diff --git a/mlir/include/mlir/Dialect/SparseTensor/IR/SparseTensor.h b/mlir/include/mlir/Dialect/SparseTensor/IR/SparseTensor.h
--- a/mlir/include/mlir/Dialect/SparseTensor/IR/SparseTensor.h
+++ b/mlir/include/mlir/Dialect/SparseTensor/IR/SparseTensor.h
@@ -50,6 +50,33 @@
 // Dimension level types.
 //
 
+/// Returns string representation of the given dimension level type.
+inline StringRef toString(DimLevelType dlt) {
+  switch (dlt) {
+  case DimLevelType::Undef:
+    return "\"undef\"";
+  case DimLevelType::Dense:
+    return "\"dense\"";
+  case DimLevelType::Compressed:
+    return "\"compressed\"";
+  case DimLevelType::CompressedNu:
+    return "\"compressed-nu\"";
+  case DimLevelType::CompressedNo:
+    return "\"compressed-no\"";
+  case DimLevelType::CompressedNuNo:
+    return "\"compressed-nu-no\"";
+  case DimLevelType::Singleton:
+    return "\"singleton\"";
+  case DimLevelType::SingletonNu:
+    return "\"singleton-nu\"";
+  case DimLevelType::SingletonNo:
+    return "\"singleton-no\"";
+  case DimLevelType::SingletonNuNo:
+    return "\"singleton-nu-no\"";
+  }
+  llvm_unreachable("unknown DimLevelType");
+}
+
 // MSVC does not allow this function to be constexpr, because
 // `SparseTensorEncodingAttr::operator bool` isn't declared constexpr.
 // And therefore all functions calling it cannot be constexpr either.
diff --git a/mlir/lib/Dialect/SparseTensor/IR/SparseTensorDialect.cpp b/mlir/lib/Dialect/SparseTensor/IR/SparseTensorDialect.cpp
--- a/mlir/lib/Dialect/SparseTensor/IR/SparseTensorDialect.cpp
+++ b/mlir/lib/Dialect/SparseTensor/IR/SparseTensorDialect.cpp
@@ -160,39 +160,7 @@
   // Print the struct-like storage in dictionary fashion.
   printer << "<{ dimLevelType = [ ";
   for (unsigned i = 0, e = getDimLevelType().size(); i < e; i++) {
-    switch (getDimLevelType()[i]) {
-    case DimLevelType::Undef:
-      // TODO: should probably raise an error instead of printing it...
-      printer << "\"undef\"";
-      break;
-    case DimLevelType::Dense:
-      printer << "\"dense\"";
-      break;
-    case DimLevelType::Compressed:
-      printer << "\"compressed\"";
-      break;
-    case DimLevelType::CompressedNu:
-      printer << "\"compressed-nu\"";
-      break;
-    case DimLevelType::CompressedNo:
-      printer << "\"compressed-no\"";
-      break;
-    case DimLevelType::CompressedNuNo:
-      printer << "\"compressed-nu-no\"";
-      break;
-    case DimLevelType::Singleton:
-      printer << "\"singleton\"";
-      break;
-    case DimLevelType::SingletonNu:
-      printer << "\"singleton-nu\"";
-      break;
-    case DimLevelType::SingletonNo:
-      printer << "\"singleton-no\"";
-      break;
-    case DimLevelType::SingletonNuNo:
-      printer << "\"singleton-nu-no\"";
-      break;
-    }
+    printer << toString(getDimLevelType()[i]);
     if (i != e - 1)
       printer << ", ";
   }