# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1333

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 1334

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## [Struct field name validate](https://discourse.julialang.org/t/struct-field-name-validate/64499)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 2\
**Last updated:** [July 12, 2021, 12:35pm UTC](https://discourse.julialang.org/t/struct-field-name-validate/64499 "2021-07-12T12:35:57Z")

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Hellow! I am looking for a reliable method to validate structure field names. Structure code is generated based on user input. I think about eval(), but… x = :else exp = :($x = "Oops!"; print($x)) eval(exp) # -\> Oops…

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## [Makie - Default plot color](https://discourse.julialang.org/t/makie-default-plot-color/64494)

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**Author:** [@paurierap](https://discourse.julialang.org/u/paurierap)\
**Replies:** 1\
**Last updated:** [July 12, 2021, 11:58am UTC](https://discourse.julialang.org/t/makie-default-plot-color/64494 "2021-07-12T11:58:14Z")

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While trying to set the attributes of a custom recipe, I am using default\_theme(scene,Mesh), knowing that the default color is :black. My ultimate goal is to set my own default color, but somehow Makie changes any color …

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## [Expression bug?](https://discourse.julialang.org/t/expression-bug/64495)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 0\
**Last updated:** [July 12, 2021, 10:06am UTC](https://discourse.julialang.org/t/expression-bug/64495 "2021-07-12T10:06:45Z")

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Hellow! I use Julia 1.6.1 x = :foo; :(struct Bar $x::Any end) # -\> struct Bar $ x::Any end # Bug? :(struct Bar $x::Any end) # -\> struct Bar foo::Any end # This is ok

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## [Help understanding which changes in HTTP.jl affect this (older) function in Couchzilla.jl. Trying to update the package to julia 1.0 and recent HTTP.jl](https://discourse.julialang.org/t/help-understanding-which-changes-in-http-jl-affect-this-older-function-in-couchzilla-jl-trying-to-update-the-package-to-julia-1-0-and-recent-http-jl/56447)

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**Author:** [@Jon\_Norberg](https://discourse.julialang.org/u/Jon_Norberg)\
**Replies:** 2\
**Last updated:** [March 4, 2021, 5:27am UTC](https://discourse.julialang.org/t/help-understanding-which-changes-in-http-jl-affect-this-older-function-in-couchzilla-jl-trying-to-update-the-package-to-julia-1-0-and-recent-http-jl/56447 "2021-03-04T05:27:18Z")

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Hi, I just wanted to check if someone more knowledgeable in HTTP.jl could help me out with fixing another package that is a bit older and not entirely updated to recent HTTP.jl? Couchzilla.jl is a julia interface to cou…

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## [Implementing singletons for configuration variables](https://discourse.julialang.org/t/implementing-singletons-for-configuration-variables/62177)

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**Author:** [@sapo](https://discourse.julialang.org/u/sapo)\
**Replies:** 7\
**Last updated:** [July 12, 2021, 8:39am UTC](https://discourse.julialang.org/t/implementing-singletons-for-configuration-variables/62177 "2021-07-12T08:39:39Z")

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Hello, I am used to having an object containing configuration variables for my project. For instance, in Java, I use static singletons to ensure those configuration variables are instantiated only once for the whole li…

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## [Revise and const values changed during a session?](https://discourse.julialang.org/t/revise-and-const-values-changed-during-a-session/64372)

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**Author:** [@sapo](https://discourse.julialang.org/u/sapo)\
**Replies:** 2\
**Last updated:** [July 12, 2021, 8:38am UTC](https://discourse.julialang.org/t/revise-and-const-values-changed-during-a-session/64372 "2021-07-12T08:38:03Z")

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Until now, I was used to having a file containing a module with some parameters, usually set with const keyword. This is very similar to a singleton - the design pattern, not the Julian singleton - and guarantees that an…

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## [Error with function, no methods matching](https://discourse.julialang.org/t/error-with-function-no-methods-matching/64489)

