I would like to contruct a type using meta programming. More specific,I need a tuple type like Tuple{Vector{String}, Vector{String}} . Constructing a value is quite easily possible, e.g. ex = Expr(:tuple) push!(ex.args, 1) push!(ex.args, 2) with eval(ex) resulting in the tuple value (1,2) B…

[image] Thomas008: However, using the symbol curly, using ex = Expr(:curly) did not work to get a well-formed expression so far. I would be very happy if you had a suggesion. Expr(:curly, :Tuple, :Int, :Char) works just fine to construct :(Tuple{Int, Char}), for example. PS. Obligatory wa…

First, I’ll echo the above that there might be a better way to do this without metaprogramming. Metaprogramming is difficult to write and read and it can be brittle. To answer your specific query based on the dump you gave (less args[4], which should not actually be present): julia> Expr(:curly, :…

In earlier steps, typing source code into quoted expressions and interpolation could be easier than constructing and mutating Expr directly: julia> x = :(Vector{String}) :(Vector{String}) julia> :(Tuple{$x, $x}) :(Tuple{Vector{String}, Vector{String}}) julia> :(Tuple{$( (x, x)... )}) :(Tuple{Vect…

How to construct a type using Meta programming?

General Usage

stevengj April 9, 2026, 2:15pm 2

Expr(:curly, :Tuple, :Int, :Char) works just fine to construct :(Tuple{Int, Char}), for example.

PS. Obligatory warning that metaprogramming is the wrong tool 99% of the time … but is very useful in remaining 1%.

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How to construct a type using Meta programming?

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