# Macro Expressiveness and Nesting

**URL:** <https://racket.discourse.group/t/macro-expressiveness-and-nesting/2313>\
**Category:** Questions & Answers\
**Tags:** macro\
**Created:** [September 15, 2023, 3:27pm UTC](https://racket.discourse.group/t/macro-expressiveness-and-nesting/2313 "2023-09-15T15:27:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![bakgatviooldoos](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/bakgatviooldoos/32/1381_2.png) [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\
**Post date:** [September 15, 2023, 3:27pm UTC](https://racket.discourse.group/t/macro-expressiveness-and-nesting/2313/1 "2023-09-15T15:27:17Z")

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Hi, Racket Discourse.

Might be I'm overthinking the situation, but I thought I would ask anyway.

Is there a known theorem/result/conjecture about the expressiveness of macros, in terms of how many layers of nesting you'd need to express a particular (halting?) computation? I understand that this might be a broad question which doesn't necessarily apply to all implementations of macros, or that I might be confusing what "computation" even means in this case.

I got to thinking about the question because of [this thread](https://racket.discourse.group/t/macro-monstrosity-some-questions/2311/5), where I ask about macros for replacing some pattern with the appropriately escaped `...` used in nested macros, i.e. `...`, `(... ...)`, `((... ...) (... ...))`, and so on. But why would I ever need that level of nesting? 🤷‍♂️

**Edit** : To clarify my point a bit, what I have in mind is some "principle" or even a rule of thumb that a macro that is nested past a certain degree [in its definition] could just as well be expressed using a combination of shallower macros; but, not necessarily below this degree.