CODEWITHSUNDEEP
macrosjulia
Georgery
Georgery

Reputation: 8127

Try-Catch Macro in Julia

I have the following functions.

foo(x) = x + 1
bar(x) = x * 2

I use them in a wrapper function (not sure whether this is even important).

function baz(x)
    d = Dict{Symbol,Any}()
    d[:foo] = foo(x)
    d[:bar] = bar(x)
    return d
end

The problem is that foo() and bar() can fail, and I want the code to continue running in this case. Introducing try catch statements would make the code very messy, however. So, is there maybe one of the following two solutions out there, that could make this easier?

Dream Solution

A macro that I could just write in front of d[:foo] = foo(x) and which in case of failure would write a default value do d[:foo].

Also-a Solution

A macro that would just continue if the code fails.

Upvotes: 2

Views: 324

Answers (1)

Georgery
Georgery

Reputation: 8127

So, I managed to do the following. However, I have no clue if this is in any way good style.

macro tc(ex)
    quote
        try
            $(esc(ex))
        catch
            missing
        end
    end
end

@tc foo(1)
1

@tc foo("a")
missing

Note the $(esc(ex)). This is important. If the expression is not escaped, the macro will work as expected in the global scope but not inside a function (as in the question). If anyone can provide a crisp explanation of why this is the case, please add a comment.

Upvotes: 1

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