json: Support parsing objects

robinlinden · Jan 14, 2025 · 3757153 · 3757153
1 parent 38639e2
commit 3757153
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Showing 2 changed files with 77 additions and 1 deletion.
diff --git a/json/json.h b/json/json.h
@@ -125,11 +125,62 @@ class Parser {
                 return parse_null();
             case '[':
                 return parse_array();
+            case '{':
+                return parse_object();
             default:
                 return std::nullopt;
         }
     }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
+    constexpr std::optional<Value> parse_object() {
+        std::ignore = consume(); // '{'
+        if (peek() == '}') {
+            std::ignore = consume();
+            return Object{};
+        }
+
+        Object object;
+        while (true) {
+            skip_whitespace();
+
+            auto key = parse_string();
+            if (!key) {
+                return std::nullopt;
+            }
+
+            skip_whitespace();
+            if (consume() != ':') {
+                return std::nullopt;
+            }
+
+            auto value = parse_value();
+            if (!value) {
+                return std::nullopt;
+            }
+
+            object.values[std::get<std::string>(*std::move(key))] = *std::move(value);
+            skip_whitespace();
+
+            auto c = peek();
+            if (!c) {
+                return std::nullopt;
+            }
+
+            if (*c == ',') {
+                std::ignore = consume();
+                continue;
+            }
+
+            if (*c == '}') {
+                std::ignore = consume();
+                return object;
+            }
+
+            return std::nullopt;
+        }
+    }
+
     // NOLINTNEXTLINE(misc-no-recursion)
     constexpr std::optional<Value> parse_array() {
         std::ignore = consume(); // '['
@@ -206,7 +257,10 @@ class Parser {
 
     constexpr std::optional<Value> parse_string() {
         std::string value;
-        std::ignore = consume(); // '"'
+        if (consume() != '"') {
+            return std::nullopt;
+        }
+
         while (auto c = consume()) {
             if (*c == '"') {
                 return value;

diff --git a/json/json_test.cpp b/json/json_test.cpp
@@ -85,5 +85,27 @@ int main() {
         a.expect_eq(json::parse("[null,"), std::nullopt);
     });
 
+    s.add_test("object", [](etest::IActions &a) {
+        a.expect_eq(json::parse("{}"), Value{json::Object{}});
+        a.expect_eq(json::parse(R"({"key": "value"})"), Value{json::Object{{{"key", Value{"value"}}}}});
+        a.expect_eq(json::parse(R"({"key": "value", "key2": "value2"})"),
+                Value{json::Object{{{"key", Value{"value"}}, {"key2", Value{"value2"}}}}});
+        a.expect_eq(json::parse(R"({"key": true, "key2": "value2", "key3": false})"),
+                Value{json::Object{{{"key", Value{true}}, {"key2", Value{"value2"}}, {"key3", Value{false}}}}});
+
+        a.expect_eq(json::parse(R"({"key": {"key": "value"}})"),
+                Value{json::Object{{{"key", Value{json::Object{{{"key", Value{"value"}}}}}}}}});
+
+        a.expect_eq(json::parse("{"), std::nullopt);
+        a.expect_eq(json::parse("{blah"), std::nullopt);
+        a.expect_eq(json::parse("{null"), std::nullopt);
+        a.expect_eq(json::parse(R"({"key")"), std::nullopt);
+        a.expect_eq(json::parse(R"({"key":)"), std::nullopt);
+        a.expect_eq(json::parse(R"({"key":asdf)"), std::nullopt);
+        a.expect_eq(json::parse(R"({"key":true)"), std::nullopt);
+        a.expect_eq(json::parse(R"({"key":true,)"), std::nullopt);
+        a.expect_eq(json::parse(R"({"key":true})"), Value{json::Object{{{"key", Value{true}}}}});
+    });
+
     return s.run();
 }