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**Author:** [@Broti](https://discourse.julialang.org/u/Broti)\
**Replies:** 6\
**Last updated:** [July 12, 2021, 7:47am UTC](https://discourse.julialang.org/t/error-with-function-no-methods-matching/64489 "2021-07-12T07:47:16Z")

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Hi, I’ve been working on a program recently but I can’t find where I went wrong, I need help. It’s a simple program that makes recurrences. Here’s my code: using NLsolve function systeme!(S,x) S\[1\]=f(f(x\[1\],x\[2\],…

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## [VSCode and Jupyter: TypeError: Cannot read property 'charAt' of undefined](https://discourse.julialang.org/t/vscode-and-jupyter-typeerror-cannot-read-property-charat-of-undefined/58315)

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**Author:** [@AAlshammaa](https://discourse.julialang.org/u/AAlshammaa)\
**Replies:** 6\
**Last updated:** [July 12, 2021, 5:31am UTC](https://discourse.julialang.org/t/vscode-and-jupyter-typeerror-cannot-read-property-charat-of-undefined/58315 "2021-07-12T05:31:13Z")

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I used to use Jupyter Notebooks for Python. I was excited to hear that Jupyter extension supports Julia. However I cannot create more than one code cell, and I get this message. Has anyone run into that? Is there a work…

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## [Allowed types for \`fft()\` and \`ifft()\` when using sparse arrays](https://discourse.julialang.org/t/allowed-types-for-fft-and-ifft-when-using-sparse-arrays/64481)

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**Author:** [@maxkapur](https://discourse.julialang.org/u/maxkapur)\
**Replies:** 0\
**Last updated:** [July 12, 2021, 1:56am UTC](https://discourse.julialang.org/t/allowed-types-for-fft-and-ifft-when-using-sparse-arrays/64481 "2021-07-12T01:56:03Z")

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In the following code, I have commented out all the lines that produce a MethodError: using FFTW, SparseArrays fft(rand(Float64, 50, 50)) fft(rand(ComplexF64, 50, 50)) fft(rand(Float32, 50, 50)) fft(rand(ComplexF32, 50…

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## [What's the strategy for marking a broken test that you expect to throw when it's not broken?](https://discourse.julialang.org/t/whats-the-strategy-for-marking-a-broken-test-that-you-expect-to-throw-when-its-not-broken/64385)

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**Author:** [@NHDaly](https://discourse.julialang.org/u/NHDaly)\
**Replies:** 4\
**Last updated:** [July 12, 2021, 1:47am UTC](https://discourse.julialang.org/t/whats-the-strategy-for-marking-a-broken-test-that-you-expect-to-throw-when-its-not-broken/64385 "2021-07-12T01:47:13Z")

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I have a function that should be throwing an exception, but currently it’s not. I want to indicate that the not-throwing behavior is broken. I tried this, but it doesn’t work, because the @test\_throws records its failur…

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## [The mime type of julia code, and it's usage in show and repr](https://discourse.julialang.org/t/the-mime-type-of-julia-code-and-its-usage-in-show-and-repr/64465)

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**Author:** [@binary\_cat](https://discourse.julialang.org/u/binary_cat)\
**Replies:** 1\
**Last updated:** [July 11, 2021, 11:07pm UTC](https://discourse.julialang.org/t/the-mime-type-of-julia-code-and-its-usage-in-show-and-repr/64465 "2021-07-11T23:07:16Z")

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I can’t find anything about it online, and there don’t seem to be any methods using it in julia, so I decided to ask here. Something like text/julia (or maybe text/x-julia for standard compliance?) is what I would expec…

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## [\[ANN\] Configurations.jl - Options/Configurations made easy](https://discourse.julialang.org/t/ann-configurations-jl-options-configurations-made-easy/50669)

