intermediate parser
add newline
basic character parser
parse #t, #f, #\space, #\newline
parse integer and rational
make sure we do not consume after eof
parse inexact numbers
new function Complex<T>::abs
make clean
parse decimal float numbers
complex number parser
parse list
parse dot separated cons
parse + and - as identifier
accept ... as identifier
support number literal starting with '.'
separate datum from parser
eval skeleton
basic repl
make clean