Lambda? You Keep Using that Letter
summary
Lambdas originate with Alonzo Church in 1936 and rest on three laws: variables abstraction application; they can encode numbers (Church numerals) so zero, one, two become functions and composing those recreates arithmetic (example: encoding square yields 7 squared → 49). Languages differ: Algol 68 and Scheme treat procedures as first‑class, closures implement private state and can model objects (stack example), Java adds lambdas in 2014 but Java lambdas are polyexpressions not full typed functions and require conversion to functional interfaces, Excel recently gains true lambdas with recursion.
AI-written summary · about
chapters (12)
- 0:00Lambda confusion
- 3:24Lambdas beyond FP
- 10:01JavaScript lambda evolution
- 13:14Lambdas in ALGOL
- 16:43Closures and lambdas
- 20:18Lambdas as foundational to object orientation
- 23:23Lambda notation history
- 26:55Java’s lambda flaws
- 29:01Excel’s lambda
- 30:48Church numerals
- 35:18Lambda encodings in practice
- 37:25Conclusion
related talks
49mLambda? You Keep Using that Letter
01h 01mLambda? You Keep Using that Letter
53mExplaining Lambda Calculus through Plain JavaScript
34mAn introduction to Lambda Calculus
30mLambda Calculus: The Origins of Functional Programming
59mLambdas from First Principles: A Whirlwind Tour of C++""
36mAbstract Machines for Good
06mOffers a View Into Lambda Development