feat(objectionary#329): Add CheckCast ast node

src/main/java/org/eolang/opeo/ast/CheckCast.java

@@ -0,0 +1,103 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2023 Objectionary.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.eolang.opeo.ast;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.eolang.jeo.representation.directives.DirectivesData;
+import org.eolang.jeo.representation.xmir.HexString;
+import org.eolang.jeo.representation.xmir.XmlNode;
+import org.eolang.opeo.compilation.Parser;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+import org.xembly.Directive;
+import org.xembly.Directives;
+
+/**
+ * Check if the value is of the given type.
+ * @since 0.5
+ */
+public final class CheckCast implements AstNode, Typed {
+
+    /**
+     * Type to cast to.
+     */
+    private final Type type;
+
+    /**
+     * Value to cast.
+     */
+    private final AstNode value;
+
+    public CheckCast(final XmlNode node, final Parser parser) {
+        this(CheckCast.xtype(node), CheckCast.xvalue(node, parser));
+    }
+
+    private static AstNode xvalue(final XmlNode node, final Parser parser) {
+        return parser.parse(
+            node.children().findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("CheckCast should have a child."))
+        );
+    }
+
+    private static Type xtype(final XmlNode node) {
+        return Type.getType(
+            new HexString(
+                node.children().findFirst().orElseThrow(
+                    () -> new IllegalArgumentException(
+                        "CheckCast should have a first child for the type."
+                    )
+                ).text()
+            ).decode()
+        );
+    }
+
+
+    public CheckCast(final Type type, final AstNode value) {
+        this.type = type;
+        this.value = value;
+    }
+
+    @Override
+    public Iterable<Directive> toXmir() {
+        return new Directives().add("o").attr("base", "cast")
+            .append(new DirectivesData(this.type))
+            .append(this.value.toXmir())
+            .up();
+    }
+
+    @Override
+    public List<AstNode> opcodes() {
+        final List<AstNode> res = new ArrayList<>(1);
+        res.addAll(this.value.opcodes());
+        res.add(new Opcode(Opcodes.CHECKCAST, this.type));
+        return res;
+    }
+
+    @Override
+    public Type type() {
+        return this.type;
+    }
+}

src/main/java/org/eolang/opeo/ast/Opcode.java

@@ -27,6 +27,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
 import lombok.EqualsAndHashCode;

src/test/java/org/eolang/opeo/ast/CheckCastTest.java

@@ -0,0 +1,90 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016-2023 Objectionary.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.eolang.opeo.ast;
+
+import org.eolang.jeo.representation.xmir.XmlNode;
+import org.eolang.opeo.SameXml;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+import org.xembly.ImpossibleModificationException;
+import org.xembly.Xembler;
+
+/**
+ * Test case for {@link CheckCast}.
+ * @since 0.5
+ */
+class CheckCastTest {
+
+    /**
+     * XMIR representation of the CheckCast.
+     */
+    private static final String XMIR = String.join(
+        "\n",
+        "<o base='cast'>",
+        "   <o base='type' data='bytes'>4A</o>",
+        "   <o base='int' data='bytes'>00 00 00 00 00 00 00 03</o>",
+        "</o>"
+    );
+
+    @Test
+    void convertsCheckCastToXmir() throws ImpossibleModificationException {
+        MatcherAssert.assertThat(
+            "Can't convert CheckCast to XMIR",
+            new Xembler(
+                new CheckCast(
+                    Type.LONG_TYPE,
+                    new Literal(3)
+                ).toXmir()
+            ).xml(),
+            new SameXml(CheckCastTest.XMIR)
+        );
+    }
+
+    @Test
+    void createsCheckCastFromXmir() {
+        MatcherAssert.assertThat(
+            "Can't parse CheckCast type from XMIR",
+            new CheckCast(new XmlNode(CheckCastTest.XMIR), n -> new Literal(3)).type(),
+            Matchers.equalTo(Type.LONG_TYPE)
+        );
+    }
+
+    @Test
+    void transformsToOpcodes() {
+        final Type type = Type.INT_TYPE;
+        MatcherAssert.assertThat(
+            "Can't transform CheckCast to opcodes",
+            new CheckCast(type, new Literal((byte) 3)).opcodes(),
+            Matchers.hasItems(
+                new Opcode(Opcodes.BIPUSH, (byte) 3),
+                new Opcode(Opcodes.CHECKCAST, type)
+            )
+        );
+    }
+
+
+}