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**Author:** [@Roger-luo](https://discourse.julialang.org/u/Roger-luo)\
**Replies:** 26\
**Last updated:** [July 11, 2021, 11:00pm UTC](https://discourse.julialang.org/t/ann-configurations-jl-options-configurations-made-easy/50669 "2021-07-11T23:00:12Z")

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I made a small package Configurations.jl to separate the utilities we wrote for Pluto.jl and Comonicon.jl for parsing configurations/options from TOML files and kwargs and serialize them back. (there are still 3 days le…

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## [Metaprogramming with Structure: Converting Dictionary to Structure](https://discourse.julialang.org/t/metaprogramming-with-structure-converting-dictionary-to-structure/63861)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 14\
**Last updated:** [July 11, 2021, 10:40pm UTC](https://discourse.julialang.org/t/metaprogramming-with-structure-converting-dictionary-to-structure/63861 "2021-07-11T22:40:46Z")

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Dear Julian colleagues, I am reading the options of my model from TOML file into Structure. With the following steps: The TOML writes into a Dict: Than I am writing a code to parse Dict into Structure The code works…

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## [China's Alternative To GSoC 2021: 14 Julia related programs!](https://discourse.julialang.org/t/chinas-alternative-to-gsoc-2021-14-julia-related-programs/64473)

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**Author:** [@ImreSamu](https://discourse.julialang.org/u/ImreSamu)\
**Replies:** 0\
**Last updated:** [July 11, 2021, 9:44pm UTC](https://discourse.julialang.org/t/chinas-alternative-to-gsoc-2021-14-julia-related-programs/64473 "2021-07-11T21:44:55Z")

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Summer-2022 some examples: “Differentiating sparse matrix operations with reversible programming” “Add performant image processing algorithms” “Wide-range JuliaImages demos and missing functionalities” “Implement Mul…

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## [WARNING: both A and B export "func"; uses of it in module C must be qualified](https://discourse.julialang.org/t/warning-both-a-and-b-export-func-uses-of-it-in-module-c-must-be-qualified/64402)

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**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 4\
**Last updated:** [July 11, 2021, 8:12pm UTC](https://discourse.julialang.org/t/warning-both-a-and-b-export-func-uses-of-it-in-module-c-must-be-qualified/64402 "2021-07-11T20:12:19Z")

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TL; DR) julia\> includet("test/algorithms/deterministic\_behavioural\_cloning.jl") \[ Info: Precompiling Aerobatics \[3eaf170c-6d53-4308-86e7-def0ff749179\] WARNING: both BipartiteGraphs and Symbolics export "degree"; uses of…

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## [What is meaning of M1, rpath?](https://discourse.julialang.org/t/what-is-meaning-of-m1-rpath/64452)

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**Author:** [@Ravinder\_Ram](https://discourse.julialang.org/u/Ravinder_Ram)\
**Replies:** 4\
**Last updated:** [July 11, 2021, 5:08pm UTC](https://discourse.julialang.org/t/what-is-meaning-of-m1-rpath/64452 "2021-07-11T17:08:35Z")

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## [Syntax for binding type paramaters in a function with a return type is obscure and unintuitive](https://discourse.julialang.org/t/syntax-for-binding-type-paramaters-in-a-function-with-a-return-type-is-obscure-and-unintuitive/63768)

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**Author:** [@binary\_cat](https://discourse.julialang.org/u/binary_cat)\
**Replies:** 7\
**Last updated:** [July 11, 2021, 4:44pm UTC](https://discourse.julialang.org/t/syntax-for-binding-type-paramaters-in-a-function-with-a-return-type-is-obscure-and-unintuitive/63768 "2021-07-11T16:44:18Z")

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I’ve been having trouble with this, and I finally found out why. It has to do with the precedence of :: and where in function signatures. Here’s an example of where this goes wrong: firstint(a::Vector{T})::Int where {…

