I hear some guys wrote a pretty cool operating system like that!
Also, you would have to give up syntax coloring and style and font variations.
Finally, chances are that some characters (braces, asterisk, plus sign) from your programming language take up more than one braille character. Real nerds would hack their character-to-braille pattern translator to optimize that translation table, but the price you pay for that is that you will have to cope with multiple mappings. Actually, you would have to do that anyways, as there is disagreement about the encoding to use, even for digits, and because the U.S. frequently uses a contracted braille system (where, for example, the single-letter word 't' must be read as 'the' where appropriate; that 'where appropriate' is for the reader to guess at)
I'm pretty sure ed was dead by the time those were invented, the wiki claims the "one of the first" syntax highlighting editors was in 85.