::isdigit(current_) or current_ == '.'
+ or current_ == 'e' or current_ == 'E'
+ or current_ == '+' or current_ == '-'));
try
{
@@ -2512,7 +2518,7 @@ the error message \p msg), and the last read token.
@exception std::invalid_argument whenever the function is called
*/
-void json::parser::error(const std::string& msg)
+void json::parser::error(const std::string& msg) const
{
throw std::invalid_argument("parse error at position " +
std::to_string(pos_) + ": " + msg +
@@ -2542,14 +2548,19 @@ std::string json::parser::parseString()
// the result of the parse process
std::string result;
- // iterate with pos_ over the whole string
+ // iterate with pos_ over the whole input until we found the end and return
+ // or we exit via error()
for (; pos_ < buffer_.size(); pos_++)
{
char currentChar = buffer_[pos_];
- // uneven amount of backslashes means the user wants to escape something
- if (!evenAmountOfBackslashes)
+ if (not evenAmountOfBackslashes)
{
+ // uneven amount of backslashes means the user wants to escape
+ // something so we know there is a case such as '\X' or '\\\X' but
+ // we don't know yet what X is.
+ // at this point in the code, the currentChar has the value of X.
+
// slash, backslash and quote are copied as is
if (currentChar == '/' or currentChar == '\\' or currentChar == '"')
{
@@ -2557,8 +2568,8 @@ std::string json::parser::parseString()
}
else
{
- // all other characters are replaced by their respective
- // special character
+ // all other characters are replaced by their respective special
+ // character
switch (currentChar)
{
case 't':
@@ -2586,12 +2597,26 @@ std::string json::parser::parseString()
result += '\r';
break;
}
+ case 'u':
+ {
+ // \uXXXX[\uXXXX] is used for escaping unicode, which
+ // has it's own subroutine.
+ result += parseUnicodeEscape();
+ // the parsing process has brought us one step behind
+ // the unicode escape sequence:
+ // \uXXXX
+ // ^
+ // we need to go one character back or the parser would
+ // skip the character we are currently pointing at as
+ // the for-loop will decrement pos_ after this iteration
+ pos_--;
+ break;
+ }
default:
{
- error("expected one of \\, /, b, f, n, r, t behind backslash.");
+ error("expected one of \\, /, b, f, n, r, t, u behind backslash.");
}
}
- // TODO implement \uXXXX
}
}
else
@@ -2610,7 +2635,7 @@ std::string json::parser::parseString()
}
else if (currentChar != '\\')
{
- // All non-backslash characters are added to the end of the
+ // all non-backslash characters are added to the end of the
// result string. The only backslashes we want in the result
// are the ones that are escaped (which happens above).
result += currentChar;
@@ -2638,6 +2663,187 @@ std::string json::parser::parseString()
error("expected '\"'");
}
+
+
+/*!
+Turns a code point into it's UTF-8 representation.
+You should only pass numbers < 0x10ffff into this function
+(everything else is a invalid code point).
+
+@return the UTF-8 representation of the given code point
+*/
+std::string json::parser::codePointToUTF8(unsigned int codePoint) const
+{
+ // this method contains a lot of bit manipulations to
+ // build the bytes for UTF-8.
+
+ // the '(... >> S) & 0xHH'-patterns are used to retrieve
+ // certain bits from the code points.
+
+ // all static casts in this method have boundary checks
+
+ // we initialize all strings with their final length
+ // (e.g. 1 to 4 bytes) to save the reallocations.
+
+ if (codePoint <= 0x7f)
+ {
+ // it's just a ASCII compatible codePoint,
+ // so we just interpret the point as a character
+ // and return ASCII
+
+ return std::string(1, static_cast(codePoint));
+ }
+ // if true, we need two bytes to encode this as UTF-8
+ else if (codePoint <= 0x7ff)
+ {
+ // the 0xC0 enables the two most significant two bits
+ // to make this a two-byte UTF-8 character.
