#### Spotlight on Philip Wadler

**Language:** Agnostic

**When:** Saturday, October 1st - 19:30 - 20:30

##### Category Theory for the Working Hacker

The talk will explain why category theory is of interest for developers. The principle of Propositions as Types describes a correspondence between propositions and proofs in logic, on the one hand, and types and programs in computing, on the other. Category theory constitutes a third leg of this correspondence. Assuming only enough familiarity with functional programming that you know why ‘Lambda World’ has that name, the talk will explain how to model products (logical and), sums (logical or), and functions (logical implication), and why you already learned the most important stuff in high school.

##### About Philip:

Philip Wadler (born April 8, 1956) is an American computer scientist known for his contributions to programming language design and type theory. In particular, he has contributed to the theory behind functional programming[8] and the use of monads in functional programming, the design of the purely functional language Haskell,[9] and the XQuery declarative query language. In 1984, he created the Orwell programming language. Wadler was involved in adding generic types to Java 5.0.[10] He is also author of the paper ‘Theorems for free!’ that gave rise to much research on functional language optimization (see also Parametricity).

Cool Fact: In 2005, Wadler became a Fellow of the Royal Society of Edinburgh and in 2007 was inducted as a Fellow of the Association for Computing Machinery. Find out more at here: Philip Wadler’s home page

#### About Lambda World:

Lambda World takes place September 30th - October 1st, in Cadiz, Spain and is hosted by 47 Degrees in conjunction with the Scala and Java communities of Spain. The event is located at the Palacio de Congresos, an old tobacco factory near the beach. You can find more details at Lambda.world.