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## [Parallelism helper tool: Intel Advisor](https://discourse.julialang.org/t/parallelism-helper-tool-intel-advisor/64454)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 1\
**Last updated:** [July 11, 2021, 1:43pm UTC](https://discourse.julialang.org/t/parallelism-helper-tool-intel-advisor/64454 "2021-07-11T13:43:47Z")

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https://software.intel.com/content/www/us/en/develop/tools/oneapi/components/advisor.html#gs.63b72l The tool supports C, C++, Fortran, Data Parallel C++ (DPC++), OpenMP\*, and Python Supposedly it diagnoses parallelis…

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## [Support \`@threads\` for a lazy object](https://discourse.julialang.org/t/support-threads-for-a-lazy-object/64458)

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**Author:** [@jling](https://discourse.julialang.org/u/jling)\
**Replies:** 0\
**Last updated:** [July 11, 2021, 11:39am UTC](https://discourse.julialang.org/t/support-threads-for-a-lazy-object/64458 "2021-07-11T11:39:01Z")

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Say I have a big LazyArray with size 10^5 and the underlying structure is that every 5000 entries are in a “chunk” and one has to read and decompress a chunk together. I have implemented getindex() for LazyArray and it …

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## [Increase performance in string comparison with sub-dataframes or sub-arrays](https://discourse.julialang.org/t/increase-performance-in-string-comparison-with-sub-dataframes-or-sub-arrays/64392)

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**Author:** [@bojusemo](https://discourse.julialang.org/u/bojusemo)\
**Replies:** 5\
**Last updated:** [July 11, 2021, 10:30am UTC](https://discourse.julialang.org/t/increase-performance-in-string-comparison-with-sub-dataframes-or-sub-arrays/64392 "2021-07-11T10:30:14Z")

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Hello, I am new at programming and hope you guys can give me a hand, please. I have three plain text files with columns called ID\_# File a Header Header Header Header Header ID\_1 ID\_5 ID\_6 ID\_7 ID\_8 File b ID\_…

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## [PDF archive of past JuliaCon presentations?](https://discourse.julialang.org/t/pdf-archive-of-past-juliacon-presentations/64253)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 4\
**Last updated:** [July 11, 2021, 10:04am UTC](https://discourse.julialang.org/t/pdf-archive-of-past-juliacon-presentations/64253 "2021-07-11T10:04:00Z")

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Question is in the title. Thank you.

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## [Unable to install or update package](https://discourse.julialang.org/t/unable-to-install-or-update-package/64153)

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**Author:** [@RolfSand](https://discourse.julialang.org/u/RolfSand)\
**Replies:** 10\
**Last updated:** [July 11, 2021, 6:40am UTC](https://discourse.julialang.org/t/unable-to-install-or-update-package/64153 "2021-07-11T06:40:02Z")

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I receive the following error: ERROR: expected package IJulia \[7073ff75\] to be registered

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## [Question on Quora](https://discourse.julialang.org/t/question-on-quora/64451)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 0\
**Last updated:** [July 11, 2021, 6:23am UTC](https://discourse.julialang.org/t/question-on-quora/64451 "2021-07-11T06:23:17Z")

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For anyone who uses Quora, there is a thread below. I am looking for a reference to the ballista/catapult example where SciML and Flux are combined. I think this was a talk by Chris Rackaucas - but cannot find the exac…

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## [How do use Hyperopt.jl's Bayesian Hyperparameter Optimization feature?](https://discourse.julialang.org/t/how-do-use-hyperopt-jls-bayesian-hyperparameter-optimization-feature/64447)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 3\
**Last updated:** [July 11, 2021, 6:19am UTC](https://discourse.julialang.org/t/how-do-use-hyperopt-jls-bayesian-hyperparameter-optimization-feature/64447 "2021-07-11T06:19:21Z")

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The package says it has Bayesian Optimization but I can’t find much info on how to use it. Does it go by some other name?

