If you just walked up to me out of the blue and asked "what computer language do you know is the worst for processing strings?", well, technically I might answe

If you just walked up to me out of the blue and asked "what computer language do you know is the worst for processing strings?", well, technically I might answer "assembler", but if you excluded that, my next answer would be C. Furthermore, you want some sort of AST representation, at one level of convenience or another (I include this compgen-style "being 'in' the AST" to be included in that, even if it doesn't necessarily directly manipulate AST nodes), and C isn't particularly great at manipulating those, either, in a lot of different ways. A consequence of C being the definitive language that pretty much every other language has had to react to, one way or another through however many layers of indirection, for the past 40+ years, is that pretty much every language created since then is better than C at these things. C's pretty long in the tooth now, even with the various polishings it has received over the years.