Missing matrix division dispatches

[pao]

There's no dispatch for matrix division between Int32 and Float64, and probably others.

julia> [1 0 0; 0 1 0; 0 0 1]\[1.;2;4]
no method /(Array{Float64,1},Array{Int32,2})
 in method_missing at /home/patrick/julia/j/base.j:58
 in \ at /home/patrick/julia/j/operators.j:59

julia> [1. 0 0; 0 1 0; 0 0 1]\[1;2;4]
no method /(Array{Int32,1},Array{Float64,2})
 in method_missing at /home/patrick/julia/j/base.j:58
 in \ at /home/patrick/julia/j/operators.j:59

After watching Jeff's presentation, I was feeling confident I could figure out how to fix it. Unfortunately my grep-fu is failing me and I can't track down where AbstractMatrix/AbstractMatrix is defined. Any pointers?

[StefanKarpinski]

The file is abstractarray.j, but I can't promise that's the right place to do it. Concrete array stuff is defined in array.j.

[pao]

AbstractArray/Number and Number/AbstractArray, but not AbstractArray/AbstractArray are in abstractarray.j; array.j doesn't seem to define matrix division either. I also checked linalg.j. I can see that it actually works, though, as long as the number types line up. (We need a debugger!)

[StefanKarpinski]

We definitely need a debugger. Jeff and I concocted a plan for a debugger which basically involved JITing debug versions of code with debug hooks inserted into the AST at appropriate places. This is kind of similar to how I believe the perl debugger works.

[Keno]

LLVM has debugging capabilities for JIT with gdb. We could probably make use of that.

[ViralBShah]

Matrix division stuff is in linalg_lapack.j. Just need to add a bunch of methods that do the right promotions.

[pao]

Excellent, found it. Thanks for the pointer, Viral!