Building a Compiler with C#

Your IDE's refactoring tools are powered by a compiler. We'll build a simple one in C# to see exactly how it's done.

#1about 4 minutes

Understanding the Roslyn compiler platform for C#

Roslyn is more than a black-box compiler, providing rich language service APIs that power IDE features like refactoring and code analysis.

#2about 2 minutes

Exploring C# code with Roslyn and LINQPad

Use a tool like LINQPad to see how Roslyn transforms C# source code into intermediate language (IL) and visualizes it as a syntax tree.

#3about 4 minutes

The motivation for building a custom language

A custom, high-performance language was needed to power a game that dynamically generates worlds from user-defined mathematical formulas.

#4about 3 minutes

Defining a language with a formal grammar

Creating a new language starts with a formal specification or grammar that defines its syntax using symbols and rules.

#5about 3 minutes

How compilers transform source code into executables

Compilers translate source code into a machine-readable format, either directly into object files or into platform-independent bytecode for a virtual machine.

#6about 5 minutes

The core stages of parsing source code

The parsing process involves multiple stages, including stream processing, tokenization, abstract syntax tree (AST) generation, and semantic analysis.

#7about 6 minutes

Structuring code with an Abstract Syntax Tree

An Abstract Syntax Tree (AST) represents code structure using nodes for statements and expressions, respecting operator precedence.

#8about 3 minutes

Traversing the AST using the Visitor Pattern

The Visitor design pattern provides a robust and type-safe way to traverse an Abstract Syntax Tree for analysis or code generation.

#9about 3 minutes

A live demo of a custom language REPL

A simple Read-Eval-Print Loop (REPL) demonstrates the custom language's features, including function definitions, currying, and AST inspection.

#10about 2 minutes

Implementing operator precedence with Pratt parsing

Pratt parsing is a technique that uses recursive function calls to elegantly handle operator precedence climbing in a compiler.

#11about 4 minutes

Understanding virtual machines and intermediate language

Process virtual machines execute platform-independent bytecode, or intermediate language (IL), which provides a linear instruction set derived from the AST.