Revert "Death to C++"

This reverts commit 066ac22605.

vendor/lunasvg/source/svgparserutils.h

@@ -0,0 +1,210 @@
+#ifndef LUNASVG_SVGPARSERUTILS_H
+#define LUNASVG_SVGPARSERUTILS_H
+
+#include <cmath>
+#include <string_view>
+#include <limits>
+
+namespace lunasvg {
+
+constexpr bool IS_NUM(int cc) { return cc >= '0' && cc <= '9'; }
+constexpr bool IS_ALPHA(int cc) { return (cc >= 'a' && cc <= 'z') || (cc >= 'A' && cc <= 'Z'); }
+constexpr bool IS_WS(int cc) { return cc == ' ' || cc == '\t' || cc == '\n' || cc == '\r'; }
+
+constexpr void stripLeadingSpaces(std::string_view& input)
+{
+    while(!input.empty() && IS_WS(input.front())) {
+        input.remove_prefix(1);
+    }
+}
+
+constexpr void stripTrailingSpaces(std::string_view& input)
+{
+    while(!input.empty() && IS_WS(input.back())) {
+        input.remove_suffix(1);
+    }
+}
+
+constexpr void stripLeadingAndTrailingSpaces(std::string_view& input)
+{
+    stripLeadingSpaces(input);
+    stripTrailingSpaces(input);
+}
+
+constexpr bool skipOptionalSpaces(std::string_view& input)
+{
+    while(!input.empty() && IS_WS(input.front()))
+        input.remove_prefix(1);
+    return !input.empty();
+}
+
+constexpr bool skipOptionalSpacesOrDelimiter(std::string_view& input, char delimiter)
+{
+    if(!input.empty() && !IS_WS(input.front()) && delimiter != input.front())
+        return false;
+    if(skipOptionalSpaces(input)) {
+        if(delimiter == input.front()) {
+            input.remove_prefix(1);
+            skipOptionalSpaces(input);
+        }
+    }
+
+    return !input.empty();
+}
+
+constexpr bool skipOptionalSpacesOrComma(std::string_view& input)
+{
+    return skipOptionalSpacesOrDelimiter(input, ',');
+}
+
+constexpr bool skipDelimiterAndOptionalSpaces(std::string_view& input, char delimiter)
+{
+    if(!input.empty() && input.front() == delimiter) {
+        input.remove_prefix(1);
+        skipOptionalSpaces(input);
+        return true;
+    }
+
+    return false;
+}
+
+constexpr bool skipDelimiter(std::string_view& input, char delimiter)
+{
+    if(!input.empty() && input.front() == delimiter) {
+        input.remove_prefix(1);
+        return true;
+    }
+
+    return false;
+}
+
+constexpr bool skipString(std::string_view& input, std::string_view value)
+{
+    if(input.size() >= value.size() && value == input.substr(0, value.size())) {
+        input.remove_prefix(value.size());
+        return true;
+    }
+
+    return false;
+}
+
+constexpr bool isIntegralDigit(char ch, int base)
+{
+    if(IS_NUM(ch))
+        return ch - '0' < base;
+    if(IS_ALPHA(ch))
+        return (ch >= 'a' && ch < 'a' + base - 10) || (ch >= 'A' && ch < 'A' + base - 10);
+    return false;
+}
+
+constexpr int toIntegralDigit(char ch)
+{
+    if(IS_NUM(ch))
+        return ch - '0';
+    if(ch >= 'a')
+        return ch - 'a' + 10;
+    return ch - 'A' + 10;
+}
+
+template<typename T>
+inline bool parseInteger(std::string_view& input, T& integer, int base = 10)
+{
+    constexpr bool isSigned = std::numeric_limits<T>::is_signed;
+    constexpr T intMax = std::numeric_limits<T>::max();
+    const T maxMultiplier = intMax / static_cast<T>(base);
+
+    T value = 0;
+    bool isNegative = false;
+
+    if(!input.empty() && input.front() == '+') {
+        input.remove_prefix(1);
+    } else if(!input.empty() && isSigned && input.front() == '-') {
+        input.remove_prefix(1);
+        isNegative = true;
+    }
+
+    if(input.empty() || !isIntegralDigit(input.front(), base))
+        return false;
+    do {
+        const int digitValue = toIntegralDigit(input.front());
+        if(value > maxMultiplier || (value == maxMultiplier && static_cast<T>(digitValue) > (intMax % static_cast<T>(base)) + isNegative))
+            return false;
+        value = static_cast<T>(base) * value + static_cast<T>(digitValue);
+        input.remove_prefix(1);
+    } while(!input.empty() && isIntegralDigit(input.front(), base));
+
+    using SignedType = typename std::make_signed<T>::type;
+    if(isNegative)
+        integer = -static_cast<SignedType>(value);
+    else
+        integer = value;
+    return true;
+}
+
+template<typename T>
+inline bool parseNumber(std::string_view& input, T& number)
+{
+    constexpr T maxValue = std::numeric_limits<T>::max();
+    T integer = 0;
+    T fraction = 0;
+    int exponent = 0;
+    int sign = 1;
+    int expsign = 1;
+
+    if(!input.empty() && input.front() == '+') {
+        input.remove_prefix(1);
+    } else if(!input.empty() && input.front() == '-') {
+        input.remove_prefix(1);
+        sign = -1;
+    }
+
+    if(input.empty() || (!IS_NUM(input.front()) && input.front() != '.'))
+        return false;
+    if(IS_NUM(input.front())) {
+        do {
+            integer = static_cast<T>(10) * integer + (input.front() - '0');
+            input.remove_prefix(1);
+        } while(!input.empty() && IS_NUM(input.front()));
+    }
+
+    if(!input.empty() && input.front() == '.') {
+        input.remove_prefix(1);
+        if(input.empty() || !IS_NUM(input.front()))
+            return false;
+        T divisor = static_cast<T>(1);
+        do {
+            fraction = static_cast<T>(10) * fraction + (input.front() - '0');
+            divisor *= static_cast<T>(10);
+            input.remove_prefix(1);
+        } while(!input.empty() && IS_NUM(input.front()));
+        fraction /= divisor;
+    }
+
+    if(input.size() > 1 && (input[0] == 'e' || input[0] == 'E')
+        && (input[1] != 'x' && input[1] != 'm'))
+    {
+        input.remove_prefix(1);
+        if(!input.empty() && input.front() == '+')
+            input.remove_prefix(1);
+        else if(!input.empty() && input.front() == '-') {
+            input.remove_prefix(1);
+            expsign = -1;
+        }
+
+        if(input.empty() || !IS_NUM(input.front()))
+            return false;
+        do {
+            exponent = 10 * exponent + (input.front() - '0');
+            input.remove_prefix(1);
+        } while(!input.empty() && IS_NUM(input.front()));
+    }
+
+    number = sign * (integer + fraction);
+    if(exponent)
+        number *= static_cast<T>(std::pow(10.0, expsign * exponent));
+    return number >= -maxValue && number <= maxValue;
+}
+
+} // namespace lunasvg
+
+#endif // LUNASVG_SVGPARSERUTILS_H