+ std::string result(2, static_cast(0xC0 | ((codePoint >> 6) & 0x1F)));
+ result[1] = static_cast(0x80 | (codePoint & 0x3F));
+ return result;
+ }
+ // if true, now we need three bytes to encode this as UTF-8
+ else if (codePoint <= 0xffff)
+ {
+ // the 0xE0 enables the three most significant two bits
+ // to make this a three-byte UTF-8 character.
+ std::string result(3, static_cast(0xE0 | ((codePoint >> 12) & 0x0F)));
+ result[1] = static_cast(0x80 | ((codePoint >> 6) & 0x3F));
+ result[2] = static_cast(0x80 | (codePoint & 0x3F));
+ return result;
+ }
+ // if true, we need maximal four bytes to encode this as UTF-8
+ else if (codePoint <= 0x10ffff)
+ {
+ // the 0xE0 enables the four most significant two bits
+ // to make this a three-byte UTF-8 character.
+ std::string result(4, static_cast(0xF0 | ((codePoint >> 18) & 0x07)));
+ result[1] = static_cast(0x80 | ((codePoint >> 12) & 0x3F));
+ result[2] = static_cast(0x80 | ((codePoint >> 6) & 0x3F));
+ result[3] = static_cast(0x80 | (codePoint & 0x3F));
+ return result;
+ }
+ else
+ {
+ // Can't be tested without direct access to this private method.
+ std::string errorMessage = "Invalid codePoint: ";
+ errorMessage += codePoint;
+ error(errorMessage);
+ }
+}
+
+/*!
+Parses 4 hexadecimal characters as a number.
+
+@return the value of the number the hexadecimal characters represent.
+
+@pre pos_ is pointing to the first of the 4 hexadecimal characters.
+
+@post pos_ is pointing to the character after the 4 hexadecimal characters.
+*/
+unsigned int json::parser::parse4HexCodePoint()
+{
+ const auto startPos = pos_;
+
+ // check if the remaining buffer is long enough to even hold 4 characters
+ if (pos_ + 3 >= buffer_.size())
+ {
+ error("Got end of input while parsing unicode escape sequence \\uXXXX");
+ }
+
+ // make a string that can hold the pair
+ std::string hexCode(4, ' ');
+
+ for (; pos_ < startPos + 4; pos_++)
+ {
+ // no boundary check here as we already checked above
+ char currentChar = buffer_[pos_];
+
+ // check if we have a hexadecimal character
+ if ((currentChar >= '0' and currentChar <= '9')
+ or (currentChar >= 'a' and currentChar <= 'f')
+ or (currentChar >= 'A' and currentChar <= 'F'))
+ {
+ // all is well, we have valid hexadecimal chars
+ // so we copy that char into our string
+ hexCode[pos_ - startPos] = currentChar;
+ }
+ else
+ {
+ error("Found non-hexadecimal character in unicode escape sequence!");
+ }
+ }
+ // the cast is safe as 4 hex characters can't present more than 16 bits
+ // the input to stoul was checked to contain only hexadecimal characters
+ // (see above)
+ return static_cast(std::stoul(hexCode, nullptr, 16));
+}
+
+/*!
+Parses the unicode escape codes as defined in the ECMA-404.
+The escape sequence has two forms:
+1. \uXXXX
+2. \uXXXX\uYYYY
+where X and Y are a hexadecimal character (a-zA-Z0-9).
+
+Form 1 just contains the unicode code point in the hexadecimal number XXXX.
+Form 2 is encoding a UTF-16 surrogate pair. The high surrogate is XXXX, the low
+surrogate is YYYY.
+
+@return the UTF-8 character this unicode escape sequence escaped.
+
+@pre pos_ is pointing at at the 'u' behind the first backslash.
+
+@post pos_ is pointing at the character behind the last X (or Y in form 2).
