kerryb

kerryb

I have some AST rewriting code (using Sourceror) that has started failing in Elixir 1.18 – I believe because unquote has become stricter about valid AST, whereas in earlier versions it was only an issue within macros.

The issue is that it’s trying to generate code containing a ~D[...] sigil. It works in Elixir 1.17:

iex(1)> quote do: unquote(~D[2025-01-07])
~D[2025-01-07]

But not in 1.18:

iex(1)> quote do: unquote(~D[2025-01-07])
** (ArgumentError) tried to unquote invalid AST: ~D[2025-01-07]
Did you forget to escape term using Macro.escape/1?
    (elixir 1.18.1) src/elixir_quote.erl:542: :elixir_quote.argument_error/1
    iex:1: (file)

I can use Macro.escape as suggested, but this inserts the date as a raw map instead of a sigil. This works, but doesn’t look great in the generated code:

iex(2)> quote do: unquote(Macro.escape(~D[2025-01-07]))
{:%{}, [],
 [__struct__: Date, calendar: Calendar.ISO, day: 7, month: 1, year: 2025]}

Is there some way to end up with a call to the ~D macro in the generated code, rather than the resulting struct/map?

Showing Posts 1 to 2

LostKobrakai

LostKobrakai

The quote/unquote has nothing to do with how the final generated code looks like. They’re just means of generating AST/injecting given AST in the resulting AST. You’d need to figure out the correct AST you want to return for sourceror:

iex(1)> quote do: ~D[2024-12-12]
{:sigil_D, [delimiter: "[", context: Elixir, imports: [{2, Kernel}]],
 [{:<<>>, [], ["2024-12-12"]}, []]}

Depending on what input you actually have you can build that AST for the return value.

iex(1)> quote do: unquote(~D[2025-01-07])
~D[2025-01-07]

This here is basically a noop. It does/did nothing.

kerryb

kerryb OP

The quote/unquote has nothing to do with how the final generated code looks like. They’re just means of generating AST/injecting given AST in the resulting AST. You’d need to figure out the correct AST you want to return for sourceror:

iex(1)> quote do: ~D[2024-12-12]
{:sigil_D, [delimiter: "[", context: Elixir, imports: [{2, Kernel}]],
 [{:<<>>, [], ["2024-12-12"]}, []]}

Thanks, that makes sense.

This here is basically a noop. It does/did nothing.

Yeah, in the real code there was a lot more stuff in the quote.

— All posts loaded —

Where Next? Top

Trending in Questions Top

stjefim
Hello! Suppose you are building workflow (order / task / payment) processing system with the following requirements: Each workflow con...
New
water
I’m aware of 2 such projects, are there others? git: GitHub - team-alembic/realworld: A fullstack Phoenix LiveView application with back...
New
itzmidinesh
Hi all, I’m working on a Phoenix project where I need to make external HTTP requests and I’m trying to choose between Req and HTTPoison....
New
peck
Hi everyone. My team and I have been working on a fairly modest app based around video streaming and chat, but we’ve landed a customer t...
New
leoschweizer
Hi, we run different LLM models across a cluster, with each node loading a configurable subset. Model-specific queues let nodes consume ...
New
csmr
Hi all, I’m new here and would like to hear peoples views on my Elixir/Phoenix based game-engine! :smiley: Mutonex gamedesign was finish...
New
Stef-Verniers
Hello I’ve been coding in Elixir for almost two years now because of my current job where we implemented Elixir in our application. But ...
New

Other Trending Topics Top

dominicletz
Hey there, I haven’t seen a list of useful Elixir specific skills for the popular AI tools yet so I’m starting one here with my first. ...
New
mudasobwa
I fully migrated to my own harness from Anthropic/Gemini and I think it’s time to share it. Welcome DSH, the DeepSeek Harness, fully writ...
New
KristerV
Hey. Is there anyone here who creates agents in their apps? Not talking about using agents, but creating them. I’m finding it pretty diff...
New
jimsynz
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New
webofbits
With AI doing more of the implementation work, I’ve been wondering how much coding I should deliberately keep doing myself. My main conc...
#ai
New
OndrejValenta
(I just needed to vent somewhere and LinkedIn is full of hope, or hype, I’m not sure which exactly) AI dream has many faces, but general...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews