Made toString functions and overloaded the stream operator

src/operations/node.cpp

@@ -21,47 +21,53 @@ void check_num_nodes(Node* node, uint num_children, std::string error) {
   }
 }
 
-void print_tree(Node* node, uint tabs) {
+std::ostream & operator << (std::ostream &out, const Node* n) { 
+  out << n->toString();
+  return out;
+}
+
+std::string Node::toString() const {
+  return tree_string(this, 0);
+}
+
+std::string tree_string(const Node* node, uint tabs) {
+  std::string result = "";
   uint i;
   /* base case */
   if(!node) {
-    std::cerr << "NO TREE STRUCTURE" << std::endl;
+    result += "NO TREE STRUCTURE\n";
-    return;
+    return result;
   }
 
   /* print leading tabs */
   for(i = 0; i < tabs; i++) {
-    std::cout << "    ";
+    result += "    ";
   }
 
   switch(node->type) {
-    case IDENTIFIER: std::cout << "IDENTIFIER: " << node->id << std::endl; break;
+    case IDENTIFIER: result += "IDENTIFIER: " + node->id + "\n"; break;
-    case PLUS: std::cout << "PLUS:" << std::endl; break;
+    case PLUS: result += "PLUS:\n"; break;
-    case MINUS: std::cout << "MINUS:" << std::endl; break;
+    case MINUS: result += "MINUS:\n"; break;
-    case DIVIDE: std::cout << "DIVIDE:" << std::endl; break;
+    case DIVIDE: result += "DIVIDE:\n"; break;
-    case TIMES: std::cout << "TIMES:" << std::endl; break;
+    case TIMES: result += "TIMES:\n"; break;
-    case LESS: std::cout << "LESS THAN:" << std::endl; break;
+    case LESS: result += "LESS THAN:\n"; break;
-    case GREATER: std::cout << "GREATER:" << std::endl; break;
+    case GREATER: result += "GREATER:\n"; break;
-    case LESSEQ: std::cout << "LESS EQUAL:" << std::endl; break;
+    case LESSEQ: result += "LESS EQUAL:\n"; break;
-    case GREATEREQ: std::cout << "GREATER EQUAL:" << std::endl; break;
+    case GREATEREQ: result += "GREATER EQUAL:\n"; break;
-    case EQUALS: std::cout << "EQUAL:" << std::endl; break;
+    case EQUALS: result += "EQUAL:\n"; break;
-    case NEQUALS: std::cout << "NOT EQUAL:" << std::endl; break;
+    case NEQUALS: result += "NOT EQUAL:\n"; break;
-    case AND: std::cout << "AND:" << std::endl; break;
+    case AND: result += "AND:\n"; break;
-    case OR: std::cout << "OR:" << std::endl; break;
+    case OR: result += "OR:\n"; break;
-    case NOT: std::cout << "NOT:" << std::endl; break;
+    case NOT: result += "NOT:\n"; break;
-    case ASSIGN: std::cout << "ASSIGN:" << std::endl; break;
+    case ASSIGN: result += "ASSIGN:\n"; break;
-    case IF: std::cout << "IF:" << std::endl; break;
+    case IF: result += "IF:\n"; break;
-    case WHILE: std::cout << "WHILE:" << std::endl; break;
+    case WHILE: result += "WHILE:\n"; break;
-    case PRINT: std::cout << "PRINT:" << std::endl; break;
+    case PRINT: result += "PRINT:\n"; break;
-    case INPUT: std::cout << "INPUT:" << std::endl; break;
+    case INPUT: result += "INPUT:\n"; break;
-    case LAMBDATAG: std::cout << "LAMBDA:" << std::endl; break;
+    case LAMBDATAG: result += "LAMBDA:\n"; break;
-    case CALLFUNC: std::cout << "FUNCCALL:" << std::endl; break;
+    case CALLFUNC: result += "FUNCCALL:\n"; break;
-    case STATEMENT: std::cout << "STATEMENT:" << std::endl; break;
+    case STATEMENT: result += "STATEMENT:\n"; break;
-    case VALUE: 
+    case VALUE: result += "VALUE: " + node->value->toString() + "\n"; break;
-      std::cout << "VALUE: ";
-      print_value(node->value);
-      std::cout << std::endl;
-     break;
     default:
       std::cerr << "Error, " << node->type << " is not a valid node type." << std::endl;
       exit(1);
@@ -69,10 +75,11 @@ void print_tree(Node* node, uint tabs) {
 
   /* print all children nodes underneath */
   for(i = 0; i < node->num_children; i++) {
-    print_tree(node->children[i], tabs + 1);
+    result += tree_string(node->children[i], tabs + 1);
   }
-}
 
+  return result;
+}
 
 Value* eval_expression(Node* node, Environment* env) {
   /* base case */
@@ -195,7 +202,6 @@ Value* eval_expression(Node* node, Environment* env) {
       break;
     //----------
     case INPUT: // We're only going to support reading in doubles
-      // Look into deleting possible values...?
       scanf("%lf", &temp);
       return make_double(temp);
       break;
@@ -271,8 +277,7 @@ void eval_statement(Node* node, Environment* env) {
     case PRINT:
       check_num_nodes(node, 1, "can only print out one expression at a time.");
       tempVal = eval_expression(node->children[0], env);
-      print_value(tempVal);
+      std::cout << tempVal << std::endl;
-      printf("\n");
       break;
     //------------
     case STATEMENT: // Can have a maximum of two children statement nodes

src/operations/node.hpp

@@ -25,6 +25,10 @@ class Node {
   uint num_children;
   std::array<Node*, MAX_CHILDREN> children;
 
