How Programming Languages Affect Design Patterns

Abstract

This thesis is an empirical study of the affects that Language Features, provided by Programming Languages on Design Pattern implementa- tions. The set of Design Patterns is mostly based on the ones described by first book to document Design Patterns, namely the Gang of Four book [31]. It examines comparatively two Programming Languages, Java and Python. In terms of comparing Language Features and Design Pattern implementations in across the two Programming Languages. The examin- ation is based on the Programming Languages’ documentation as well as the literature available with regards to Design Pattern implementations in these Programming Languages. Such cross language study, has not been conducted before and thus it is an approach to the topic of Design Patterns from a novel perspective. The thesis proposes a classification scheme with regards to Language Features in relation to Design Pattern. In addition to that it proposes a categorization scheme of Language Features, that im- plement Design Patterns in Programming Languages. It also assesses the dependence of Design Patterns on specific Language Features. This thesis also examines some of the observed effects of Design Patterns on Programming Languages, by comparative examination of two languages. It also catalogs related Language Features’ development over time. Leading to the definition of the relationship between Design Patterns and Programming Languages as bidirectional. And the theory, explaining the consequences of changes to either Design Patterns or Programming Languages.