+*/
+std::string json::parser::parseUnicodeEscape()
+{
+ // jump to the first hex value
+ pos_++;
+ // parse the hex first hex values
+ unsigned int firstCodePoint = parse4HexCodePoint();
+
+ if (firstCodePoint >= 0xD800 and firstCodePoint <= 0xDBFF)
+ {
+ // we found invalid code points, which means we either have a malformed
+ // input or we found a high surrogate.
+ // we can only find out by seeing if the next character also wants to
+ // encode a unicode character (so, we have the \uXXXX\uXXXX case here).
+
+ // jump behind the next \u
+ pos_ += 2;
+ // try to parse the next hex values.
+ // the method does boundary checking for us, so no need to do that here
+ unsigned secondCodePoint = parse4HexCodePoint();
+ // ok, we have a low surrogate, check if it is a valid one
+ if (secondCodePoint >= 0xDC00 and secondCodePoint <= 0xDFFF)
+ {
+ // calculate the code point from the pair according to the spec
+ unsigned int finalCodePoint =
+ // high surrogate occupies the most significant 22 bits
+ (firstCodePoint << 10)
+ // low surrogate occupies the least significant 15 bits
+ + secondCodePoint
+ // there is still the 0xD800, 0xDC00 and 0x10000 noise in
+ // the result
+ // so we have to substract with:
+ // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00
+ - 0x35FDC00;
+
+ // we transform the calculated point into UTF-8
+ return codePointToUTF8(finalCodePoint);
+ }
+ else
+ {
+ error("missing low surrogate");
+ }
+
+ }
+ // We have Form 1, so we just interpret the XXXX as a code point
+ return codePointToUTF8(firstCodePoint);
+}
+
+
/*!
This function is called in case a \p "t" is read in the main parse function
@ref parse. In the standard, the \p "true" token is the only candidate, so the
diff --git a/src/json.cc b/src/json.cc
index 177977d7..31d709cb 100644
--- a/src/json.cc
+++ b/src/json.cc
@@ -1988,9 +1988,9 @@ json json::parser::parse()
// remember position of number's first character
const auto _firstpos_ = pos_ - 1;
- while (next() and (std::isdigit(current_) || current_ == '.'
- || current_ == 'e' || current_ == 'E'
- || current_ == '+' || current_ == '-'));
+ while (next() and (std::isdigit(current_) or current_ == '.'
+ or current_ == 'e' or current_ == 'E'
+ or current_ == '+' or current_ == '-'));
try
{
@@ -2066,7 +2066,7 @@ the error message \p msg), and the last read token.
@exception std::invalid_argument whenever the function is called
*/
-void json::parser::error(const std::string& msg)
+void json::parser::error(const std::string& msg) const
{
throw std::invalid_argument("parse error at position " +
std::to_string(pos_) + ": " + msg +
@@ -2102,7 +2102,7 @@ std::string json::parser::parseString()
{
char currentChar = buffer_[pos_];
- if (!evenAmountOfBackslashes)
+ if (not evenAmountOfBackslashes)
{
// uneven amount of backslashes means the user wants to escape
// something so we know there is a case such as '\X' or '\\\X' but
@@ -2110,9 +2110,7 @@ std::string json::parser::parseString()
// at this point in the code, the currentChar has the value of X.
// slash, backslash and quote are copied as is
- if ( currentChar == '/'
- || currentChar == '\\'
- || currentChar == '"')
+ if (currentChar == '/' or currentChar == '\\' or currentChar == '"')
{
result += currentChar;
}
@@ -2221,12 +2219,8 @@ You should only pass numbers < 0x10ffff into this function
(everything else is a invalid code point).
@return the UTF-8 representation of the given code point
-
-@pre This method isn't accessing the members of the parser
-
-@post This method isn't accessing the members of the parser
*/
-std::string json::parser::codePointToUTF8(unsigned int codePoint)
+std::string json::parser::codePointToUTF8(unsigned int codePoint) const
{
// this method contains a lot of bit manipulations to
// build the bytes for UTF-8.
