feat: Add example json_split in cpp

NAMESPACE

@@ -13,3 +13,4 @@ export(stop)
 export(stopifnot)
 export(warning)
 export(with_loggit)
+useDynLib(loggit2, .registration=TRUE)

R/loggit.R

@@ -1,3 +1,6 @@
+#' @useDynLib loggit2, .registration=TRUE
+NULL
+
 #' Log entries to file
 #'
 #' Log entries to a [ndjson](https://github.com/ndjson) log file, defined by [set_logfile()].

src/.gitignore

@@ -0,0 +1,3 @@
+*.o
+*.so
+*.dll

src/split_json.cpp

@@ -0,0 +1,43 @@
+#include <R.h>
+#include <Rinternals.h>
+#include <vector>
+#include <string>
+
+extern "C" SEXP splitString(SEXP strSEXP) {
+    const char* str = CHAR(STRING_ELT(strSEXP, 0));
+    std::vector<std::string> result;
+    std::string token;
+    bool inQuotes = false;
+    int backslashCount = 0;
+
+    for (int i = 0; str[i] != '\0'; ++i) {
+        char ch = str[i];
+        if (ch == '\\' && !inQuotes) {
+            backslashCount++;
+            token += ch;
+        } else if (ch == '"' && (backslashCount % 2 == 0)) {
+            inQuotes = !inQuotes;
+            token += ch;
+            backslashCount = 0;
+        } else if ((ch == ',' || ch == ':') && !inQuotes) {
+            result.push_back(token);
+            token.clear();
+            backslashCount = 0;
+        } else {
+            token += ch;
+            backslashCount = 0;
+        }
+    }
+
+    if (!token.empty()) {
+        result.push_back(token);
+    }
+
+    SEXP ans = PROTECT(allocVector(STRSXP, result.size()));
+    for (size_t j = 0; j < result.size(); ++j) {
+        SET_STRING_ELT(ans, j, mkChar(result[j].c_str()));
+    }
+
+    UNPROTECT(1);
+    return ans;
+}