fix assignment and adding IfStatement

src/AST/AssignmentExpression.cpp

@@ -1,7 +1,7 @@
 #include "AST/AssignmentExpression.h"
 #include "AST/ASTVisitor.h"
 
-AssignmentExpression::AssignmentExpression(std::string id, Expression *expr)
+AssignmentExpression::AssignmentExpression(std::string id, Expression *expr) : id_(id),expr_(expr)
 {
     //
 }

src/AST/IfStatement.cpp

@@ -0,0 +1,23 @@
+#include "AST/IfStatement.h"
+#include "AST/ASTVisitor.h"
+
+IfStatement::IfStatement(Expression *cond, Statement *stmt) : cond_(cond),stmt_(stmt)
+{
+    //
+}
+
+IfStatement::~IfStatement(){
+    //
+}
+
+void IfStatement::accept(ASTVisitor *visitor) {
+    visitor->visit(this);
+}
+
+Expression* IfStatement::getCond() {
+    return cond_;
+}
+
+Statement* IfStatement::getStmt() {
+    return stmt_;
+}