Record more stuff!
During my work on IRTracker.jl, I noticed that for my purposes -- dynamic tracking of computation graphs, including nested functions and control flow -- Cassette is too abstract, and IRTools is too low-level.
I ended up with an implementation based on IRTools that essentially replicates part of Cassette's interface (canrecur, something like overdub, contexts), but for more than just function calls.
The goal of this project would be to factor out those parts of IRTracker into a reusable system.
Currently, it exists only in my head, though.
geom(n, β) = rand() < β ? n : geom(n + 1, β)
1: (%1, %2, %3)
%4 = Main.rand()
%5 = %4 < %3
br 2 unless %5
return %2
2:
%6 = %2 + 1
%7 = Main.geom(%6, %3)
return %7
should transform into something like
1: (%1, %4, %2, %3)
%5 = quoted(%4, Arg, :(%1), %1)
%6 = overdub(%4, %5)
%7 = quoted(%4, Arg, :(%2), %2)
%8 = overdub(%4, %7)
%9 = quoted(%4, Arg, :(%3), %3)
%10 = overdub(%4, %9)
%11 = quoted(%4, Const, Main.rand)
%12 = quoted(%4, Call, :(%4), %11)
%13 = overdub(%4, %12)
%14 = quoted(%4, Const, <)
%15 = quoted(%4, Call, :(%5), %14, %12, %9)
%16 = overdub(%4, %15)
%17 = quoted(%4, CondBranch, 2, %15)
%18 = quoted(%4, Return, %7)
br 2 (%17) unless %16
br 3 (%18)
2: (%19)
%20 = overdub(%4, 19)
%21 = quoted(%4, Const, +)
%22 = quoted(%4, Const, 1)
%23 = quoted(%4, Call, :(%6), %21, %7, %22)
%24 = overdub(%4, %23)
%25 = quoted(%4, Const, Main.geom)
%26 = quoted(%4, Call, :(%7), %25, %23, %9)
%27 = overdub(%4, %26)
%28 = quoted(%4, Return, %27)
br 3 (%28)
3 (%29):
%30 = overdub(%4, %29)
return %30
where %4 is the context object.