Today we’ll learn about type inference from scratch
- Git
- IntelliJ
From Wikipedia:
Type inference refers to the automatic detection of the type of an expression in a programming language.
- Getting to know our Programming Language & Example programs
- Representing programs as data. Our Abstract Syntax in Kotlin
- Building a type inferencer alternating between Mob & Pair Programming
- Clone the repo at: https://github.com/kritzcreek/infer_workshop
- Open the Project in IntelliJ (it should be recognized as a Gradle project)
- If everything worked out running the
Examplesrun task should execute our example programs.
The pre-configured test configurations in IntelliJ should be made
green in the following order. To do so you should only need to edit
types/TypeChecker.kt. (You’re free to look at any other file and
read all the code, just don’t be lead astray). All relevant data types
can be found in syntax/AST.kt. Please don’t hesitate to use
breakpoints and the debugger.
- Literal & Var
- Let
- Lambda
- Substitution
- Unify
- Application
- If
- (Bonus) Recursive Let
- Algorithm W Step by Step (Martin Grabmueller) http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.65.7733&rep=rep1&type=pdf
- Types and Programming Languages - Benjamin C. Pierce
- A stateless implementation in Haskell: https://github.com/kritzcreek/fby19
- The original paper: Principal type-schemes for functional programs - Damas & Milner https://web.cs.wpi.edu/~cs4536/c12/milner-damas_principal_types.pdf