JuliaLang/julia

parse command interpolations at parse time

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#3,150 opened on May 19, 2013

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 (13 comments) (0 reactions) (0 assignees)Julia (48,709 stars) (5,773 forks)batch import
help wantedparser

Description

It would be nice to have a way to "double interpolate" a variable with respects to nested possible interpolation contexts to make it easier to write quoted code blocks that wants to interpolate a variable inside a string. e.g., so the below code echos "hi". Not sure what the best way to go about that is.

macro example()
 f="hi"
 quote
  run(`echo $$f`)
 end
end

Contributor guide

Tech stack
None
Domain
backend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Familiarity with Julia macrosKnowledge of Julia's expression interpolation
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
15
Research direction
Examine the Julia parser's handling of string interpolation and command quotes. The issue suggests adding a way to double interpolate, which would require changes to the parser's macro expansion code. Look at relevant files such as `src/julia parser.scm` and `base/parse.jl`. Also review existing discussions in the issue comments for potential approaches.