implement symboltable

src/main/java/typechecker/SymbolAlreadyDefinedException.java

@@ -0,0 +1,8 @@
+package typechecker;
+
+public class SymbolAlreadyDefinedException extends RuntimeException {
+
+    public SymbolAlreadyDefinedException(String message) {
+        super(message);
+    }
+}

src/main/java/typechecker/SymbolTable.java

@@ -0,0 +1,81 @@
+package typechecker;
+
+import parser.ast.AST;
+import parser.ast.Node;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static util.Logger.log;
+
+public class SymbolTable {
+
+    private final Map<String, String> symbolTable;
+    private final Map<String, String> methodTable;
+
+    public SymbolTable(Map<String, String> symbolTable) {
+        this.symbolTable = symbolTable;
+
+        final Map<String, String> methodTable = new HashMap<>();
+
+        methodTable.put("ADD", "INTEGER_TYPE");
+        methodTable.put("SUB", "INTEGER_TYPE");
+        methodTable.put("MUL", "INTEGER_TYPE");
+        methodTable.put("DIV", "INTEGER_TYPE");
+        methodTable.put("MOD", "INTEGER_TYPE");
+
+        methodTable.put("NOT", "BOOLEAN_TYPE");
+        methodTable.put("AND", "BOOLEAN_TYPE");
+        methodTable.put("OR", "BOOLEAN_TYPE");
+
+        methodTable.put("LESS", "BOOLEAN_TYPE");
+        methodTable.put("LESS_EQUAL", "BOOLEAN_TYPE");
+        methodTable.put("GREATER", "BOOLEAN_TYPE");
+        methodTable.put("GREATER_EQUAL", "BOOLEAN_TYPE");
+        methodTable.put("EQUAL", "BOOLEAN_TYPE");
+        methodTable.put("NOT_EQUAL", "BOOLEAN_TYPE");
+
+        this.methodTable = methodTable;
+    }
+
+    public static SymbolTable fromAST(AST tree) {
+        final Map<String, String> tableOut = new HashMap<>();
+
+        log("Creating SymbolTable");
+        scanTree(tree.getRoot(), tableOut);
+        log("-".repeat(100));
+
+        return new SymbolTable(tableOut);
+    }
+
+    private static void scanTree(Node root, Map<String, String> table) {
+        for (Node child : root.getChildren()) {
+            scanTree(child, table);
+        }
+
+        if ("DECLARATION".equals(root.getName())) {
+            Node left = root.getChildren().get(0);
+            Node right = root.getChildren().get(1);
+
+            log("Adding Entry " + right.getValue() + " -> " + left.getName());
+            String oldEntry = table.put(right.getValue(), left.getName());
+
+            if (oldEntry != null) {
+                System.out.println("Typfehler - Symbol bereits definiert: " + right.getValue());
+                throw new SymbolAlreadyDefinedException("Das Symbol " + right.getValue() + " wurde bereits deklariert.");
+            }
+        }
+    }
+
+    public String getSymbolType(String sym) {
+        return this.symbolTable.get(sym);
+    }
+
+    public String getMethodType(String meth) {
+        return this.methodTable.get(meth);
+    }
+
+    public int getSymbolCount() {
+        return this.symbolTable.size();
+    }
+}