Several types of types in programming languages

Types are an important part of any modern programming language, but we often forget that the concept of type we understand nowadays is not the same it was perceived in the sixties. Moreover, we conflate the concept of "type" in programming languages with the concept of the same name in mathematical logic, an identification that is only the result of the convergence of two different paths, which started apart with different aims. The paper will present several remarks (some historical, some of more conceptual character) on the subject, as a basis for a further investigation. The thesis we will argue is that there are three different characters at play in programming languages, all of them now called types: the technical concept used in language design to guide implementation; the general abstraction mechanism used as a modelling tool; the classifying tool inherited from mathematical logic. We will suggest three possible dates ad quem for their presence in the programming language literature, suggesting that the emergence of the concept of type in computer science is relatively independent from the logical tradition, until the Curry-Howard isomorphism will make an explicit bridge between them.Comment: History and Philosophy of Computing, HAPOC 2015. To appear in LNC

Early Nordic compilers and autocodes

Abstract. The early development of compilers for high-level program-ming languages, and of so-called autocoding systems, is well documented at the international level but not as regards the Nordic countries. The goal of this paper is to provide a survey of compiler and autocode development in the Nordic countries in the early years, roughly 1953 to 1965, and to relate it to international developments. We also touch on some of the historical societal context

Fundamentos da POO (programação orientada por objectos) : programar computadores com objectos

Lusíada. Economia & empresa. - ISSN 1645-6750. - S. 2, n. 19 (2015). - p. 199-220A Programação Orientada por Objectos, apesar de ter surgido na década de 60, só começou a ser mais reconhecida e utilizada a partir dos anos 80, tendo o conceito de Objecto ultrapassado a programação, passando pelas bases de dados e chegando até aos modelos de concepção de aplicações informáticas. Ganhou reconhecimento na comunidade científica e é hoje largamente utilizada na indústria de desenvolvimento de software. O presente artigo pretende explicar este paradigma de programação, de uma forma simples e clara, abordando as suas origens e evolução, expondo as suas principais componentes e características que permitem compreender como programar computadores com Objectos

The role of concurrency in an evolutionary view of programming abstractions

In this paper we examine how concurrency has been embodied in mainstream programming languages. In particular, we rely on the evolutionary talking borrowed from biology to discuss major historical landmarks and crucial concepts that shaped the development of programming languages. We examine the general development process, occasionally deepening into some language, trying to uncover evolutionary lineages related to specific programming traits. We mainly focus on concurrency, discussing the different abstraction levels involved in present-day concurrent programming and emphasizing the fact that they correspond to different levels of explanation. We then comment on the role of theoretical research on the quest for suitable programming abstractions, recalling the importance of changing the working framework and the way of looking every so often. This paper is not meant to be a survey of modern mainstream programming languages: it would be very incomplete in that sense. It aims instead at pointing out a number of remarks and connect them under an evolutionary perspective, in order to grasp a unifying, but not simplistic, view of the programming languages development process

The Nordic Ingredient. European Nationalisms and Norwegian Music since 1905

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Nature and spirit: Arne Korsmo and Frank Lloyd Wright's organicism

O arquitecto norueguês Arne Korsmo (1900-1968) é frequentemente associado aos princípios orgânicos defendidos pelo arquitecto americano Frank Lloyd Wright (1867-1959) em consonância com a sua obra no período pós-Segunda Guerra Mundial. O exemplo mais emblemático é Villa Planetveien 12 (1955) projetada por Korsmo e seus colaboradores, em Oslo. Antes da Segunda Guerra Mundial, Korsmo era conhecido como "Le Corbusier da Noruega". No entanto, ao compararmos o percurso de Wright, iniciado na infância, durante a construção de seus princípios orgânicos; com o percurso intelectual e arquitectónico percorrido por Korsmo, podemos identificar paralelos entre esses dois arquitetos. Korsmo teria se tornado orgânico em termos "Wrightianos" mesmo sem a influência direta de Wright? Korsmo já era orgânico antes da Segunda Guerra Mundial? Nossa tese é que o "Korsmo orgânico" existia antes da Villa Planetveien 12. Argumentamos que o caminho de Frank Lloyd Wright rumo ao seus princípios orgânicos abre uma porta para entendermos tanto o próprio organicismo de Korsmo quanto sua atração pelo Funcionalismo. Esta tese apresenta três pressupostos que interligam eventos cruciais na vida de Korsmo e Wright; fundamentada nas ideias transcendentais de uma das maiores referências de Frank Lloyd Wright, o filósofo, ensaísta e poeta norte-americano Ralph Waldo Emerson (1803-1882).The Norwegian architect Arne Korsmo (1900-1968) is often associated with the organic principles defended by the American architect Frank Lloyd Wright (1867-1959) in keeping with his work in the post-World War II (WWII) period. The most emblematic example comes with Villa Planetveien 12 (1955) designed by Korsmo and his collaborators, in Oslo. Prior to WWII, Korsmo had been known as "Norway's Le Corbusier." Nevertheless, by comparing Wright's journey towards the construction of his organic principles from an early age with Korsmo's own path, we are able to identify further parallels between these two architects. Would Korsmo have become organic in "Wrightian" terms even without the direct influence of Wright? Was Korsmo already organic prior to WWII? Our thesis is that the organic Korsmo existed prior to Villa Planetveien 12. We also argue that Frank Lloyd Wright's path towards his organic principles opens a door to understanding both Korsmo's own organicism and his attraction to Functionalism. This thesis presents three assumptions that interconnect crucial events in Korsmo and Wright's life; grounded by the transcendental ideas of one of Frank Lloyd Wright's major reference, the American philosopher, essayist and poet Ralph Waldo Emerson (1803-1882)