> I'm interested in functional programming, programming language theory, and type theory. These interests caused me to discover pure math (such as category theory)...I applied as a CS major to several colleges where PL theory had an academic presence
It's awesome that you know what you're interested and exploring it, but I'd caution against committing so heavily into one specific part of CS when you applying as an undergrad--that almost read like someone applying to grad school. Most of your courses will be pretty generic (as opposed to specialized). Between those, humanities, other science classes, etc., I'd actually suggest trying to expose yourself to as much as possible. If you still have that passion in four years, by all means go for the master's, but also:
I don't mean any of this as discouragement, just that there's so much out there, and so many rich, unexpected connections to make, there will be time to focus later. But don't be undeclared, either.
I'll echo this. This kind of laser focus narrows options a lot after university as well. The dirty secret about most "ML" jobs is that a lot of the work looks like the things professors delegate to grad and undergrad students: data collection, data cleaning, automation, etc. The actual ML is a fraction of the work at best.
Same goes for computer science as such. Most of the work is grunt work in testing, debugging, peer review, etc. As you advance, there may be more time available for pure math work, but that means the amount of communication just goes way up: writing, peer reviews, presentations, management, managing up, etc.
Point being, don't be afraid to develop your application skills. Things like teamwork and communication matter a lot. Computer science is the common major, but most demand is for coders. Of course, what companies need is typically software engineers and (good!) software project management.
Thank you for the advice. Other people have told me this as well. I chose a school where PL theory has a presence so I can pursue my specific interests, but I expect that the undergraduate CS curriculum will also give me a well-rounded CS education.
It's awesome that you know what you're interested and exploring it, but I'd caution against committing so heavily into one specific part of CS when you applying as an undergrad--that almost read like someone applying to grad school. Most of your courses will be pretty generic (as opposed to specialized). Between those, humanities, other science classes, etc., I'd actually suggest trying to expose yourself to as much as possible. If you still have that passion in four years, by all means go for the master's, but also:
http://matt.might.net/articles/phd-school-in-pictures/
I don't mean any of this as discouragement, just that there's so much out there, and so many rich, unexpected connections to make, there will be time to focus later. But don't be undeclared, either.