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## [Why is this @vlplot blank?](https://discourse.julialang.org/t/why-is-this-vlplot-blank/64369)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 5\
**Last updated:** [July 11, 2021, 5:40am UTC](https://discourse.julialang.org/t/why-is-this-vlplot-blank/64369 "2021-07-11T05:40:34Z")

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I use this command: DataFramesMeta.@select(@where(dftrans, .! ismissing.(:PreScore) .& .! ismissing.(:Group)), :Group,PreScore = Float64.(:PreScore)) |\> @vlplot(mark={:area, fillOpacity=.5},x={"PreScore:q",scale={domain…

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## [Error with CircularBufferArrays in ReinforcementLearning.jl](https://discourse.julialang.org/t/error-with-circularbufferarrays-in-reinforcementlearning-jl/63769)

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**Author:** [@SatvikDuddukuru](https://discourse.julialang.org/u/SatvikDuddukuru)\
**Replies:** 5\
**Last updated:** [July 11, 2021, 3:07am UTC](https://discourse.julialang.org/t/error-with-circularbufferarrays-in-reinforcementlearning-jl/63769 "2021-07-11T03:07:40Z")

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I made a Connect 4 Environment with ReinforcementLearning.jl: begin mutable struct Connect4Env \<: AbstractEnv board::Array{Int,2} current\_player::Int full\_columns::Array{Int,1} is\_terminated::Bool Connect4E…

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## [String interpolation in markdown admonition in Pluto](https://discourse.julialang.org/t/string-interpolation-in-markdown-admonition-in-pluto/63795)

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**Author:** [@dpkwhan](https://discourse.julialang.org/u/dpkwhan)\
**Replies:** 2\
**Last updated:** [July 11, 2021, 2:41am UTC](https://discourse.julialang.org/t/string-interpolation-in-markdown-admonition-in-pluto/63795 "2021-07-11T02:41:43Z")

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In Pluto, the following code snippet fails to properly interpolate the values. How to fix it? begin todo\_index = 3 md""" !!! todo "Todo $(todo\_index)" This is todo #$(todo\_index) """ end

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## [Debugging some wrapped Fortran code](https://discourse.julialang.org/t/debugging-some-wrapped-fortran-code/46610)

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**Author:** [@danielmatz](https://discourse.julialang.org/u/danielmatz)\
**Replies:** 7\
**Last updated:** [July 11, 2021, 12:15am UTC](https://discourse.julialang.org/t/debugging-some-wrapped-fortran-code/46610 "2021-07-11T00:15:56Z")

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I’ve created a Julia package that provides a wrapper around a Fortran subroutine. I’d like to build my Fortran shared library with debug information and use gdb to set a break point in the Fortran code. Is that possible …

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## [Please help understand the syntax](https://discourse.julialang.org/t/please-help-understand-the-syntax/64423)

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**Author:** [@dpkwhan](https://discourse.julialang.org/u/dpkwhan)\
**Replies:** 5\
**Last updated:** [July 10, 2021, 11:13pm UTC](https://discourse.julialang.org/t/please-help-understand-the-syntax/64423 "2021-07-10T23:13:12Z")

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In the source code for summarysize.jl Line 63: (ss::SummarySize)(@nospecialize obj) = \_summarysize(ss, obj) Line 88 and 89: (::SummarySize)(obj::Symbol) = 0 (::SummarySize)(obj::SummarySize) = 0 Can someone help exp…

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## [\[ANN\] DataFramesMeta 0.8.0 release](https://discourse.julialang.org/t/ann-dataframesmeta-0-8-0-release/64416)

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**Author:** [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Replies:** 4\
**Last updated:** [July 10, 2021, 10:44pm UTC](https://discourse.julialang.org/t/ann-dataframesmeta-0-8-0-release/64416 "2021-07-10T22:44:46Z")

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I am happy to announce the 0.8.0 release of DataFramesMeta. This comes shortly after the 0.7.0 release. We are working quickly and implementing breaking changes in pursuit of a 1.0 release. The changes are @where ha…

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