Semantics-preserving inlining for metaprogramming

Abstract

Inlining is used in many di erent ways in programming languages: some languages use it as a compiler-directive solely for optimization, some use it as a metaprogramming feature, and others lay their design in-between. This paper presents inlining through the lens of metaprogramming and we describe a powerful set of metaprogramming constructs that help programmers to unfold domain-speci c decisions at compile-time. In a multi-paradigm language like Scala, the concern for generality of inlining poses several interesting questions and the challenge we tackle is to o er inlining without changing the model seen by the programmer. In this paper, we explore these questions by explaining the rationale behind the design of Scala-3's inlining capability and how it relates to its metaprogramming architecture. CCS Concepts: • Software and its engineering → Object oriented languages; Functional languages; Macro languages.