1 files changed, 84 insertions, 0 deletions
diff --git a/src/ui/stream.cc b/src/ui/stream.cc
new file mode 100644
index 0000000..74e34be
--- /dev/null
+++ b/src/ui/stream.cc
@@ -0,0 +1,84 @@
+// Copyright 2021 Benjamin Barenblat
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+#include "src/ui/stream.h"
+
+#include <assert.h>
+
+#include <istream>
+#include <memory>
+#include <ostream>
+#include <string>
+
+#include "src/error.h"
+#include "src/language.h"
+#include "src/parser_driver.h"
+#include "third_party/abseil/absl/strings/str_join.h"
+
+namespace ec {
+
+namespace {
+
+std::string ReadAll(std::istream& in) noexcept {
+  std::string result;
+  int bytes_read = 0;
+  while (in.good()) {
+    result.append(4096, '\0');
+    in.read(result.data() + bytes_read, 4096);
+    bytes_read += in.gcount();
+  }
+  assert(bytes_read <= result.size());
+  result.resize(bytes_read);
+  return result;
+}
+
+void ShowState(const State& state, std::ostream& out) noexcept {
+  if (state.stack.empty()) {
+    return;
+  }
+  out << absl::StrJoin(state.stack, " ", FormatStackElement) << '\n';
+}
+
+}  // namespace
+
+int LineUi::Main() noexcept {
+  State state;
+  while (in_.good()) {
+    std::string line;
+    std::getline(in_, line);
+    try {
+      EvaluateAll(ParseFromString(line), state);
+    } catch (const Error& e) {
+      std::cerr << "ec: " << e.what() << '\n';
+      return 1;
+    }
+  }
+  ShowState(state, out_);
+  return 0;
+}
+
+int StreamUi::Main() noexcept {
+  State state;
+  std::string program = ReadAll(in_);
+  try {
+    EvaluateAll(ParseFromString(program), state);
+  } catch (const Error& e) {
+    std::cerr << "ec: " << e.what() << '\n';
+    return 1;
+  }
+  ShowState(state, out_);
+  return 0;
+}
+
+}  // namespace ec