A Survey of the Forms of Java Reference Names

Abstract

Abstract-The readability of identifiers is a major factor of program comprehension and an aim of naming convention guidelines. Due to their semantic content, identifiers are also used in feature and bug location, among other software maintenance tasks. Looking at how names are used in practice may lead to insights on potential problems for comprehension and for programming support tools that process identifiers.Class and method names are already well represented in the literature. This paper presents an investigation of Java field, formal argument and local variable names, which we collectively call reference names. These names cannot be ignored because they constitute over half the unique names and almost 70% of the name declarations in the corpus investigated.We analysed the forms of 3.5 million reference name declarations in 60 well known Java projects, examining the phrasal structure of names composed of known words and acronyms. The structures found in practice were evaluated against those given in the literature. The use of unknown abbreviations and words, which may pose a problem for program comprehension, was also identified. Based on our observations of the rich diversity of reference names, we suggest issues to be taken into account for future academic research and for improving tools that rely on names as sources of information.

Investigating naming convention adherence in Java references

“…The rule for 'local-variableboolean' inherits the typographic rules from 'local-variable'. The content field overrides the definition in the parent species and allows the use of noun phrases and verb phrases 4 , observed by Liblit et al [7], and of adjectival, adverbial and prepositional phrases, that we observed [13]. Ciphers are the only non-phrasal form of names permitted.…”

“…Liblit et al's observations both increase the variety of phrasal forms expected, and require the division of species into boolean and non-boolean subspecies. Liblit et al 's metaphors have been used as a starting point for the extraction of information from names [5][6] and our previous work confirms the metaphors are widely used [13]. Further, recent research [7][5] [6] [14][13] [9] shows that developers use a range of phrasal structures wider than specified in EJS and JLS.…”

“…We therefore defined a third set of naming conventions that amalgamates the EJS conventions, because of their emphasis on the use of dictionary words, with the observations of phrasal structures found in practice made by Liblit et al [7], Hill [5], Abebe and Tonella [6], Binkley et al [14], and ourselves [13]. We refer to this latter group as AJC, for aggregated Java conventions.…”

“…To ease the check of different selections of rules, we also defined a domain-specific language to define conventions in a simple and declarative way. The language and the checker, called NOMINAL, were informed by our previous study of Java reference names [13] that observed the forms reference names take in practice without a priori judgement about which forms are 'right'. In this paper, we explicitly judge names as conventional or unconventional, depending on their adherence or not to a naming guideline.…”

“…The naming conventions are taken from the "Java Language Specification" [1], the "Elements of Java Style" [2], and studies of Java identifiers in the academic literature [5][6] [7] [13].…”