On the Structure and Semantics of Identifier Names Containing Closed Syntactic Category Words

TL;DR

This paper explores the linguistic structure of identifier names in code, focusing on closed syntactic categories, and introduces a new dataset to analyze how naming patterns relate to program behavior.

Contribution

It presents the first detailed analysis of closed syntactic categories in identifier names and introduces the CCID dataset for studying their role in expressing program semantics.

Findings

Recurring naming structures encode control flow and data transformation.

Closed-category patterns are central to expressing temporal and behavioral concepts.

The study provides an empirical foundation for understanding naming conventions in software.

Abstract

Identifier names are crucial components of code, serving as primary clues for developers to understand program behavior. This paper investigates the linguistic structure of identifier names by extending the concept of grammar patterns, which represent the part-of-speech (PoS) sequences underlying identifier phrases. The specific focus is on closed syntactic categories (e.g., prepositions, conjunctions, determiners), which are rarely studied in software engineering despite their central role in general natural language. To study these categories, the Closed Category Identifier Dataset (CCID), a new manually annotated dataset of 1,275 identifiers drawn from 30 open-source systems, is constructed and presented. The relationship between closed-category grammar patterns and program behavior is then analyzed using grounded-theory-inspired coding, statistical, and pattern analysis. The results reveal recurring structures that developers use to express concepts such as control flow, data transformation, temporal reasoning, and other behavioral roles through naming. This work contributes an empirical foundation for understanding how linguistic resources encode behavior in identifier names and supports new directions for research in naming, program comprehension, and education.