@technomancy I'm not 100% sure it's what @mattly was thinking of, but I think so.
Anyway, a language called Pony makes it a syntax error to mix operators without parens: i.e. 1+2+3 is fine but 1+2*3 is a syntax error.
PEDMAS or BODMAS or whatever can go eat a bag of Dick's (meaning the burger place, of course).