Support CoreML for macOS (#151)

sherpa-onnx/csrc/provider.cc

@@ -0,0 +1,29 @@
+// sherpa-onnx/csrc/provider.cc
+//
+// Copyright (c)  2023  Xiaomi Corporation
+
+#include "sherpa-onnx/csrc/provider.h"
+
+#include <algorithm>
+#include <cctype>
+
+#include "sherpa-onnx/csrc/macros.h"
+
+namespace sherpa_onnx {
+
+Provider StringToProvider(std::string s) {
+  std::transform(s.cbegin(), s.cend(), s.begin(),
+                 [](unsigned char c) { return std::tolower(c); });
+  if (s == "cpu") {
+    return Provider::kCPU;
+  } else if (s == "cuda") {
+    return Provider::kCUDA;
+  } else if (s == "coreml") {
+    return Provider::kCoreML;
+  } else {
+    SHERPA_ONNX_LOGE("Unsupported string: %s. Fallback to cpu", s.c_str());
+    return Provider::kCPU;
+  }
+}
+
+}  // namespace sherpa_onnx