[ggj] feat: add Value interface and PrimitiveValue set-up

src/main/java/com/google/api/generator/engine/ast/PrimitiveValue.java

@@ -0,0 +1,79 @@
+// Copyright 2020 Google LLC
+//
+// 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.
+
+package com.google.api.generator.engine.ast;
+
+import com.google.api.generator.engine.lexicon.Literal;
+import com.google.auto.value.AutoValue;
+
+@AutoValue
+public abstract class PrimitiveValue implements Value {
+  static class TypeMismatchException extends RuntimeException {
+    public TypeMismatchException(String errorMessage) {
+      super(errorMessage);
+    }
+  }
+
+  // TODO(miraleung):F Handle object types.
+  public abstract TypeNode type();
+
+  public abstract String value();
+
+  public static Builder builder() {
+    return new AutoValue_PrimitiveValue.Builder();
+  }
+
+  @AutoValue.Builder
+  public abstract static class Builder {
+    public abstract Builder setType(TypeNode type);
+
+    public abstract Builder setValue(String value);
+
+    abstract PrimitiveValue autoBuild();
+
+    public PrimitiveValue build() throws TypeMismatchException {
+      // TODO(unsupported): byte, short, char, array initialization.
+      // TODO(miraleung): Object type checking?
+      PrimitiveValue primitiveValue = autoBuild();
+      TypeNode type = primitiveValue.type();
+      String value = primitiveValue.value();
+      if (!typeMatchesValue(type, value)) {
+        throw new TypeMismatchException(
+            String.format("Type %s does not match value %s", type.typeKind(), value));
+      }
+      return primitiveValue;
+    }
+
+    private static boolean typeMatchesValue(TypeNode type, String value) {
+      switch (type.typeKind()) {
+        case INT:
+          return Literal.isIntegerLiteral(value);
+        case LONG:
+          return Literal.isLongLiteral(value);
+        case FLOAT:
+          return Literal.isFloatLiteral(value);
+        case DOUBLE:
+          return Literal.isDoubleLiteral(value);
+        case BOOLEAN:
+          return Literal.isBooleanLiteral(value);
+        case OBJECT: // Fall through.
+        case BYTE: // Fall through.
+        case CHAR: // Fall through.
+        case SHORT: // Fall through.
+        default:
+      }
+      return false;
+    }
+  }
+}

src/main/java/com/google/api/generator/engine/ast/Value.java

@@ -0,0 +1,17 @@
+// Copyright 2020 Google LLC
+//
+// 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.
+
+package com.google.api.generator.engine.ast;
+
+public interface Value {}

src/test/java/com/google/api/generator/engine/ast/BUILD.bazel

@@ -2,6 +2,7 @@ package(default_visibility = ["//visibility:public"])
 
 TESTS = [
     "IdentifierNodeTest",
+    "PrimitiveValueTest",
 ]
 
 filegroup(

src/test/java/com/google/api/generator/engine/ast/PrimitiveValueTest.java

@@ -0,0 +1,64 @@
+// Copyright 2020 Google LLC
+//
+// 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.
+
+package com.google.api.generator.engine.ast;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import com.google.api.generator.engine.ast.PrimitiveValue.TypeMismatchException;
+import com.google.api.generator.engine.ast.TypeNode.TypeKind;
+import org.junit.Test;
+
+public class PrimitiveValueTest {
+  @Test
+  public void createPrimitiveValue_basic() {
+    assertValidValue(TypeKind.INT, "3");
+    assertValidValue(TypeKind.BOOLEAN, "false");
+    assertValidValue(TypeKind.LONG, "123");
+    assertValidValue(TypeKind.FLOAT, "123.f");
+    assertValidValue(TypeKind.DOUBLE, "123e10");
+  }
+
+  @Test
+  public void createPrimitiveValue_invalid() {
+    assertInvalidValue(TypeKind.INT, "123.f");
+    assertInvalidValue(TypeKind.INT, "false");
+    assertInvalidValue(TypeKind.BOOLEAN, "False");
+    assertInvalidValue(TypeKind.FLOAT, "asdfg");
+  }
+
+  @Test
+  public void createPrimitiveValue_unsupported() {
+    assertInvalidValue(TypeKind.BYTE, "0x2");
+    assertInvalidValue(TypeKind.SHORT, "1");
+    assertInvalidValue(TypeKind.CHAR, "a");
+  }
+
+  private static void assertValidValue(TypeKind typeKind, String value) {
+    TypeNode type = TypeNode.builder().setTypeKind(typeKind).build();
+    PrimitiveValue primitiveValue = PrimitiveValue.builder().setType(type).setValue(value).build();
+    assertThat(primitiveValue.value()).isEqualTo(value);
+    assertThat(primitiveValue.type()).isEqualTo(type);
+  }
+
+  private void assertInvalidValue(TypeKind typeKind, String value) {
+    TypeNode type = TypeNode.builder().setTypeKind(typeKind).build();
+    assertThrows(
+        TypeMismatchException.class,
+        () -> {
+          PrimitiveValue.builder().setType(type).setValue(value).build();
+        });
+  }
+}