Expr pattern is not working with Float

[Roger-luo]

MWE:

function foo(ex)
    @match ex begin
        Expr(:call, sin, 2π) => 0
        _ => "unknown"
    end
end

it seems there is no way to eval numerics in the pattern?

[Roger-luo]

should be &2π, this part is a bit intuitive to me. I'm wondering if it is possible to just write 2π without making ambiguity?

[thautwarm]

It's &(2π).

I'm wondering if it is possible to just write 2π without making ambiguity?

It's impossible, I remember we used to discuss about this.

Expr(:call, 2, :π) shouldn't match Expr(:call, 2, π), does it make sense?

• :π is a pattern to match a symbol :π,
• π is a pattern to capture the positional value as variable π,
• &π is a pattern to match the positional value with the variable π in current scope.

[Roger-luo]

yeah, closed.