JSON: Add simple printing and creation

src/support/CMakeLists.txt

@@ -8,6 +8,7 @@ set(support_SOURCES
  dfa_minimization.cpp
  file.cpp
  istring.cpp
+ json.cpp
  path.cpp
  safe_integer.cpp
  threads.cpp

src/support/json.cpp

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2024 WebAssembly Community Group participants
+ *
+ * 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
+ *
+ * http://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 "support/json.h"
+
+namespace json {
+
+void Value::stringify(std::ostream& os, bool pretty) {
+ if (isString()) {
+ // TODO: escaping
+ os << '"' << getCString() << '"';
+ } else if (isArray()) {
+ os << '[';
+ auto first = true;
+ for (auto& item : getArray()) {
+ if (first) {
+ first = false;
+ } else {
+ // TODO pretty whitespace
+ os << ',';
+ }
+ item->stringify(os, pretty);
+ }
+ os << ']';
+ } else {
+ WASM_UNREACHABLE("TODO: stringify all of JSON");
+ }
+}
+
+} // namespace json

src/support/json.h

@@ -54,6 +54,8 @@ struct Value {
  Ref& operator[](IString x) { return (*this->get())[x]; }
  };
 
+ template<typename T> static Ref make(T t) { return Ref(new Value(t)); }
+
  enum Type {
  String = 0,
  Number = 1,

test/gtest/CMakeLists.txt

@@ -4,6 +4,7 @@ include_directories(../../src/wasm)
 set(unittest_SOURCES
  cfg.cpp
  dfa_minimization.cpp
+ json.cpp
  lattices.cpp
  possible-contents.cpp
  printing.cpp

test/gtest/json.cpp

@@ -0,0 +1,16 @@
+#include "support/json.h"
+#include "gtest/gtest.h"
+
+using JSONTest = ::testing::Test;
+
+TEST_F(JSONTest, Stringify) {
+ // TODO: change the API to not require a copy
+ auto input = "[\"hello\",\"world\"]";
+ auto* copy = strdup(input);
+ json::Value value;
+ value.parse(copy);
+ std::stringstream ss;
+ value.stringify(ss);
+ EXPECT_EQ(ss.str(), input);
+ free(copy);
+}