I'd really love to do this, but there isn't a single editor I know of that can do it well. Because, for me, the trick would be to have different fonts and style

I'd really love to do this, but there isn't a single editor I know of that can do it well. Because, for me, the trick would be to have different fonts and styles to help give the code context. Eg, the line defining a new method should look like a sub-headline, while the contents of a comment should look like a quote, variable names in italics etc. Editors are definitely starting to get there, with colour support coming along, but there's a long way to go.