commit 6661dca50043e1a52adb48db45cb0c6ef7c6afa8
parent 2f9f2455aaeb0ab7acd1717676e078196d135e76
Author: Mohammad-Reza Nabipoor <m.nabipoor@yahoo.com>
Date: Thu, 17 Sep 2020 06:34:04 +0430
README.md: Add description for kal::ASTNode
Diffstat:
| M | README.md | | | 35 | +++++++++++++++++++++++++++++++++++ |
1 file changed, 35 insertions(+), 0 deletions(-)
diff --git a/README.md b/README.md
@@ -178,3 +178,38 @@ Token{
/*str*/ "",
}
```
+
+## Chapter 2: Kaleidoscope: Implementing a Parser and AST
+
+- **Implementation** `kaleidoscope_ast.hpp`, `kaleidoscope_ast.cpp`
+- **Test** `tests/kaleidoscope_ast.test.cpp`
+
+Each node of AST (Abstract Syntax Tree) can be saved in `ASTNode` class. It's a
+polymorphic type that accepts an instance of type `T` that satisfies the
+following requirements:
+
+- `T` is a
+ [SemiRegular type](https://en.cppreference.com/w/cpp/concepts/semiregular)
+- The following functions are defined:
+ - `std::string to_string(const T&);`
+ - `kal::NodeType node_type(cons T&);`
+
+`kal::NodeType` is an `enum class`:
+
+```c++
+enum class NodeType
+{
+ None = -1,
+ Number,
+ Variable,
+ BinaryOp,
+ Call,
+ Prototype,
+ Function,
+};
+```
+
+For more information about implementation details of this polymorphic type and
+the benefits of this design, you can watch
+[this great talk by Sean Parent](https://youtu.be/QGcVXgEVMJg).
+If you're impatient you can go directly to time `49:13`.