@@ -2239,7 +2233,6 @@ std::string json::parser::codePointToUTF8(unsigned int codePoint)
// we initialize all strings with their final length
// (e.g. 1 to 4 bytes) to save the reallocations.
-
if (codePoint <= 0x7f)
{
// it's just a ASCII compatible codePoint,
@@ -2309,15 +2302,15 @@ unsigned int json::parser::parse4HexCodePoint()
// make a string that can hold the pair
std::string hexCode(4, ' ');
- for(; pos_ < startPos + 4; pos_++)
+ for (; pos_ < startPos + 4; pos_++)
{
// no boundary check here as we already checked above
char currentChar = buffer_[pos_];
// check if we have a hexadecimal character
- if ( (currentChar >= '0' && currentChar <= '9')
- || (currentChar >= 'a' && currentChar <= 'f')
- || (currentChar >= 'A' && currentChar <= 'F'))
+ if ((currentChar >= '0' and currentChar <= '9')
+ or (currentChar >= 'a' and currentChar <= 'f')
+ or (currentChar >= 'A' and currentChar <= 'F'))
{
// all is well, we have valid hexadecimal chars
// so we copy that char into our string
@@ -2358,8 +2351,7 @@ std::string json::parser::parseUnicodeEscape()
// parse the hex first hex values
unsigned int firstCodePoint = parse4HexCodePoint();
-
- if (firstCodePoint >= 0xD800 && firstCodePoint <= 0xDBFF)
+ if (firstCodePoint >= 0xD800 and firstCodePoint <= 0xDBFF)
{
// we found invalid code points, which means we either have a malformed
// input or we found a high surrogate.
@@ -2372,25 +2364,27 @@ std::string json::parser::parseUnicodeEscape()
// the method does boundary checking for us, so no need to do that here
unsigned secondCodePoint = parse4HexCodePoint();
// ok, we have a low surrogate, check if it is a valid one
- if (secondCodePoint >= 0xDC00 && secondCodePoint <= 0xDFFF)
+ if (secondCodePoint >= 0xDC00 and secondCodePoint <= 0xDFFF)
{
// calculate the code point from the pair according to the spec
unsigned int finalCodePoint =
- // high surrogate occupies the most significant 22 bits
- (firstCodePoint << 10)
- // low surrogate occupies the least significant 15 bits
- + secondCodePoint
- // there is still the 0xD800, 0xDC00 and 0x10000 noise in
- // the result
- // so we have to substract with:
- // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00
- - 0x35FDC00;
+ // high surrogate occupies the most significant 22 bits
+ (firstCodePoint << 10)
+ // low surrogate occupies the least significant 15 bits
+ + secondCodePoint
+ // there is still the 0xD800, 0xDC00 and 0x10000 noise in
+ // the result
+ // so we have to substract with:
+ // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00
+ - 0x35FDC00;
// we transform the calculated point into UTF-8
return codePointToUTF8(finalCodePoint);
}
else
+ {
error("missing low surrogate");
+ }
}
// We have Form 1, so we just interpret the XXXX as a code point
diff --git a/src/json.h b/src/json.h
index 126f96a3..cb158bcc 100644
--- a/src/json.h
+++ b/src/json.h
@@ -418,11 +418,11 @@ class json
/// read the next character, stripping whitespace
bool next();
/// raise an exception with an error message
- inline void error(const std::string&) __attribute__((noreturn));
+ inline void error(const std::string&) const __attribute__((noreturn));
/// parse a quoted string
inline std::string parseString();
/// transforms a unicode codepoint to it's UTF-8 presentation
- std::string codePointToUTF8(unsigned int codePoint);
+ std::string codePointToUTF8(unsigned int codePoint) const;
/// parses 4 hex characters that represent a unicode code point
inline unsigned int parse4HexCodePoint();
/// parses \uXXXX[\uXXXX] unicode escape characters