I am trying to write a macro that defines a solver type with a set of parameters. The idea is to write something like the following: @simsolver MySolver begin @param a = 1.0 @param b = false @param c end and get: @with_kw struct MySolverParam a = 1.0 b = false c end struct MySolver …

I recommend you read the hygiene section in the docs. I also recommend (again) using @macroexpand to see what your macro is doing so you can look for what to change. The output of the macro should be the a quoted code that you originally wanted. If I use your macro as defined and test on the examp…

That is a beautiful writeup @favba ! Thanks for sharing! I will try digest it locally and play around with @macroexpand as you suggested. First time playing with macros, but your answer is helping a lot already to understand the machinery.

[image] favba: julia> ex.args[3].args 6-element Array{Any,1}: :( # REPL[40], line 1:) :(@param a = 1.0) :( # REPL[40], line 1:) :(@param b = false) :( # REPL[40], line 1:) :(@param c) Quick question, these lines with REPL refer to what?

I really don’t know. Maybe they’re newline characters? REPL[40] refers to the line (40) of the “file” where the block was written (this case in the julia terminal: Read-Evaluate-Print-Loop).

That is my guess too :slight_smile: In any case, I am really enjoying playing with macros now after your very clear explanation :100:

I got all that figured out this past week and was really excited about it. I’m trying to find new places to apply this awesome macro power :smile:

They definitively refer to the ; used at the expression creation.

I filtered the parameters prefixed with @param, but now I am wondering how to paste each entry of the vector in the body of the struct, one per line. Do you know a way? macro simsolver(solver, body) solverparam = Symbol(solver,"Param") body = filter(arg -> arg.head == :macrocall, body.…

I’m not on my pc anymore. But try figuring out how a struct expression is constructed with the same trick above. It will probably be something like ex.head = :struct and then the first argument will be the struct name and the rest the expressions to be evaluated inside the struct. Then you can manua…

Asa a slightly unrelated note, I’m of the opinion that one should give great thought before making an API based on macros. From a user’s point of view, as soon as one sees a macro, it is hard to know what will happen since the macro can rewrite the code to whatever it wants. In other words, ones Ju…

Defining a solver type with macros

General Usage

juliohm September 12, 2017, 8:40pm 21

I will create a separate thread for this question, this post is too long already:

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Defining a solver type with macros

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