+  friend std::ostream & operator << (std::ostream &out, const Node* n);
+
+  std::string toString(void) const;
+
   Node(int t, Value* v, std::string s) {
     type = t;
     value = v;
@@ -45,7 +49,7 @@ class Node {
 // Abstract Syntax Tree Functions
 // struct Node* make_node(int type, struct Value* value, std::string id);
 void attach_node(Node* parent, Node* child);
-void print_tree(Node* node, int tabs);
+std::string tree_string(const Node* node, uint tabs);
 
 // Interpreting AST
 void eval_statement(Node* node, Environment* env);

src/variables/value.cpp

@@ -31,26 +31,21 @@ void delete_value(Value* val) {
   free(val);
 }
 
-long get_long(Value* val) {
+long get_long(const Value* val) {
-  // return val->value.num;
   return std::get<long>(val->val);
 }
-double get_double(Value* val) {
+double get_double(const Value* val) {
-  // return val->value.dec;
   return std::get<double>(val->val);
 }
-Node* get_expression(Value* val) {
+Node* get_expression(const Value* val) {
-  // return val->value.expr;
   return std::get<Node*>(val->val);
 }
-std::string get_string(Value* val) {
+std::string get_string(const Value* val) {
-  // return val->value.str;
   return std::get<std::string>(val->val);
 }
 
 void set_long(Value* val, long num) {
   val->type = LONG;
-  // val->value.num = num;
   val->val = num;
 }
 void set_double(Value* val, double dec) {
@@ -60,29 +55,36 @@ void set_double(Value* val, double dec) {
 }
 void set_expression(Value* val, Node* expr) {
   val->type = LAMBDA;
-  // val->value.expr = expr;
   val->val = expr;
 }
 void set_sring(Value* val, std::string str) {
   val->type = STRING;
-  // val->value.str = str;
   val->val = str;
 }
 
-void print_value(Value* val) {
+std::string Value::toString() const {
-  if (val->type == BOOLEAN) {
+  std::string result = "";
-    if (get_long(val)) {
+  if (this->type == BOOLEAN) {
-      std::cout << "true";
+    if (get_long(this)) {
+      result += "true";
     } else {
-      std::cout << "false";
+      result += "false";
     }
-  } else if (val->type == LONG) {
+  } else if (this->type == LONG) {
-    std::cout << get_long(val);
+    result += get_long(this);
-  } else if (val->type == STRING) {
+  } else if (this->type == STRING) {
-    std::cout << get_string(val);
+    result += get_string(this);
-  } else if (val->type == DOUBLE) {
+  } else if (this->type == DOUBLE) {
-    std::cout << get_double(val);
+    result += get_double(this);
   } else { // Assume lambda expression
-    std::cout << "<LambdaExpression>";
+    result += "<LambdaExpression>";
   }
+
+  return result; 
 }
+
+std::ostream & operator << (std::ostream &out, const Value* val) { 
+  out << val->toString();
+  return out; 
+} 
+  

src/variables/value.hpp

@@ -15,6 +15,11 @@ class Value {
     enum TypeTag type;
     std::variant<long, double, Node*, std::string> val;
 
+    // << Overload
+    friend std::ostream & operator << (std::ostream &out, const Value* val);
+    std::string toString() const;
+
+    // Constructor
     Value(TypeTag t, long n, double d, Node* e, std::string s) {
       /* set properties */
       type = t;
@@ -30,35 +35,34 @@ class Value {
       }
     }
 
+  // Destructor
   ~Value() {  
     std::cout << "VALUE DESTROYED" << std::endl;
   }
 };
 
 // Constructors
-struct Value* make_long(long num);
+Value* make_long(long num);
-struct Value* make_double(double dec);
+Value* make_double(double dec);
-struct Value* make_true();
+Value* make_true();
-struct Value* make_false();
+Value* make_false();
-struct Value* make_boolean(int x);
+Value* make_boolean(int x);
-struct Value* make_expression(struct Node* expr);
+Value* make_expression(Node* expr);
-struct Value* make_string(std::string str);
+Value* make_string(std::string str);
 
 // Destructor
-void delete_value(struct Value* val);
+void delete_value(Value* val);
 
 // Getters
-long get_long(struct Value* val);
+long get_long(const Value* val);
-double get_double(struct Value* val);
+double get_double(const Value* val);
-struct Node* get_expression(struct Value* val);
+Node* get_expression(const Value* val);
-std::string get_string(struct Value* val);
+std::string get_string(const Value* val);
 
 // Setters
-void set_long(struct Value* val, long num);
+void set_long(Value* val, long num);
-void set_double(struct Value* val, double dec);
+void set_double(Value* val, double dec);
-void set_expression(struct Value* val, struct Node* node);
+void set_expression(Value* val, Node* node);
-void set_string(struct Value* val, std::string str);
+void set_string(Value* val, std::string str);
-
-void print_value(struct Value* val);
 
 #endif