$35
POSD-Assignment 4 Solved
The folders `src/` and `test/` in this repo contain the template code of the
assignment, which is just the skeleton.
You need to finish the implementation by yourself.
For this assignment, you are asked to implement `Visitor` pattern.
Please add to the skeleton code so that it meets the specifications below.
- The specs of `Shape`, `Circle`, `Rectangle`, `Triangle` and
`TwoDimensionalVector` is extended from the assignment 3.
- abstract class `Shape`, which has a pure virtual function `accept` and `info`.
- function `accept` takes a visitor as parameter and visit the shape.
- function `info` returns a string that describes the shape.
- `Circle` returns "Circle (${radius})".
- `Rectangle` returns "Rectangle (${length}, ${width})".
- `Triangle` returns "Triangle (${vec1.info()}, ${vec2.info()})".
- `CompoundShape` returns "CompoundShape".
- class `CompoundShape`, which deletes first matching Shape object in function
`deleteShape`, and it will traverse all its descendants.
---
- The specs of `Iterator` is extended from the assignment 3, you should keep all
iterator functionality work in this assignment.
---
- Abstract class `ShapeVisitor` defines four pure virtual functions `visitCircle`,
`visitRectangle`, `visitTriangle` and `visitCompoundShape`.
- Class `ShapeInfoVisitor` is derived from `ShapeVisitor`, implements all pure
functions defined in `ShapeVisitor`.
- Class `ShapeInfoVisitor` generates shape info in following rule:
- when visit `Circle`, visitor generates "Circle (${radius})\n".
- when visit `Rectangle`, visitor generates "Rectangle (${length}, ${width})\n".
- when visit `Triangle`, visitor generates "Triangle (${vec1.info()}, ${vec2.info()})
\n".
- when visit `CompoundShape`, visitor wraps children's info with `CompoundShape{\n...}\n`
and adds indent by their depth in the compound tree.
---
- TA will only check `ShapeVisitor`, `accept()`, `info()`, `deleteShape()`, but you still needs to keep all legacy system work.
#### Example:
``` c++
CompoundShape* cs1 = new CompoundShape();
cs1->addShape(new Circle(1.1));
cs1->addShape(new Rectangle(3.14 ,4));
CompoundShape* cs2 = new CompoundShape();
cs2->addShape(new Circle(12.34567))
cs2->addShape(cs1);
ShapeInfoVisitor visitor;
cs2.accept(&visitor);
```
result of `visitor.getResult()`(don't print '\n', it just remind you there has a \n)
```
CompoundShape{\n
Circle (12.35)\n
CompoundShape{\n
Circle (1.10)\n
Rectangle (3.14 4.00)\n
}\n
}\n
```
#### Notes:
- If your code fails to compile on the Jenkins server, you'll get **NO POINT**
for the assignment.
- Your program should be able to handle unexpected input data, that is, you
should do error handling if necessary.
- You should make your unit test fail if the program that should throw an
exception runs without throwing one.
- When writing unit tests, you should take as many situations as possible into
consideration.
- Discussion is encouraged but the pushed code must be your own.
- Any submission after deadline will not be graded.
- You don't need to delete the tests written before.
- Remember to **RELEASE THE SPACE** you allocate after using it.
### File Structure
```bash
.
├── makefile
├── src
│ ├── circle.h
│ ├── compound_shape.h
│ ├── iterator
│ │ ├── compound_iterator.h
│ │ ├── iterator.h
│ │ └── null_iterator.h
│ ├── rectangle.h
│ ├── shape.h
│ ├── triangle.h
│ ├── two_dimensional_vector.h
│ └── visitor
│ ├── shape_info_visitor.h
│ └── shape_visitor.h
└── test
├── iterator
│ ├── ut_compound_iterator.h
│ └── ut_null_iterator.h
├── ut_circle.h
├── ut_compound_shape.h
├── ut_main.cpp
├── ut_rectangle.h
├── ut_triangle.h
├── ut_two_dimensional_vector.h
└── visitor
└── ut_shape_info_visitor.h
```
## References
- [C++.com](http://www.cplusplus.com/reference/)
## Course Link
Course Link: https://ssl-gitlab.csie.ntut.edu.tw/yccheng/posd2021f
## Environment Setting
Tutorial: https://ssl-gitlab.csie.ntut.edu.tw/course/environment_setting.git
