Hackle's blog
between the abstractions we want and the abstractions we get.

Strong Code - workshop & book

Singleton types and their use in C#, Kotlin and others

404: Not Found

Last updated on 12-Oct-2025

See also

Type safe GADT in Kotlin - who needs Haskell?
Dependent? Extensible? The curious case of union type in Kotlin
Using, with are lame. Rust wins resource management
Accidentally coupled! The worst coupling by loose coupling
Scan is Zip? Laziness and recursion strike again!
Your Generics may be different than mine
Applicative and Monad: confusion in effect
Constructive code - an aimless exploration
DOWN, ISP & IoC: dependency rule #1, and how to stop lying code
Functional Programming: Choose Haskell / F# Because Syntax Matters
A Square IS A Rectangle - If Designed Correctly
State Monad: a bit of currying goes a long way
extends in TypeScript: inheritance, upper bounds, conditional, distributive and variance
Convenience Driven Development: A story of two exceptions
Convenience Driven Development: the Grandfather Paradox and Equality
Composition over aggregation, not just inheritance
Libraries should not provide interfaces for Dependency Injection - and stop asking
Parsing with Parsec: or, optional, retry and back-tracking
Stringly-typed: it's not that simple!
One recursion for all! Catamorphism step by step
Postel's law is simple - to fulfil the potential of your code
Unions are Untagged, and should be Discriminated in TypeScript: undecidable, collapse, and anti-patterns
PATCH-friendly types: null confusion, undefined envy and maybe maybe
void vs unit: Respect the Honesty of void
Reflections, Broken Promises and Fake generics: the anti-pattern
Generics: are you keeping it generic?
Abilities by birth? Separation of types, data and behaviour
Type Witness: not yet TypeScript, sure thing Haskell
On the geometric beauty of programming
Not assignable? A must-cast situation! TypeScript, wise 'as any'
Functions and classes don't mix - not always
Readability misses the point - look instead at vocabulary
Is TYPEScript Turing complete? Not sure. Game of life? Why not!
Golang error handling: yes to values, no to exceptions, a win for the future
TypeScript Fireworks: Union, Intersection and Variance
TypeScript: Convert Union to Tuple/Array, Yes but How?
Types or Operations: keep it closed, or keep it open
Ad-hoc polymorphism: Same input, different output, still pure
Architecture? You mean spreadsheets?
A taste of Rust
Your tests may belong elsewhere
Dependency hell? Not if we use functions! For library authors
Linq is Lazier, not by too much, just within Range
The TypeScript Handbook, Optional Parameters and Postel's Law
On accidental code deletion as reason for unit testing
A truly strongly-typed printf in TypeScript
Literal type preservation with TypeScript
Dependent Types in TypeScript, Seriously
Also on Comonad and Conway's game of life
Self-referenced JSON?
Plain and simple state management
The 'Constants' file is an anti-pattern, so is the 'Interface' folder. Placement by functionality, not technical concerns
Setting CAP loose in real life
Tuck-away and take-one, whatever it takes to look declarative
The Diamond, squashed and recovered
Dependent types in TypeScript?
Reducer to reduce, with lens in OO flavour
Nesting and positions in covariance and contravariance,
T.D.D. is most practical data-driven with pure functions
Covariance and contravariance
the magic Const, Identity and tuple
Out-of-context string template is an anti-pattern
Types, names, and type superstition
Types and tests: JavaScript 10, Idris 0
2-layer architecture
Don't null check, just continue!
Make unit testing a breeze by segregating complexity
Inject functions, not interfaces
foldl in terms of foldr
Serialize like javascript - the idea
Serialize like javascript - MergeJSON in Idris!
My take on (unit) testing
callCC in Haskell, and my ultimate Monad
Coding an alternative Vect.index, Type-Driven Development in Idris
Fin
Lens (really record viewer / updater) in TypeScript
LINQ, infinity, laziness and oh my!

About me and this blog, or get in touch