i'm going to design and build a "programmer's numpad", because I'm sick of awkward hand movements for writing brackets with numbers and commas and spaces etc. here's the first draft. make your modifications here: http://www.keyboard-layout-editor.com/#/ i'm thinking of adding another column, putting something between the numbers and the plus/minus.
My one concern with this idea is that it requires a lot of wrist/arm movement away from the home row and main area of the keyboard.
You have all of the major programming symbols on here - which is great - but also implies that you'd remove your right hand from it's main position in the right half of the keyboard to reach to the number pad, then move back, find the home row, keep typing, repeat, etc.
That feels a lot more clunky and unnecessary than pressing alt-gr/shift/option+key on most regular layouts IMO.
(This isn't meant to be a harsh criticism, I love the idea to make a more useful numerpad but given where a number pad is located it doesn't feel like it would help typing efficiency for coding at all)