Miss Dada  🏳️‍⚧️

I didn’t even know you *could* have something other than parser(lexer(input))

You can't parse C with parser(lexer(input))

this isn't *strictly* true (I mean you can parse any language with a composition of those functions, even if they're pure, for given definitions of those functions). Like we *could* build a ruby parser where the lexer was a pure scanner, but it would be very hard.

where does the lexer use state from the parser?

Symbol table to disambiguate typedefs in expressions like (A) * B.

is the ambiguity here that this means "A times B" or "deref B and cast to A"

Yes

Or from a lexer point of view it's what is A, since most C lexers chose to have types be a separate token class