config/lua: add ExpressionVec2, allow using a table for vec2 rules (#14197)

1 files changed, 42 insertions, 0 deletions

diff --git a/src/helpers/math/Expression.cpp b/src/helpers/math/Expression.cpp
index 3c0bee91..2289b85e 100644
--- a/src/helpers/math/Expression.cpp
+++ b/src/helpers/math/Expression.cpp
@@ -2,8 +2,50 @@
 #include "muParser.h"
 #include "../../debug/log/Logger.hpp"
 
+#include <cctype>
+#include <format>
+
 using namespace Math;
 
+static std::string_view trimExprView(std::string_view s) {
+    while (!s.empty() && std::isspace(static_cast<unsigned char>(s.front())))
+        s.remove_prefix(1);
+
+    while (!s.empty() && std::isspace(static_cast<unsigned char>(s.back())))
+        s.remove_suffix(1);
+
+    return s;
+}
+
+bool SExpressionVec2::empty() const {
+    return x.empty() || y.empty();
+}
+
+std::string SExpressionVec2::toString() const {
+    if (empty())
+        return "";
+
+    return std::format("{} {}", x, y);
+}
+
+std::expected<SExpressionVec2, std::string> Math::parseExpressionVec2(std::string_view raw) {
+    raw = trimExprView(raw);
+    if (raw.empty())
+        return SExpressionVec2{};
+
+    const auto spacePos = raw.find_first_of(" \t\n\r\f\v");
+    if (spacePos == std::string_view::npos)
+        return std::unexpected("expression vec2 requires two expressions separated by whitespace");
+
+    auto lhs = trimExprView(raw.substr(0, spacePos));
+    auto rhs = trimExprView(raw.substr(spacePos + 1));
+
+    if (lhs.empty() || rhs.empty())
+        return std::unexpected("expression vec2 requires two non-empty expressions");
+
+    return SExpressionVec2{std::string{lhs}, std::string{rhs}};
+}
+
 CExpression::CExpression() : m_parser(makeUnique<mu::Parser>()) {
     ;
 }