JEDI: An interactive interpreter for JAVA

JAVA is a general purpose concurrent class-based object-oriented programming language. This work presents an interactive program that interprets JAVA source programs directly. The cornerstone of its execution model is an execution graph, in which each node is constituted by three functions: a state transformer, a continuation and an exception handler.Eje: Sistemas operativosRed de Universidades con Carreras en Informática (RedUNCI

A view on abstract and extensibles types

This paper presents a type declaration construct which provides either a type synonym, a datatype, an abstract type with views, a subtype of an existing type, or a module (collection of declarations), in the style of modern functional programming languages ahich provide support for parametric polymorphism

Atividade biológica de extratos acetato de etila, etanólico e aquoso de timbó (Lonchocarpus floribundus) sobre carrapato bovino

Os extratos acetato de etila, etanólico e aquoso de raízes de Lonchocarpus floribundus foram utilizados, a fim de avaliar a atividade biológica sobre carrapato bovino. Carrapatos adultos foram coletados em bovinos infestados artificialmente, separados em grupos de dez indivíduos, pesados e imersos, separadamente, nos extratos de raízes de L. Floribundus, nas concentrações de 5, 25, 50, 75 e 100 mg mL-1. Para a avaliação em larvas, foram utilizados indivíduos de 14 a 21 dias, os quais foram imersos nos extratos nas concentrações de 1, 5, 10, 15 e 20 mg mL-1. Após o tratamento, cada grupo foi colocado em placa de Petri e incubado a 27 ± 1 ºC e umidade relativa de 80 ± 5%. Os extratos avaliados não foram eficazes para induzir, acima de 50%, a mortalidade de fêmeas ingurgitadas. Os extratos acetato de etila e etanólico induziram 100% de mortalidade de larvas. Entretanto, quanto aos valores de concentração letal mediana (CL50), o extrato etanólico (CL50 = 2,1 mg mL-1) foi mais tóxico que o extrato acetato de etila (CL50 = 4,1 mg mL-1). O extrato etanólico estimou concentração inibitória mediana (CI50) de 3,0 mg mL-1 e foi mais tóxico que os demais extratos quanto a este parâmetro de avaliação. Entre os três extratos avaliados, os extratos acetato de etila e etanólico apresentaram os melhores resultados quanto ao controle de reprodução de R. (B.) microplus, atingindo 100% na concentração de 5 mg mL-1. Os extratos de raízes de L. Floribundus apresentaram atividade biológica sobre carrapato bovino

Typing polymorphic recursion

This paper discusses some advantages of supporting polymorphic recursión in programming languages and describes a decidable type inference algorithm for typing polymorphic and possibly mutually recursive definitions, using Haskell to provide an executable high level specification of the algorithm.Eje: Informática teóricaRed de Universidades con Carreras en Informática (RedUNCI

Constraint-set satisfiability for overloading

This article discusses the problem of constraint-set satisfiability (CS-SAT) — that is, the problem of determining whether a given constraint-set is satisfiable in a given typing context — in the context of systems with support for overloading and parametric polymorphism. The paper reviews previous works on constraint-set satisfiability, showing that overloading policies used in order to guarantee decidability of CS-SAT have been generally too restrictive. An algorithm is proposed that does not impose a severe restriction on possible overloadings and decides CS-SAT in an expectedly vast majority of cases of practical interest. In cases for which satisfiability cannot be decided, a configurable limit on the number of iterations is used in order to guarantee termination. 1

A view on abstract and extensible types.

This paper presents a type declaration construct which provides either a type synonym, a datatype, an abstract type with views, a subtype of an existing type, or a module (collection of declarations), in the style of modern functional programming languages ahich provide support for parametric polymorphism

Towards higher-order types.

This article explores the use of types constrained by the definition of functions of given types. This notion supports both overloading and a form of subtyping, and is related to Haskell type classes and System O. We study an extension of the Damas-Milner system, in which overloaded functions can be defined. The inference system presented uses a context-independent overloading policy, specified by means of a predicate used in a single inference rule. The treatment of overloading is less restrictive than in similar systems. Type annotations are not required, but can be used to simplify inferred types. The work motivates the use of constrained types as parameters of other, higher-order types