inline std::string getSourcePositionText()

in src/RStuff/RUtil.h [270:298]

• 29 lines of code
• 12 McCabe index (conditional complexity)

inline std::string getSourcePositionText(SEXP srcref, bool onlyFirstLine) {
  if (TYPEOF(srcref) != INTSXP || Rf_length(srcref) < 6) return "";
  ShieldSEXP srcfile = Rf_getAttrib(srcref, RI->srcfileAttr);
  if (srcfile == R_NilValue) return "";
  VirtualFileInfoPtr virtualFile = Rf_getAttrib(srcfile, RI->virtualFilePtrAttr);
  if (virtualFile.isNull() || virtualFile->isGenerated) return "";
  ShieldSEXP lines = srcfile["lines"];
  if (lines.type() != STRSXP) return "";
  if (onlyFirstLine) {
    return stringEltUTF8(lines, INTEGER(srcref)[0] - 1);
  } else {
    std::string first = stringEltUTF8(lines, INTEGER(srcref)[0] - 1);
    int startLine = INTEGER(srcref)[0] - 1;
    int endLine = INTEGER(srcref)[2] - 1;
    int startOffset = INTEGER(srcref)[4] - 1;
    int endOffset = INTEGER(srcref)[5] - 1;
    std::string text;
    for (int i = startLine; i <= endLine; ++i) {
      int start = i == startLine ? startOffset : 0;
      if (i == endLine) {
        text += asStringUTF8(RI->substring(lines[i], start + 1, endOffset + 1));
      } else {
        text += asStringUTF8(RI->substring(lines[i], start + 1));
      }
      if (i != endLine) text += '\n';
    }
    return text;
  }
}