- check the readability of lower and upper case "i" (india) against the number "1" (one)and the lower and upper case "l" (lima).
- Check the readability of the lower and upper case "o" (oscar) against the number "0".
- check if the font can be used monospaced with being reasonable to good readability.
If it passes those checks then it is often good enough for me.
- Is there a lighter weight variant from which one can steal ()[]{} ? Essential for Lisp programming, nice for every language.
My current winner is Roboto Mono Regular, with brackets borrowed from Roboto Mono Light. The font disappears on me (attitude takes bandwidth) and one would never know I played with the brackets till one goes back to another font, and it becomes obvious brackets on a Retina display have no business having the same weight as body text.
Sample ('Zoom Out' for realistic scale): https://www.math.columbia.edu/~bayer/etc/RobotoLisp.png
I'm definitely going to try this out.