Initial commit

src/main/java/chocopy/common/astnodes/Node.java

@@ -0,0 +1,204 @@
+package chocopy.common.astnodes;
+
+import chocopy.common.analysis.NodeAnalyzer;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.module.paramnames.ParameterNamesModule;
+import java_cup.runtime.ComplexSymbolFactory.Location;
+
+import java.io.IOException;
+
+/**
+ * Root of the AST class hierarchy.  Every node has a left and right
+ * location, indicating the start and end of the represented construct
+ * in the source text.
+ * <p>
+ * Every node can be marked with an error message, which serves two purposes:
+ * 1. It indicates that an error message has been issued for this
+ * Node, allowing tne program to reduce cascades of error
+ * messages.
+ * 2. It aids in debugging by making it convenient to see which
+ * Nodes have caused an error.
+ */
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME,
+        include = JsonTypeInfo.As.EXISTING_PROPERTY,
+        property = "kind")
+/* List of all concrete subclasses of Node. */
+@JsonSubTypes({
+        @JsonSubTypes.Type(AssignStmt.class),
+        @JsonSubTypes.Type(BinaryExpr.class),
+        @JsonSubTypes.Type(BooleanLiteral.class),
+        @JsonSubTypes.Type(CallExpr.class),
+        @JsonSubTypes.Type(ClassDef.class),
+        @JsonSubTypes.Type(ClassType.class),
+        @JsonSubTypes.Type(CompilerError.class),
+        @JsonSubTypes.Type(Errors.class),
+        @JsonSubTypes.Type(ExprStmt.class),
+        @JsonSubTypes.Type(ForStmt.class),
+        @JsonSubTypes.Type(FuncDef.class),
+        @JsonSubTypes.Type(GlobalDecl.class),
+        @JsonSubTypes.Type(Identifier.class),
+        @JsonSubTypes.Type(IfExpr.class),
+        @JsonSubTypes.Type(IfStmt.class),
+        @JsonSubTypes.Type(IndexExpr.class),
+        @JsonSubTypes.Type(IntegerLiteral.class),
+        @JsonSubTypes.Type(ListExpr.class),
+        @JsonSubTypes.Type(ListType.class),
+        @JsonSubTypes.Type(MemberExpr.class),
+        @JsonSubTypes.Type(MethodCallExpr.class),
+        @JsonSubTypes.Type(NoneLiteral.class),
+        @JsonSubTypes.Type(NonLocalDecl.class),
+        @JsonSubTypes.Type(Program.class),
+        @JsonSubTypes.Type(ReturnStmt.class),
+        @JsonSubTypes.Type(StringLiteral.class),
+        @JsonSubTypes.Type(TypedVar.class),
+        @JsonSubTypes.Type(UnaryExpr.class),
+        @JsonSubTypes.Type(VarDef.class),
+        @JsonSubTypes.Type(WhileStmt.class),
+})
+public abstract class Node {
+
+    /**
+     * Node-type indicator for JSON form.
+     */
+    public final String kind;
+
+    /**
+     * Source position information: 0: line number of start, 1: column number
+     * of start, 2: line number of end, 3: column number of end.
+     */
+    private final int[] location = new int[4];
+
+    /**
+     * First error message "blamed" on this Node. When non-null, indicates
+     * that an error has been found in this Node.
+     */
+    @JsonInclude(JsonInclude.Include.NON_EMPTY)
+    private String errorMsg;
+
+    /**
+     * A Node corresponding to source text between LEFT and RIGHT.
+     */
+    public Node(Location left, Location right) {
+        if (left != null) {
+            location[0] = left.getLine();
+            location[1] = left.getColumn();
+        }
+        if (right != null) {
+            location[2] = right.getLine();
+            location[3] = right.getColumn();
+        }
+        this.kind = getClass().getSimpleName();
+        this.errorMsg = null;
+    }
+
+    /**
+     * Return my source location as
+     * { <first line>, <first column>, <last line>, <last column> }.
+     * Result should not be modified, and contents will change after
+     * setLocation().
+     */
+    public int[] getLocation() {
+        return location;
+    }
+
+    /**
+     * Copy LOCATION as getLocation().
+     */
+    public void setLocation(final int[] location) {
+        System.arraycopy(location, 0, this.location, 0, 4);
+    }
+
+    public String getErrorMsg() {
+        return errorMsg;
+    }
+
+    public void setErrorMsg(String msg) {
+        this.errorMsg = msg;
+    }
+
+    /**
+     * Return true iff I have been marked with an error message.
+     */
+    @JsonIgnore
+    public boolean hasError() {
+        return this.errorMsg != null;
+    }
+
+    /**
+     * Invoke ANALYZER on me as a node of static type T.  See the comment
+     * on NodeAnalyzer. Returns modified Node.
+     */
+    public abstract <T> T dispatch(NodeAnalyzer<T> analyzer);
+
+    /**
+     * Print out the AST in JSON format.
+     */
+    @Override
+    public String toString() {
+        try {
+            return toJSON();
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * Return a serialization of this node in JSON format.
+     */
+    public String toJSON() throws JsonProcessingException {
+        return mapper.writeValueAsString(this);
+    }
+
+    /**
+     * Mapper to-and-from serialized JSON.
+     */
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    static {
+        mapper.enable(SerializationFeature.INDENT_OUTPUT);
+        mapper.registerModule(new ParameterNamesModule());
+    }
+
+    /**
+     * Returns a T from JSON, a JSON-serialized T value with class
+     * CLAS.
+     */
+    public static <T> T fromJSON(String json, Class<T> clas)
+            throws IOException {
+        return mapper.readValue(json, clas);
+    }
+
+    /**
+     * Returns the result of converting JSON, a JSon-serialization of
+     * a Node value, into the value it serializes.
+     */
+    public static Node fromJSON(String json)
+            throws IOException {
+        return fromJSON(json, Node.class);
+    }
+
+    /**
+     * Returns the result of converting TREE to the value of type T
+     * that it represents, where CLAS reflects T.
+     */
+    public static <T> T fromJSON(JsonNode tree, Class<T> clas)
+            throws IOException {
+        return mapper.treeToValue(tree, clas);
+    }
+
+    /**
+     * Returns the translation of serialized value SRC into the
+     * corresponding JSON tree.
+     */
+    public static JsonNode readTree(String src) throws IOException {
+        return mapper.readTree(src);
+    }
+
+}